1. Legătura covalentă este legătura chimică ce se stabileşte: a) prin punere în comun de electroni; b) prin transfer de electroni; c) prin punere în comun sau prin transfer de electroni. 2. Legătura covalentă se stabileşte între: a) două metale ; b) două nemetale; c) un metal şi un nemetal. 3. O legătură covalentă se stabileşte: a) între hidrogen şi sodiu ; b) între azot şi hidrogen; c) între aluminiu şi oxigen.. 4. Legăturile covalente sunt de două feluri: a) legături covalente simple si legaturi covalente duble; b) legături covalente polare şi legături covalente nepolare; c) nici un raspuns nu este corect. 5. Selectează substanțele în moleculele cărora atomii sunt uniți prin legătură ionică: a) oxid de fosfor P2O5; b)clorură de potasiu KCl; c) apă H2O

Answers

Answer 1

Answer:

1) Option A is correct.

The covalent bond is the chemical bond that is established by pooling of electrons.

2) Option B is correct.

The covalent bond is established between two non-metals.

3) Option B is correct.

A covalent bond is established between nitrogen and hydrogen.

4) Option B is correct.

Covalent bonds are of two types; polar covalent bonds and non-polar covalent bonds.

5) Option B is correct.

Select the substances in the molecules of which the atoms are united by ionic bond.

potassium chloride KCl

1) Opțiunea A este corectă.

Legătura covalentă este legătura chimică care se stabilește prin punerea în comun a electronilor.

2) Opțiunea B este corectă.

Legătura covalentă este stabilită între două nemetale.

3) Opțiunea B este corectă.

Se stabilește o legătură covalentă între azot și hidrogen.

4) Opțiunea B este corectă.

Legăturile covalente sunt de două tipuri; legături covalente polare și legături covalente nepolare.

5) Opțiunea B este corectă.

Selectați substanțele din moleculele cărora atomii sunt uniți prin legătură ionică. clorură de potasiu KCl

Explanation:

English Translation

1) The covalent bond is the chemical bond that is established: a) by pooling electrons; b) by electron transfer; c) by pooling or electron transfer.

2) The covalent bond is established between: a) two metals; b) two non-metals; c) a metal and a non-metal.

3) A covalent bond is established: a) between hydrogen and sodium; b) between nitrogen and hydrogen; c) between aluminum and oxygen.

4) Covalent bonds are of two types: a) single covalent bonds and double covalent bonds; b) polar covalent bonds and non-polar covalent bonds; c) no answer is correct.

5) Select the substances in the molecules of which the atoms are united by ionic bond: a) phosphorus oxide P2O5; b) potassium chloride KCl; c) H2O water

Solution

Covalent bonds are bonds that result from the sharing/pooling of electrons by two non-metallic atoms. When the electronegativity difference between the two atoms in a cobalent bond is substantial, a polar covalent bond results (in which the shared electrons are closer to the more electronegative atom of the pair). If the electronegativity difference isn't significant, a non-polar covalent bond ensues, in which the shared electrons are approximately equidistant from both atoms.

1) The covalent bond is the chemical bond that is established by pooling of electrons.

Already explained above.

2) The covalent bond is established between two non-metals.

Already explained too.

3) A covalent bond is established between nitrogen and hydrogen.

Of the three options, only option B contains two elements, nitrogen and hydrogen, which are both non-metals amd this satisfy the condition for the formation of a covalent bond.

4) Covalent bonds are of two types; polar covalent bonds and non-polar covalent bonds.

Already explained above.

5) Select the substances in the molecules of which the atoms are united by ionic bond.

potassium chloride KCl

Ionic bonds result from the transfer of electrons from metals (electropositive elements) to non-metals (electronegative elements). Of the 3 options provided, only potassium chloride is a coming together of a metal and a non metal.

In Romanian/In limba romana

Legăturile covalente sunt legături care rezultă din împărțirea / îmbinarea electronilor de către doi atomi nemetalici. Când diferența de electronegativitate între cei doi atomi dintr-o legătură cobalentă este substanțială, rezultă o legătură covalentă polară (în care electronii partajați sunt mai apropiați de atomul mai electronegativ al perechii). Dacă diferența de electronegativitate nu este semnificativă, apare o legătură covalentă non-polară, în care electronii partajați sunt aproximativ echidistanți de la ambii atomi.

Legăturile ionice rezultă din transferul electronilor de la metale (elemente electropozitive) la nemetalele (elemente electronegative).

Hope this Helps!!!

Sper că acest lucru vă ajută!!!!


Related Questions

How sensitive to changes in water temperature are coral reefs? To find out, measure the growth of corals in aquariums where the water temperature is controlled at different levels. Growth is measured by weighing the coral before and after the experiment.

(a) What are the explanatory and response variables?
explanatory variable:
response variable:
(b) Are they quantitative or categorical?
The explanatory variable is:
The response variable is:

Answers

Answers:

(a) The explanatory variable is the change in the temperature .

The response variable is the coral survivance.

(b) The explanatory variable is quantitative.

The response variable is categorical.

Explanation:

A quantitative variable is those that can take a range of values. In this case, the temperature may vary across a range of values associated with the survival of coral reefs.  

A categorical (also known as qualitative) variable is characterized to present finite states. In this case, the coral reefs can survive or not depending on their responses to changes in the temperature.

Response and explanatory variables are used in experimental procedure ; the explanatory and response variables are :

Measured variable - > Change in weight of coral (quantitative)

Explanatory variable - > Temperature of water. (categorical)

Explanatory variables are independent variables which causes changes to the measured variable.

Measured variable is the variable we intend to measure in an experiment. They are called dependent variables.

Quantitative variables are numerical values, weight is measured as a number. Hence, it is quantitative.

Categorical variables are labels and are used to group objects into classes. They are Non-numeric. Levels of temperature could be (high, medium, low). Hence, temperature is categorical in the experiment.

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which of the following objects have kinetic energy? check all that apply

Answers

Answer:

what are the options?

Explanation:

do you have multiple choice for this question?

Answer:

A book inside a vehicle, a running cat, and a falling meteorite.

Explanation:

I just took it

Complete the sentence indicating the number of protons and electrons in the given ion. Match the numbers in the left column to the appropriate blanks in the sentences on the right. The ion P3− has The ion P 3 − has blank protons and blank electrons. protons and The ion P 3 − has blank protons and blank electrons. electrons.
What isotope has 17 protons and 18 neutrons? Enter the name of the element followed by a hyphen and the mass number (e.g., uranium-234).
Which element does X represent in the following expression: 4120X? Enter the chemical symbol of the element. X is the element symbol . Provide Feedback Correct. Followup. All bromine atoms have 35 protons. A neutral atom also has 35 electrons. The sum of the protons and neutrons gives the mass number, . End of followup.

Answers

Answer: (Chlorine-35)

Element X is Ca

Explanation:

Number of proton plus the number of electron gives the mass number.

If you made a three-dimensional model of an atom and its nucleus, how would you represent the atom? 7th grade

Answers

Answer:

it shows the breakdown of the atom

Explanation:

it will show it molecularly


3. The exosphere is the outer layer of the
O D. thermosphere
OC. mesosphere
O A. ozone layer
O B. troposhpere
ang
AT
HHH​

Answers

Answer:

D. exosphere is the outer layer of the thermosphere

The H 2 produced in a chemical reaction is collected through water in a eudiometer. If the pressure in the eudiometer is 760.0 torr and the vapor pressure of water under the experimental conditions is 23.8 torr, what is the pressure (torr) of the H 2 gas

Answers

Answer:

the pressure (torr) of theH₂ gas is 736.2 torr

Explanation:

Given that

The H₂ gas  produced in a chemical reaction is collected through water in a eudiometer; during this process, the gas collected contains some droplets of water vapor along with these gas.

So; the total pressure in the eudiometer = Pressure in the H₂ gas  - Pressure of the water vapor

Where;

[tex]P_{Totsl}[/tex] =  total pressure in the eudiometer = 760.0 torr

[tex]P_{H_2}[/tex] = Pressure in the H₂ gas  = ???

[tex]P_{H_2O}[/tex] = Pressure in the water vapor  = 23.8 torr

Now:

[tex]P_{Totsl}[/tex] = [tex]P_{H_2}[/tex] + [tex]P_{H_2O}[/tex]

- [tex]P_{H_2}[/tex] = + [tex]P_{H_2O}[/tex] - [tex]P_{Totsl}[/tex]

[tex]P_{H_2}[/tex]  = - [tex]P_{H_2O}[/tex] + [tex]P_{Totsl}[/tex]

[tex]P_{H_2}[/tex]  =  (- 23.8 + 760) torr

[tex]P_{H_2}[/tex]  = 736.2 torr

Thus; the pressure (torr) of theH₂ gas is 736.2 torr

If the pressure in a eudiometer is 760.0 torr and the vapor pressure of water is 23.8 torr, the pressure of the H₂ gas is 736.2 torr.

A eudiometer is a laboratory device that measures the change in volume of a gas mixture following a physical or chemical change. Usually, the gas is collected over water.

According to Dalton's law of partial pressures, the sum of the sum partial pressure of the hydrogen and the partial pressure of the water is equal to the total pressure in the eudiometer.

[tex]P = pH_2 + pH_2O\\\\pH_2 = P - pH_2O = 760.0 torr - 23.8 torr = 736.2 torr[/tex]

If the pressure in a eudiometer is 760.0 torr and the vapor pressure of water is 23.8 torr, the pressure of the H₂ gas is 736.2 torr.

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A sample of copper absorbs 4.31E+1 kJ of heat, resulting in a temperature rise of 6.71E+1 °C. Determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J/g°C.

Answers

Answer: 1.67 kg

Explanation:

The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

[tex]Q=m\times c\times \Delta T[/tex]

Q = Heat absorbed=[tex]4.31\times 10^1kJ[/tex] = [tex]43100J[/tex]   (1kJ=1000J)

m= mass of substance = ?

c = specific heat capacity = [tex]0.385J/g^0C[/tex]

Change in temperature ,[tex]\Delta T=T_f-T_i=6.71\times 10^1^0C=67.1^0C[/tex]

Putting in the values, we get:

[tex]43100J=m\times 0.385J/g^0C\times 67.1^0C[/tex]

[tex]m=1670g=1.67kg[/tex]   (1kg=1000g)

Thus the mass (in kg) of the copper sample is 1.67

Sort The following iron compound by whether the cation is iron(II) or iron(III)

Answers

Answer:

Left, Left, Right, Left, Right, Right

Explanation:

Follow that order!

Consider an Al-4% Si alloy. Determine (a) if the alloy is hypoeutectic or hypereutectic, (b) the composition of the first solid to form during solidification, (c) the amounts and compositions of each phase at 578˚C, (d) the amounts and compositions of each phase at 576˚C, (e) the amounts and compositions of each microconstituent at 576˚C, and (f) the amounts and compositions of each phase at 25˚C.

Answers

Answer:

(a) Hypoeutectic

(b) Alpha solid, aluminium

(c) 70% α , 30% β

(d) 97.6% α, 2.4% β

(e) 97.6% α, 2.4% β

(f) 97% α, 3% β

Explanation:

(a) The eutectic composition for Al Si alloy is 11.7 wt% silicon, therefore, an Al-4% Si alloy is hypoeutectic

(b) For the hypoeutectic alloy, aluminium, Al, is expected to form first, such that the aluminium content is reduced till the point it gets to the eutectic proportion of 11.7 wt% silicon

(c) At  578°C we have

% α:  Al      (11 - 4)/(11 - 1) = 70% α

% L:  Si      100 - 70 = 30% β

(d) At  576°C we have

α: 99.83% Si    (99.83 - 4)/(99.83- 1.65) = 97.6% α

β: 1.65% Si (4 - 1.65)/(99.83- 1.65) = 2.4% β

(e) Primary α: 1.65% α (99.83 - 4)/(99.83 - 1.65) = 97.6% α

Eutectic 4% Si  = 100 - 97.6 = 2.4% β

(f) At 25°C we have;

α%: (99.83 - 4)/(99.83 - 1) = 97% α

β%:   100 - 97 = 3% β.

g 1. An ideal gas is confined to a container with adjustable volume. The number of moles, n, and temperature, T, are constant. By what factor will the volume change if pressure decreases by a factor of 8.5 Hint: pV

Answers

Answer:

The volume will increase by a factor of 8.5

Explanation:

In an ideal gas, the volume is inversely proportional to the pressure. This means that the volume will decrease when the pressure increases and vice versa.

Let  the initial volume be v1, and the initial pressure p1.

the final pressure is decreased by a factor of 8.5, i.e

p2 = p1/8.5 = 0.12p1

using p1v1 = p2v2

v2 = (p1/p2)v1

v2 = (p1/0.12p1)v1

v2 = 8.5v1

This means that the final pressure increases by a factor of 8.5

Answer:

Increases by a factor of 8.5

Explanation:

Hello,

In this case, with the given data, we can apply the Boyle's law in order to understand the pressure-volume behavior as an inversely proportional relationship:

[tex]P_1V_1=P_2V_2[/tex]

Thus, for the given pressure decrease we have:

[tex]P_2=\frac{P_1}{8.5}[/tex]

So the volume changes by:

[tex]V_2=\frac{P_1V_1}{\frac{P_1}{8.5} } \\\\V_2=8.5V_1[/tex]

Therefore, it increases by a factor of 8.5.

Regards.

What is the color of litmus solution in sodium hydroxide?

Answers

Answer:

Sodium Hydroxide turns blue litmus red .

Suppose there is 0.63 g of HNO3 per 100 mL of a particular solution. What is the concentration of the HNO3 solution in moles per liter?

Answers

Answer:

There are 0.09996826 moles per liter of the solution.

Explanation:

Molar mass of HNO3: 63.02

Convert grams to moles

0.63 grams/ 63.02= 0.009996826

Convert mL to L and place under moles (mol/L)

100mL=0.1 L

0.009996826/0.1= 0.09996826 mol/L

The concentration of the HNO₃ solution is 10⁻¹ moles per liter.

What is Molar Concentration ?

Molar Concentration is known as Molarity. It is the number of moles of solute present in per liter of the solution.

Molar concentration in terms of Molecular weight

C = [tex]\frac{m}{V} \times \frac{1}{M.W}[/tex]

where,

C is the molar concentration in mol/L

m is the mass or weight of solute in grams

V is volume of solution in liters

M.W is the molecular weight in g/mol

Molar concentration of HNO₃ = [tex]\frac{\text{Mass of}\ HNO_3}{\text{Liter of solution}} \times \frac{1}{\text{Molecular weight of}\ HNO_3}[/tex]

Molecular weight of HNO₃ = Atomic weight of H + Atomic weight of N + 3 (Atomic weight of O)

                                  = 1 + 14 + 3 (16)

                                  = 15 + 48

                                  = 63 g/mol

Convert mL into L

1 mL = 0.001 L

100 mL = 100 × 0.001

            = 0.1 L

Now, put the value in above formula we get

Molar concentration of HNO₃ = [tex]\frac{\text{Mass of}\ HNO_3 / \text{Liter of solution}}{\text{Molar mass of}\ HNO_3}[/tex]

                                                   =  [tex]\frac{0.63\ g / 0.1\ L}{63\ g/mol}[/tex]

                                                   = [tex]\frac{6.3}{63}[/tex]

                                                  = 0.1

                                                   = 10⁻¹ moles per liter

Thus, we can say that 10⁻¹ moles per liter is the concentration of the HNO₃ solution.

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The conversion of methyl isonitrile to acetonitrile in the gas phase at 250 °C CH3CN(g) is first order in CH3NC with a rate constant of 3.00×10^-3 s-1. If the initial concentration of CH3NC is 5.45×10^-2 M, the concentration of CH3NC will be 1.56×10^-2 M after_____________ s have passed.

Answers

Answer: The concentration of [tex]CH_3NC[/tex] will be [tex]1.56\times 10^{-2}M[/tex] after 416 seconds have passed.

Explanation:

Expression for rate law for first order kinetics is given by:

[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]

where,

k = rate constant = [tex]3.00\times 10^{-3}s^{-1}[/tex]

t = age of sample = ?

a = let initial amount of the reactant = [tex]5.45\times 10^{-2}M[/tex]

a - x = amount left after decay process = [tex]1.56\times 10^{-2}M[/tex]

[tex]t=\frac{2.303}{3.00\times 10^{-3}}\log\frac{5.45\times 10^{-2}}{1.56\times 10^{-2}}[/tex]

[tex]t=416s[/tex]

The concentration of [tex]CH_3NC[/tex] will be [tex]1.56\times 10^{-2}M[/tex] after 416 seconds have passed.

if two atoms are bonded to a central atom with no lone pairs , how will they be arranged?

Answers

Most likely the geometric form of the molecule will be linear.
Explanation:
One possibility is the central atom being an atom with two valance electrons. This will create a liner molecule with no lone pairs of electrons
Another possibility is a central atom being an atom with four valance electrons. If the two atoms each require two bonds like oxygen the result will be a linear molecule with no lone pairs of electrons.

Can the pH scale be utilized for all acids (Arrhenius, Bronsted-Lowery, and Lewis)? Give examples of substances from each definition category that can/cannot use the pH scale and explain your reasoning.

Answers

Explanation:

Before proceeding to answering the questions, let us go over some definitions.

pH scale: The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic.

pH stands for Potential of Hydrogen. It refers to the hydrogen ion concentration in a solution.

The keywords being; Hydrogen Ion concentration.

A Bronsted-Lowry acid is a chemical species that donates one or more hydrogen ions in a reaction.

A Lewis acid is  any substance that can accept a pair of nonbonding electrons. It is an electron pair acceptor.

An Arrhenius acid is a substance that dissociates in water to form hydrogen ions or protons.

Based on the definitions of given above, it is obseved that both Bronsted lowry and arrhenius acids deals with hydrogen ions. Hence both of this acids can be measured using the pH scale. The  lewis acid on the other hand do not necessarily contain hydrogen ions, hence the pH scale cannot be utilized for it.

Examples includes;

Arrhenius acid; Nitric Acid – HNO3 etc

Lewis acid; boron trifluoride (BF3) and aluminum fluoride (AlF3) etc

Bronsted lowry acid; HCl etc

Many computer chips are manufactured from silicon , which occurs in nature as SiO2. WhenSiO 2 is heated to melting , it reacts with solid carbon to form liquid silicon and carbon monoxide gas. In an industrial preparation of silicon, 155.8 kg of SiO2 reacts with 78.3 kg of carbon to produce 66.1 kg of silicon. Determine the limiting reactant, theoretical yield, and percent yield for the reaction.

Answers

Answer:

In the given case, SiO2 is the limiting reactant, 71.72 Kg is the theoretical yield, and 90.8 percent is the experimental yield.

Explanation:

A reactant that completely gets used up in a chemical reaction, and it limits the concentration of product, which can be produced is termed as a limiting reactant. The maximum concentration of product that can get generated from the limiting reactant is termed as the theoretical yield.  

Based on the given question, the balanced chemical reaction is:  

SiO₂ + 2C ⇒ Si + 2CO

Now the mole ratio of SiO₂: C = 1: 2

Based on the given information, the mass of SiO₂ is 155.8 Kg. The no. of moles can be calculated by using the formula, n = weight/molecular mass.  

The molecular mass of SiO₂ is 60.08 gram per mole. By putting the values we get,  

n = 155.8 × 10³ grams / 60.08 grams/mol

n = 2.59 × 10³ moles

The weight of Carbon given is 78.3 Kg or 78.3 × 10³ grams, the molecular mass of C is 12 gram per mole. Similarly, the moles of C will be,  

n = 78.3 × 10³ grams / 12 g/mol

n = 6.52 × 10³ moles

The experimental molar ratio of SiO₂: C is,  

= 2.59 × 10³: 6.52 × 10³

= 2.59: 6.52 = 1: 2.5

Hence, it is clear that carbon in the given case is present in excess amount, therefore, SiO₂ is a limiting reactant.  

With the help of the balanced equation, the molar ratio of SiO₂: Si is 1: 1. As SiO₂ is the limiting reactant, therefore, theoretical yield of the reaction will be determined by SiO₂.  

As calculated, the moles of SiO₂ used is 2.59 × 10³

Hence, the moles of Si produced in the given reaction is 2.59 × 10³.  

Now the mass of Si produced theoretically can be determined by using the formula, moles = weight/molar mass. The molar mass of Si is 28.08 gram per mole. Now putting the values we get,  

Weight = 2.59 × 10³ moles × 28.08 gram per mole

Weight = 72.72 × 10³ grams or 72.72 Kg

The theoretical yield of Si is 72.72 Kg, however, the experimental yield is 66.1 Kg. Therefore, the percent yield for the reaction will be,  

= Experimental yield / Theoretical yield × 100 %

= 66.1 Kg / 72.72 Kg × 100%

= 90.8 %

Combustion analysis of a 13.42-g sample of an unknown organic compound (which contains only carbon, hydrogen, and oxygen) produced 36.86 g CO2 and 10.06 g H2O. The molar mass of the compound is 288.38 g/mol . Part A Find the molecular formula of the unknown compound. Express your answer as a chemical formula.

Answers

Answer:

[tex]C_{18}H_{24}O_3[/tex]

Explanation:

Hello,

In this case, combustion analyses help us to determine the empirical formula of a compound via the quantification of the released carbon dioxide and water since the law of conservation of mass is leveraged to attain it. In such a way, as 36.86 g of carbon dioxide were obtained, this directly represents the mass of carbon present in the sample, thus, we first compute the moles of carbon:

[tex]n_{C}=36.86gCO_2*\frac{1molCO_2}{44gCO_2} *\frac{1molC}{1molCO_2} =0.838molC[/tex]

Then, into the water one could find the moles of hydrogen:

[tex]n_{H_2O}=10.06gH_2O*\frac{1molH_2O}{18gH_2O}*\frac{2molH}{1molH_2O} =1.12molH[/tex]

Now, we compute the moles of oxygen by firstly computing the mass of oxygen:

[tex]m_{O}=13.42g-36.86gCO_2*\frac{12gC}{44gCO_2} -10.06 gH_2O*\frac{2gH}{18gH_2O} =2.25gO[/tex]

[tex]n_O=2.25gO*\frac{1molO}{16gO} =0.141molO[/tex]

Then, we have the mole ratio:

[tex]C_{0.838}H_{1.12}O_{0.141}\rightarrow C_6H_8O[/tex]

Whose molar mass is 12x6+1x8+16=96 g/mol, but the whole compound molar mass is 288.38, the factor is 288.38/96 =3, Therefore the formula:

[tex]C_{18}H_{24}O_3[/tex]

Regards.

Answer:

Molecular mass = [tex]C_{6} H_{8} O_{16}[/tex]

Explanation:

[tex](\frac{36.86gCO_{2} }{44g/molCO_{2} })[/tex] [tex](\frac{10.06gH_{2}O}{18g/molH_{2}O} )[/tex]

(0.8377mol of CO2) (0.556 mol of H2O)

mole ratio of CO2 to H2O = 1.5 : 1 ≅ 3 : 2

[tex](CO_{2} )_{3} , (H_{2} O)_{2}[/tex]

⇒ [tex](C_{3} H_{4} O_{8} )_{x}[/tex] = 288.38

(12 × 3 + 1 × 4 + 16 × 8)x = 288.38

168x = 288.38

x = 1.71 ≅ 2

∴ Molecular mass = [tex]C_{6} H_{8} O_{16}[/tex]

4. Alex is a soil specialist and he sells manure best suited for wheat. He goes to a village where farmers are
planning to sow wheat which grows best in clayey and loamy soil. He tests the soil sample and finds
that the soil is more suitable for the growth of cotton rather than wheat. He tells the villagers about
this despite knowing that they will not buy his manure.

(a) Why is clayey-loamy soil preferred for growing wheat?

(b) Which value is shown by Alex?

Please answer the question fast

Answers

Answer:

Explanation:

1) Clayey-loamy soil tends to be excellent at retaining water which is critical for proper growth of wheat thus this kind of soil is preferred.

2) Alex is showing honesty as he informing the villagers about the actual truth and reality (he is not basing his answers on judgements rather he is basing it on scientific knowledge and being honest about it)

Calculate the final temperature of 12.0 g of Argon (considered as an ideal gas) that is expanded reversibly and adiabatically from V1 = 1.00 dm3 at T1 = 273.15 K to V2 = 3.00 dm3 . CV,m(Ar) = (3/2) * R.

Answers

Answer:

Explanation:

For adiabatic change the expression is  

= [tex]PV^\gamma=constant[/tex]

[tex]=(\frac{RT}{V})V^\gamma = constant[/tex]

[tex]=TV^{\gamma-1} = constant[/tex]

[tex]=T_1V_1^{\gamma-1} =[/tex][tex]=T_2V_2^{\gamma-1}[/tex]

for Argon γ = 1.67

273.15 x 1 = T₂ x [tex]3^{1.67-1}[/tex]

T₂ = 273.15 / [tex]3^{0.67}[/tex]

= 273.15/ 2.0877

= 130.83 K.


A substance is considered to have a smaller surface area when...

A. it is a fine powder
B. it is in large chunks
C. you have a small amount of
the substance
D. you have a large amount of E. the substance

Answers

Answer: C you have a small amount of substance

Assign priorities in the following set of substituents according to Cahn-Ingold-Prelog rules. -NH2 -CH2OH -OH -Br A B C D (Provide your ranking through a string like abcd, starting with the one with the highest priority. Your answer does not need to be capitalized.)

Answers

Complete Question

The complete question is shown on the first uploaded image

Answer:

[tex]-SH \ \ A[/tex]

[tex]-NH_2 \ \ B[/tex]

[tex]-COOH \ \ C[/tex]

[tex]-CH_3 \ \ D[/tex]

Explanation:

Now to correctly assign priorities in the following set of substituents we need to consider the molecular weight of the atom that is been directly attached to  the carbon bond

Now an atom with a higher molecular weight will imply that the substituent will have the the highest priority

So  S (32.065 u)with a the highest molecular weight implies that -SH has the highest priority

Next is   N with molecular weight(14.0067 u) implies that -[tex]NH_2[/tex] will  have the next priority

Next is   O with molecular weight(15.999 u) implies that [tex]-COOH[/tex] will  have the next priority

The Last is  H with molecular weight(1.00784 u) implies that  [tex]-CH_3[/tex] will  have the next priority

A salt contains a compound containing a metal and a nonmetal. This is an
compound. *

A.molecular
B.covalent
C.Tonic
D.None of the above

Answers

Answer:

Option C. Ionic

Explanation:

Ionic bond is formed between a metal and a non metal.

Ionic bond occurs when there is a transfer of electron(s) from a metallic atom to a non metallic atom.

g + In a coffee-cup calorimeter, when 3.25 g of NaOH is dissolved in 50.00 g of water initially at 22.0 oC, the temperature of the solution increases to 24.8 oC. Calculate the q of the reaction in kJ/mol of NaOH. Assume that the specific heat of the solution is 4.184 J/g oC, and that there is no other heat transfer than that of the solution process itself.

Answers

Answer:

THE STANDARD HEAT OF SOLUTION OF SODIUM HYDROXIDE IN WATER IS -7.68 KJ PER MOLE.

Explanation:

Variables:

Mass of NaOH = 3.25 g

Mass of water = 50 g

Initial temperature of water = 22°C = 22 + 273 K = 295 K

Final temperature of the reaction mixture = 24.8 °C = 24.8 + 273 K = 297.8 K

Assuming that:

1. specific heat of water = 4.184 J/g °C

2. total mass of the reaction mixture = 50 g + 3.25 g = 53.25 g

3. the rise in temperature = (297.8 K - 295 K ) = 2.8 K

4. Molar mass of sodium hydroxide = ( 23 + 16 + 1) = 40 g/mol

5. number of mole of sodium hydroxide = mass / molar mass

n = 3.25 g / 40 g/mol

n = 0.08125 moles

The rise in temperature for the reaction mixture produces how much of heat:

Heat = mass * specific heat * change in temperature

Heat = 53.25 * 4.184  * 2.8

Heat = 623.8344 J of heat.

Equation of reaction:

NaOH + H2O -------> NaOH + H2O + Heat

This is not a reaction but a dissolution as sodium hydroxide is very soluble in water and this reaction is exothermic where heat is given off.

So since 3.25 g having 0.08125 moles produces 623.8344 J of heat, 1 mole of the sodium hydroxide used will produce:

0.08125 mole of sodium hydroxide = 623.8344 J of heat

1 mole of sodium hydroxide = ( 623.8344 / 0.08125 J of heat

= 7677.96 J of heat per mole of sodium hydroxide.

= 7.68 kJ of heat

So therefore, the standard heat of solution of sodium hydroxide in water is -7.68 kJ of heat since its an exothermic reaction.

How many hydrogen atom are present in 1.53 g of water

Answers

Answer:

[tex]=1.02x10^{23} atoms\ H[/tex]

Explanation:

Hello,

In this case, for water, whose molar mass is 18 g/mol, we can find two moles of hydrogen in one mole of water, therefore, for us compute the atoms, we should also use the Avogadro's number as shown below:

[tex]=1.53gH_2O*\frac{1molH_2O}{18gH_2O}*\frac{2molH}{1molH_2O} *\frac{6.022x10^{23}atoms\ H}{1molH} \\\\=1.02x10^{23} atoms\ H[/tex]

Regards.

which two compounds are structural isomers of each other

Answers

Answer:

Explanation:

Structural isomer is a type of isomer in which molecules with the same molecular formula have different bonding patterns and atomic organization.

For example Pentan-1-ol, pentan-2-ol, and pentan-3-ol are structural isomers that exhibit position isomerism.

Cyclohexane and hex-1-ene are examples of functional group structural isomers.

(i) 1s 2 2s 2 2p 6 3s 1 (ii) 1s 2 2s 2 2p 6 3s 2 (iii) 1s 2 2s 2 2p 6 3s 2 3p 1 (iv) 1s 2 2s 2 2p 6 3s 2 3p 4 (v) 1s 2 2s 2 2p 6 3s 2 3p 5 The electron configuration of the atom that is expected to have a positive electron affinity is ________.

Answers

Answer:

 (V) 1s 2 2s 2 2p 6 3s 2 3p 5

Explanation:

Electron Affinity can be defined as the energy associated with a neutral atom, when an electron is added to form a negative ion.

1s 2 2s 2 2p 6 3s 2 3p 5 , is the electronic configuration of Chlorine.

The electron affinity is positive because it is an exorthermic reaction, meaning that, energy was released during the addition of an electron to the atom.

Cl (g)  +  e-   ------->  Cl- (g)    = -349KJ/mol


Write the identity of the missing nucleus for the following nuclear decay reaction:
232 Th 228Ra+?
90
88
low.
Express your answer as a particle.
View Available Hints
Hint 1. Determine the missing mass number
1
Hint 2. Determine the missing atomic number
Hint 3. Determine the symbol of the new nucleus
?

Answers

Answer:

Alpha decay: 4 2He

Explanation:

Considering the equation given in the question, we can see that the mass number of daughter nuclei (228 88Ra) reduce by 4 and the atomic number reduce by 2 when compared with the parent nucleus (232 90Th). This simply indicates that the parent nucleus is undergoing alpha decay.

Therefore, the missing nucleus is

4 2He i.e alpha decay.

Please see attachment photo for further details.

write briefly how oxygen gas is prepared in the industry​

Answers

by fractional distillation of liquefied air or the use of zeolites to remove carbon dioxide and nitrogen from air or the electrolysis of water

Two chemicals A and B are combined to form a chemical C. The rate, or velocity, of the reaction is proportional to the product of the instantaneous amounts of A and B not converted to chemical C. Initially, there are 40 grams of A and 50 grams of B, and for each gram of B, 2 grams of A is used. It is observed that 25 grams of C is formed in 8 minutes. How much (in grams) is formed in 16 minutes

Answers

Answer: 45. 78 g  is formed in 16 minutes.

Explanation:

Let [tex]A_{o} =40 g[/tex] and [tex]B_{o} =50 g[/tex]

we know that [tex]\alpha =A_{o}\frac{M+N}{M}\, and \, \beta =B_{o}\frac{M+N}{N}[/tex]

According to the question to create [tex]x[/tex] part of the chemical C we will need 2 part of A and one part of B.

Therefore, M = 2 and N = 1.

Now, we can easily solve  for the value of α and β.

[tex]\alpha =40\frac{2+1}{2}=60\\\\\, and \, \beta =50\frac{2+1}{1}=150[/tex]

Now, the differential equation must be: [tex]\frac{dX}{dt}=k\left ( \alpha -X \right )\left ( \beta -X \right )[/tex]

I separate the variable and solve the equation

[tex]\int \frac{dx}{\left ( 60-x \right )\left ( 150-x \right )}=\int k\, dt[/tex]

[tex]ln\frac{150-x}{60-x}=90kt+C_{1}[/tex]

By using [tex]X(0) =0[/tex],

[tex]\frac{150-x}{60-x}=Ce^{90k_{o}},C=\frac{5}{2}[/tex]

and using [tex]X (8)=25[/tex] and solving for the value of 'k'

[tex]\Rightarrow \frac{150-25}{60-25}=\frac{5}{2}e^{450k}\\\\\Rightarrow 3.6\times \frac{2}{5}=e^{450k}\\\\\Rightarrow 1.4=e^{450k}[/tex]

Taking 'ln' both side, we get

[tex]\Rightarrow k=7.4716\times 10^{-4}[/tex]

We obtain:[tex]X(t)=\frac{60Ce^{90kt}-150}{Ce^{90kt}-1}[/tex]

Now, for the 16 min

[tex]\Rightarrow X(16)=\frac{150e^{1.07559}-150}{2.5e^{1.0759}-1}[/tex]

[tex]\Rightarrow X(16)=\frac{439.7583-150}{7.3293-1}\\\\\Rightarrow X(16)=\frac{289.7583}{6.3293}[/tex]

[tex]\Rightarrow X(16)=45.78 g[/tex]

What is mass per unit volume called?

Answers

Answer:

The correct answer is Density

Explanation:

Hope this helps you

Answer:density

Explanation:

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