Answer:
Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles.
1.83 moles K (6.022 x 10^23 atoms / mole ) = 1.10 x 10^24 atoms K
Explanation:
1.83 moles K (6.022 x 10^23 atoms / mole ) = 1.10 x 10^24 atoms
In the reaction of silver nitrate and sodium chloride to produce solid silver chloride, sodium ions and nitrate ions are ________. spectator ions gases solvents liquids molecules
Answer: spectator ions
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.
The total ionic chemical equation is:
[tex]Ag^+(aq)+NO_3^-(aq)+Na^+(aq)+Cl^-(aq)\rightarrow AgCl+Na^+(aq)+NO_3^-(aq)[/tex]
The ions which are present on both the sides of the equation are sodium and nitrate ions which are called as spectator ions and hence are not involved in net ionic equation.
Sodium (Na) reacts with chlorine gas to form the ionic compound NaCl. Which of the following statements is true? A The reaction leaves each atom more unstable. B Sodium gains electrons from the chlorine to form the sodium ion. C Sodium ions are anions in the ionic bond. D By reacting, each atom fills its outer energy level with electrons.
Answer:
D
Explanation:
When Na and Cl react, Na gives up one electron to Cl to fill both their valence electron shells. Both atoms are more stable, chlorine gains the electrons, and chloride is the anion.
Answer: D. After reacting, each ion has a stable octet. (For Gradpoint)
Explanation:
This increase in blood pHpH due to hyperventilation disrupts O2O2 transport by causing the deprotonation of various residues of the hemoglobin protein. With less O2O2 reaching the brain, an individual who is hyperventilating may faint. Because the brain needs O2O2 to produce ATP, the brain temporarily shuts down the one function that demands the most ATP—consciousness. Shutting down consciousness conserves energy and allows the brain to devote its resources to maintaining essential life support functions, such as breathing. When O2O2 transport regains its efficiency, the individual regains consciousness. How would rebreathing exhaled air from a paper bag prevent an individual who is hyperventilating from fainting?
The question is incomplete as it does not have the options which has been provided in the attachment.
Answer:
1. sudden decrease
2. Respiratory alkalosis
Explanation:
Hyperventilation is a condition caused by the excess removal of the CO₂ from the blood which leads to the decrease in the pCO₂ of the arteries.
This decrease can cause fainting and death of the individual due to the malfunctioning of the body parts, especially the brain.
The decrease in the CO₂ amount of the blood causes the formation of bicarbonate and H⁺ ions which leads to respiratory alkalosis.
Therefore the selected options are correct.
). In a titration, a student obtained an average titre value of 3.9 cm3 of 0.3 M HCl. If the volume of Na2CO3 solution used is 10 cm3 and the indicator used is phenolphthalein, calculate; (i). the molarity of the Na2CO3 (4 marks) (ii). the mass concentration of the Na2 theCO3. (4 marks)
Answer:
I) 0.0585 M
ii)6.2 g dm-3
Explanation:
The reaction equation is given as;
Na2CO3(aq) +2HCl(aq)------> 2NaCl(aq) + CO2(g) +H2O(l)
Concentration of acid CA= 0.3 M
Volume of acid VA= 3.9 cm^3
Concentration of base CB= the unknown
Volume of base VB= 10 cm^3
Number of moles of acid NA= 2
Number of moles of base NB= 1
From;
CAVA/CBVB= NA/NB
CAVANB=CBVBNA
CB= CAVANB/VBNA
substituting values;
CB= 0.3 × 3.9 × 1/ 10.0 × 2
CB= 0.0585 M
ii) mass concentration= molar concentration × molar mass
Molar mass of Na2CO3= 106 gmol-1
Mass concentration= 0.0585 × 106 = 6.2 g dm-3
A mixture of krypton and argon gases, at a total pressure of 733 mm Hg, contains 3.97 grams of krypton and 6.34 grams of argon. What is the partial pressure of each gas in the mixture?
Answer:
Partial pressure of krypton= 167.12 mmHg
Partial pressure of argon = 565.88 mmHg
Explanation:
The partial pressure of a gas in a mixture of gasses is equal to the total pressure multiplied (Pt) by the mole fraction of the gas (X):
P= X Pt
The total pressure is Pt= 733 mmHg
The mole fraction is given by the following:
X = number of moles of gas/ total number of moles
For krypton (Kr) , the molecular weight is 83.8 g/mol and we calculate the number of moles by dividing the mass into the molecular weight as follows:
moles of Kr = 3.97 g/(83.8 g/mol)= 0.047 moles
For argon (Ar), the molesular weight is 39.9 g/mol, so we calculate the number of moles as follows:
moles of Ar = 6.34 g/(39.9 g/mol)= 0.159
Now, we calculate the total number of moles (nt):
nt= moles of Kr + moles of Ar = 0.047 moles + 0.159 moles = 0.206 moles
The mole fraction of each gas is now calculated:
X(Kr)= moles of Kr/nt = 0.047 moles/0.206 = 0.228
X(Ar)= moles of Ar/nt = 0.159 moles/0.206 = 0.772
Finally, with the mole fractions and the total pressure we calculate the partial pressure of each gas as follows:
P(Kr) = X(Kr) x Pt = 0.228 x 733 mmHg= 167.12 mmHg
P(Ar) = X(Ar) x Pt = 0.772 x 733 mmHg= 565.88 mmHg
In 1782 a French chemist named ________ proposed a systematic nomenclature for naming chemical compounds.
Answer:
Louis-Bernard Guyton De Morveau
Explanation:
He is who proposed the first systematic nomenclature for naming chemical compounds.
A 10.17-g sample of solid sodium bicarbonate (the active ingredient in baking soda) completely decomposes into solid sodium hydroxide and carbon dioxide gas when heated. After the sodium hydroxide cools, it has a mass of 4.84 g. According to the law of conservation of mass, what mass of carbon dioxide must have been formed?
Answer:
5.33 g
Explanation:
Let's consider the balanced reaction for the complete decomposition of solid sodium bicarbonate to form solid sodium hydroxide and carbon dioxide gas when heated.
NaHCO₃(s) → NaOH(s) + CO₂(g)
According to Lavoisier's law of conservation of mass, the sum of the masses of the reactants is equal to the sum of the masses of the products. Then,
m(NaHCO₃) = m(NaOH) + m(CO₂)
m(CO₂) = m(NaHCO₃) - m(NaOH)
m(CO₂) = 10.17 g - 4.84 g
m(CO₂) = 5.33 g
Which energy conversion occurs in an operating voltaic cell? A) electrical energy to nuclear energy B) chemical energy to electrical energy C) chemical energy to nuclear energy D) electrical energy to chemical energy
Answer:
B) chemical energy to electrical energy
Explanation:
The correct option is B.
Which process occurs in a voltaic cell?A voltaic cell is an electrochemical cell that uses a chemical reaction to produce electrical energy. The important parts of a voltaic cell: The anode is an electrode where oxidation occurs. The cathode is an electrode where reduction occurs.
What kind of energy is converted in a galvanic cell?A galvanic cell is an electrochemical cell that converts the free energy of a chemical process into electrical energy. A photogalvanic cell is one that generates species photochemically which react resulting in an electrical current through an external circuit.
Learn more about energy conversion here https://brainly.com/question/961052
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Examine the reaction equation. CH4 + O2 →H2O + CO2 What coefficients will balance the equation? A) 2, 3, 2, 2 B) 1, 3, 2, 1 C) 1, 2, 2, 1 D) 1, 1, 1, 1
Answer:
B
Explanation:
CH4 + O2 →H2O + CO2
Left side
C = 1
H = 4
O = 2
Right side
C = 1
H = 2
O = 3
So find common denominator in this case would be 6 O
CH4 + 3O2 →2H2O + CO2
Left side
C = 1
H = 4
O = 6
Right side
C = 1
H = 4
O = 6
Answer:
[tex]\huge \boxed{\mathrm{C) \ 1, 2,2,1}}[/tex]
[tex]\rule[225]{225}{2}[/tex]
Explanation:
[tex]\sf CH_4+ O_2 \Rightarrow CO_2 + H_2O[/tex]
Balancing the Hydrogen atoms on the right side,
[tex]\sf CH_4+ O_2 \Rightarrow CO_2 +2 H_2O[/tex]
Balancing the Oxygen atoms on the left side,
[tex]\sf CH_4+ 2O_2 \Rightarrow CO_2 +2 H_2O[/tex]
[tex]\rule[225]{225}{2}[/tex]
Maybelline Cousteau’s backup oxygen tank reads 650 torr while on her boat, where the temperature is 27 degrees C. When she dives down to the bottom of an unexplored methane lake on a recently-discovered moon of Neptune, the temperature will drop down to –183 degrees C. What will the pressure in her backup tank be at that temperature?
Answer: 180torr
Explanation:
Using P1VI/T1= P2V2/T2
where
p1= 650 torr
p2=??
T1= 27°C = 27°C + 273= 300K
T2= -183°C= -183°C +273=90K
V1= V2 ie volume is constant
SOLUTION
1 torr= 1mmHg
P1VI/T1= P2V2/T2, where V1=V2
= P1/TI= P2/T2
600/300=P2/90
P2= 600X90/300= 180 torr
Calculate the theoretical yield in moles of magnesium chloride when 37 grams of Mg(s) react with 38 grams of HCl(aq).Write the answer using 2 decimal places and do not use scientific notation.
Answer:
The correct answer is 0.52 moles.
Explanation:
Based on the given question, 37 grams of magnesium reacts with 38 grams of HCl to produce MgCl2 or magnesium chloride. The reaction is:
Mg (s) + 2HCl (aq) ⇒ MgCl2 (aq) + H2 (g)
There is a need to find the theoretical yield in moles of MgCl2. The formula for calculating the no. or moles is mass/molar mass. Therefore, moles of magnesium is 37/24 = 1.54 and moles of HCl will be 38/36.5 = 1.04.
From the reaction it is clear that one mole of magnesium reacts with two moles of HCl, as lesser quantity of HCl is present in the given case, therefore, HCl will be the limiting reagent.
Now theoretical moles of magnesium chloride will be,
= moles of HCl / 2
= 1.04 / 2
= 0.52 moles
Select all the correct answers.
What are three disadvantages of making and using plastic?
a. it pollutes the land and water
b. it requires cutting down trees from raw materials
c. it takes an incredibly long time to break down
d. it freely conducts heat and electricity
f. it isn't easy to recycle
Answer:
it is either a or c because they make the most sense
which option describes energy being released as heat?
A- a Child shivering in the cold
B- Lions Sleeping after a big meal
C- A surfer on a Surfboard
D- A Baby Bird eating a Worm
Answer:
a
Explanation:
A child shivering gives off energy to transfer that energy into heat
Answer:
A
Explanation:
An experimental procedure says to accurately weigh approximately 1 g of substance an analytical balance. Which of the following measurements are consistent with these instruction select all that apply a 1.0456 g B 1.0 g C 0.9811 g D1 gram 1.01 g E .99
Answer:
B 1.0 g
Explanation:
Hello,
In this case, by means of the significant figures we can see that 1 g has one significant figure only, for that reason, among the options, we should select one having the closest value to it, for that reason, the correct answer should be B 1.0 g as the measurement indicates the desired value.
Best regards.
A 5.000 g of Compound X with molecular formula C3H4 are burned in a constant-pressure calorimeter containing 15.00 kg of water at 25 °C. The temperature of the water is observed to rise by 3.688 °C. (You may assume all the heat released by the reaction is absorbed by the water, and none by the calorimeter itself.) Calculate the standard heat of formation of Compound X at 25 °C. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer:
THE STANDARD HEAT OF FORMATION FOR C3H8 IS 9.59 KJ/MOL.
Explanation:
Mass = 5 g of C3H4
Mass of water = 15 kg
Initial temperature of water = 25 C = 25 + 273 K = 298 K
Final temperature of water = 3.688 C = 3.688 + 273 K = 276.688 K
We may make the assumptions that:
1. the specific heat of water = 4.2 J/Kg K
2. total mass of the reaction mixture = 15 kg of water + 5 g of C3H8
= 15.005 Kg
Temperature change = 298 - 276.688 = 21.312 K
heat change for the reaction
Heat = mass * specific heat * change in temperture
Heat = 15.005 * 4.2 * 21.312
Heat = 1343.10 J
EQUATION
C3H8 + 5O2 -> 3CO2 + 4H2O + heat
Number of mole = mass / molar mass
Molar mass of HCl = 36.5 g/mol
Number of mole = 5 g/ 36.5 g/mol
Number of mole = 0.14 moles
5 g of C3H8 produces 1343.10 J of heat
0.14 mole of C3H8 produces 1343.10 J
1 mole of C3H8 will produce 1343.10 / 0.14 J of heat
= 9593.57 J
= 9.59 kJ of heat.
The standard heat of formation for C3H8 is 9.59 kJ/mol.
An analytical chemist is titrating 60.5mL of a 0.8700M solution of benzoic acid HC6H5CO2 with a 0.3600M solution of KOH . The pKa of benzoic acid is 4.20 . Calculate the pH of the acid solution after the chemist has added 172.mL of the KOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of KOH solution added. Round your answer to 2 decimal places.
Answer:
The correct answer is 12.6.
Explanation:
The formation of benzoate takes place when potassium hydroxide reacts with benzoic acid, due to the presence of a weak acid and its conjugated base the solution will act as a buffer. In the given question, the molarity of benzoic acid given is 0.8700 M and its volume is 60.5 ml. Therefore, the moles of benzoic acid will be,
Moles = molarity * volume of solution
= 0.8700 M * 60.5 ml = 52.365 m mol or 0.052365 moles
On the other hand, the molarity of KOH given is 0.3600 M and the volume given is 172 ml. Therefore, the moles of KOH added will be,
Moles = 0.3600 * 172 = 61.92 m moles or 0.06192 moles
Out of this 61.92 m mol, only 52.365 m mol of KOH will react with the benzoic acid. The moles of KOH, which remain unreactive is,
61.92 m moles - 52.365 m moles = 9.285 m moles or 0.009285 moles
The formula for calculating molarity is number of moles / volume of solution in liters
The total volume of the solution is 172 ml + 60.5 ml = 232.5 ml or 0.2325 L
The molarity of KOH will be,
Molarity = 0.009285 moles / 0.2325 L = 0.0395 M
The dissociation of KOH takes place completely to produce hydroxide ion.
pOH = -log[0.0395] = 1.4
pH + pOH = 14
pH = 14 - 1.4 = 12.6
Potatoes can be peeled commercially by soaking them in a 3M to 6M solution of sodium hydroxide, then removing the skins by spraying them with water. If titration of 12.00 mL of the sodium hydroxide requires 30.6 mL of 1.65 M HCl solution, what is the concentration of NaOH used in potato peeling?
Answer:
4.21 M
Explanation:
Step 1: Write the balanced equation
NaOH + HCl ⇒ NaCl + H₂O
Step 2: Calculate the reacting moles of HCl
30.6 mL of 1.65 M HCl reacted. The reacting moles of HCl are:
[tex]0.0306 L \times \frac{1.65mol}{L} = 0.0505 mol[/tex]
Step 3: Calculate the reacting moles of NaOH
The molar ratio of NaOH to HCl is 1:1. The reacting moles of NaOH are 1/1 × 0.0505 mol = 0.0505 mol.
Step 4: Calculate the molar concentration of NaOH
0.0505 moles of NaOH are in 12.00 mL. The molar concentration of NaOH is:
[tex]M = \frac{0.0505 mol}{0.01200L} = 4.21 M[/tex]
A flexible container at an initial volume of 6.13 L contains 6.51 mol of gas. More gas is then added to the container until it reaches a final volume of 13.3 L. Assuming the pressure and temperature of the gas remain constant, calculate the number of moles of gas added to the container.
Answer:
7.61 moles
Explanation:
Hello, we'll first of all get the required data from the question to enable us find the best approach to the question.
Data;
Initial volume (V1) = 6.13L
Initial number of moles (n1) = 6.51mol
Final volume (V2) = 13.3L
Final number of moles = ?
To solve this question, we'll use Avogadro's law which states that the number of moles of a fixed mass of gas is directly proportional to its volume provided that temperature and pressure remains constant.
Mathematically,
n = kV, k = n / V
n1 / V1 = n2 / V2 = n3 / V3 =..........=Nx / Vx
n1 / V1 = n2 / V2
Substitute the values into the above equation
6.51 / 6.13 = n2 / 13.3
n2 = (6.51 × 13.3) / 6.13
n2 = 14.12moles
The final mole of the gas is equal to 14.12mol
To find the number of moles added to the system, we'll subtract the initial mole from the final mole.
Number of moles added = n2 - n1
Number of moles added = 14.12 - 6.51
Number of moles added = 7.61moles
Therefore, 7.61 moles of the gas was added into the system
A houseplant is placed on a window sill that gets direct, bright sunlight
every afternoon. The plant starts to grow toward the window What kind
of response is described by situation?
A
A negative response to a stimulus
6
A learned behavior
c
Gravitropism
D
Phototropism
Answer:
D. Phototropism
Explanation:
Plants, like every other living organism, responds to external stimulus. In this question, the stimulus is LIGHT from the sun entering through the window sill. The plant is responding positively to the light stimuli by growing towards the direction where the light is coming from. This exhibit is called PHOTOTROPISM.
Phototropism, comes from two words viz photo- meaning light and tropism- meaning movement. Hence, phototropism is the growth of an organism (plant in this case) in response to a light stimulus. The case described in this question is POSITIVE PHOTOTROPISM because the growth occurs towards the light source.
Copper metal of 1.23 g sample is reacted completely with chlorine gas to produce
2.61 g of copper chloride. Determine the empirical formula of the compound?
Answer: The empirical formula of the compound is [tex]CuCl_2[/tex]
Explanation:
Mass of Copper (Cu) = 1.23 g
Mass of Chlorine (Cl) = Mass of copper chloride - mass of copper = (2.61 - 1.23) g = 1.38 g
Step 1 : convert given masses into moles
Moles of Cu =[tex]\frac{\text{ given mass of Cu}}{\text{ molar mass of Cu}}= \frac{1.23g}{63.5g/mole}=0.019moles[/tex]
Moles of Cl =[tex]\frac{\text{ given mass of Cl}}{\text{ molar mass of Cl}}= \frac{1.38g}{35.5g/mole}=0.038moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Cu =[tex]\frac{0.019}{0.019}=1[/tex]
For Cl = [tex]\frac{0.038}{0.019}=2[/tex]
The ratio of Cu : Cl = 1 : 2
Hence the empirical formula is [tex]CuCl_2[/tex]
Isomers of hydrocarbons have the same _______formula but different ____formula.
Answer:
Isomers of hydrocarbons have the molecular formula but structural formula.
Explanation:
Molecules with the same structural formula, but different molecular geometries (spatial arrangement) are called isomers. These differences in the arrangement of the various atoms confer certain differences in chemical properties to the resulting hydrocarbons, even though their chemical composition is the same. There are two types of isomers:
Structural isomers: Here, each atom are connected or bonded in different ways, hence structural isomers may contain different functional groups or pattern of bonding. structural isomers are further divided into: chain, position, and functional group isomers.
Stereoisomers: Here, the connections of the atoms are the same, but the difference is in their orientation in space
How is the salt formed in a neutralization reaction written in a chemical reaction?
Answer:
A neutralization reaction between an acid and a base will produce a salt and water. In a neutralization reaction, the acid will produce H+ ions that react to neutralize the OH- ions produced by the base, forming neutral water. ... A weak acid + a strong base in an acid/base neutralization reaction will form a basic salt
Explanation:
What inference can be drawn from the graph?
A + B C + D
A
The reaction between A and B is reactant favored.
B.
The amount of product is greater than the amount of reactant.
C. The reaction uses all its reactants to form products.
D
The reaction reaches equilibrium at 15 seconds
If you touch a hot stove, the nervous system works closely with which other organ system to help your body react by pulling away quickly
1 Skeletal System
2 Muscular System
3 Digestive System
4 Circulatory System
Answer:
2. Muscular System
Explanation:
The muscular system is associated with body motion. Hence, the right answer is option 2.
What is the symbol for the chlorine ion that forms when chlorine nonmetal reacts with sodium? A. C +1 B. Cl -1 C. Cl+1 D. C -1
Answer:
B. Cl -1
Explanation:
Chlorine has 7 valence electrons and needs one more to complete its octet thus takes one electron from sodium to become negatively charged Cl^-1.
What must be known to determine the nature of the salt formed from a weak acid and weak base?
a. the strength of the salt only
b. the strength of the acid only
c. the strength of the base only
d. the strength of both acid and base
A doctor orders 4.0 mg of morphine. The vial of morphine on hand is 20. mg per 2.0 mL . How many milliliters of morphine should you administer to the patient?
which compound is saturated hydrocarbon
Answer:
alkanes are saturated
Answer: alkane
Explanation: because carbon is bonded to the maximum number of hydrocarbons e.gCH4
Which one of the following bonds would be best categorized as covalent
(molecular)? 1. H--S 2. S--O 3. N--F
1 only
1 and 2
1 and 3
1, 2 and 3
Answer:
1, 2 and 3
Explanation:
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons , is known as covalent bonding.
A covalent bond involves as stated above, the mutual sharing of one or more electron pairs of between two atoms. These electrons are simultaneously attracted by the two atomic nuclei. A covalent bond forms when the difference between the electronegativities of two atoms is too small for an electron transfer to occur to form ions. Shared electrons located in the space between the two nuclei are called bonding electrons. The bonded pair is the binding factor that holds the two atomic nuclei together in molecular units.
A covalent bond is commonly formed between two nonmetals. As we can see in the question; 1, 2 and 3 represents bonds formed between two nonmetallic elements. Hence they are rightly classified as molecular or covalent bonds.
The ingredients of the soda are best described as : Mixtures, compounds, or elements.
Answer:
Compound
Explanation:
Soda itself is a mixture made out of compounds.
Answer:
Its B - Compounds
Explanation:
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