Answer:
The molar mass of Na (sodium) is 23.0 g/moles
Explanation:
Answer:
the molar mass of Na (sodium) is 23.0 g/mol.
Explanation:
Substance B is hard, does not conduct electricity, and melts at 1200 °C. Substance B is likely a(n):
(a) ionic solid
(b) metallic solid
(c) molecular solid
(d) covalent network solid
Enough of a monoprotic acid is dissolved in water to produce a 1.64 M solution. The pH of the resulting solution is 2.82 . Calculate the Ka for the acid.
Answer:
Ka = 1.39x10⁻⁶
Explanation:
A monoprotic acid, HX, will be in equilibrium in an aqueous medium such as:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
Where Ka is:
Ka = [H⁺] [X⁻] / [HX]
Where [] is the molar concentration in equilibrium of each specie.
The equilibrium is reached when some HX reacts producing H+ and X-, that is:
[HX] = 1.64M - X
[H⁺] = X
[X⁻] = X
As pH is 2.82 = -log [H⁺]:
[H⁺] = 1.51x10⁻³M:
[HX] = 1.64M - 1.51x10⁻³M = 1.638M
[H⁺] = 1.51x10⁻³M
[X⁻] = 1.51x10⁻³M
And Ka is:
Ka = [1.51x10⁻³M] [1.51x10⁻³M] / [1.638M]
Ka = 1.39x10⁻⁶The chemical bonding of two hydrogen atoms and one oxygen atom forms water. Water is
an atom
an element
a compound
a neutron
Answer:
Atom
Explanation:
Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom Atom AtomAtom Atom Atom
9 What 11 letter word describes the chemical balance within an organism?
___________________________________
10 What 7 letter word describes the waterproof outer layer for soft-bodies creatures?
___________________________________
11 What word starting with the letter "C" is the liquid material found within cells?
___________________________________
12 What word starting with the letter "C" is a process of organizing things into groups scientifically?
___________________________________
Answer:
9.) Homeostasis
10.) Epidermis
11.) Cytoplasim
12.) Classification
Question: Can a penny dropped from a building kill a pedestrian below?
Hypothesis:
Controls:
Independent variable:
Dependent variable:
Conclusion:
Answer:
Hypothesis: IF a penny is dropped from a building, THEN it would kill a pedestrian below
Controls: Same building, Same distance
Independent variable: Penny
Dependent variable: Pedestrian's death
Conclusion: The hypothesis is rejected
Explanation:
- The hypothesis is a testable explanation to an observed problem or asked question. Based on the cientific question in this question, a possible hypothesis will be: IF a penny is dropped from a building, THEN it would kill a pedestrian below
- Independent variable is the variable that is changed or manipulated in an experiment. In this case, the PENNY is the independent variable
- Dependent variable is the variable that responds to the change made to the independent variable. It is the measured variable. In this case, the dependent variable is the DEATH OF PEDESTRIANS.
- Controls are those variables that is kept constant or unchanged throughout the experiment. The controls in this experiment are: Same building, Same distance of throw etc.
- The conclusion is whether the hypothesis is accepted or not depending on the result of the experiment conducted. In this case, the hypothesis will be rejected if the penny doesn't kill a pedestrian
if you wanted to measure in irregular object's volume, which device would you use?
Answer:
a beaker
Explanation:
Organisms in overpopulated area do not survive well due to which of the following
Answer:
Reductions in available food and shelter
Explanation:
To solve this we must be knowing each and every concept related to population. Therefore, organisms in over-populated areas do not survive well due to reduction in available food and shelter.
What is population?The group of people from whom a quantitative sample is gathered for a research is referred to as a population. Therefore, a population is any collection of people who have anything in common.
A sample is a representative group of a population chosen at random. This is a smaller group that was selected from the population and possesses all of the population's traits. The observations and inferences drawn from the sample data then applied to the entire population.
Therefore, organisms in over-populated areas do not survive well due to reduction in available food and shelter.
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What calculated value is used to evaluate accuracy for a set of data? Group of answer choices (multiple choice) yield percent error range
Answer:
Percent error
Explanation:
Percent error is defined as the percentage of the difference between the measured( accurate value) and the known value of a substance.
It is usually calculated by:
Measured value — Known value/ known value * 100%
Percent error is the calculated value that is used to evaluate accuracy for a set of data
Gases A and B are confined to a cylinder and piston and react to form product C. As the reaction occurs, the system loses 1189 J of heat to surroundings. The piston moves downward as the gases react to form a solid. As the volume of the gas decreases under the constant pressure of the atmosphere, the surroundings do 311 J of work on the system. What is the change in the internal energy of the system
Answer:
The change in the internal energy of the system -878 J
Explanation:
Given;
energy lost by the system due to heat, Q = -1189 J (negative because energy was lost by the system)
Work done on the system, W = -311 J (negative because work was done on the system)
change in internal energy of the system, Δ U = ?
First law of thermodynamics states that the change in internal energy of a system (ΔU) equals the net heat transfer into the system (Q) minus the net work done by the system (W).
ΔU = Q - W
ΔU = -1189 - (-311)
ΔU = -1189 + 311
ΔU = -878 J
Therefore, the change in the internal energy of the system -878 J
Which property of a substance can be determined using a pH indicator?
A. acldity
B. bolling polint
C. density
D. electrical conductivity
E. thermal conductivity
Answer:
the correct answer would be A. acidity
Answer:
The answer is A.) Acidity
How many moles of H2 are needed to produce 24 moles of NH3?
Answer:
36 mol of H2
Explanation:
The balanced equation of the reaction is given as;
3H2 + N2 --> 2NH3
From the reaction;
It takes 3 mol of H2 reacting with 1 mol of N2 to form 2 mol of NH3
3 mol of H2 = 2 mol of NH3
x mol of H2 = 24 mol of NH3
x = (24 * 3) / 2 = 36 mol of H2
which two options are examples of chemical changes?
A. A shinny metal bar glows red and expands when heated.
B. white piece of paper turns black and gives off a smell when burned
C. When two clear colorless liquids are mixed together, a white solid forms
D. A white powder mixed with a clear, colorless liquid makes a solution that is also clear, colorless liquid
Answer:
B
Explanation:
It's the only thing that actually changes into something different and when u burn it it makes chemicals
Which of the following BEST describes one of the main functions of proteins?
4. Horizontal rows of the Periodic Table are called:
a, Clusters
Groups
b. Families
d) Periods
please answer these questions properly. I will mark brainiest for the proper answer and pleaaaaaaaaaaaase answer if you know the answer only. if u don't know the answer, leave it please. instead of writing the answer as "sorry I did not understand :)
Answer:
the first three are physicsa, and last 1 is physical the other two are chemical
Explanation:
In Fig 1-2, how should the length indicated by the arrow along the ruler be recorded?
Answer:
C. 0.35cm
Explanation:
The length indicated by the arrow along the ruler should recorded be recorded as "0.35cm".
This is correct because when counting the measurement on the ruler, the first line on the ruler is 0.1cm, the second line is 0.2cm, and so on. The spaces between each line is 0.05cm. So, the arrow is pointing on the space between 0.3cm and 0.4cm.
Therefore, 0.3cm + 0.05cm = 0.35cm.(answer).
How many carbon atoms are in vitamin c?
Answer:
molecules can be much bigger. one molecule of vitamin c is made up of 20 atoms (6 carbons, 8 hydrogens, and 6 oxygens
when 3000 grams of water is cooled from 80.0 c to 10.0 c, how much energy is released
Answer:
877800 Joules of energy is released
Explanation:
mass m = 3000 g
initial temperature = 80 c
Final temperature = 10 c
Change in temperature ΔT = 80 - 10 = 70 c
Heat H = ?
The relationship between these parameters is given by;
H = mcΔT
Where c = specific heat capacity = 4.18 J/gc
H = 3000 * 4.18 * 70 = 877800 Joules
An object is moving at a speed of 6 inches every 4.5 days. Express this speed in yards per year. Round your answer to the nearest tenth.
The definition of average speed and unit reductions allows to find the result for the speed of the object is:
The velocity is: v = 13.5 [tex]\frac{yard}{year}[/tex]
Kinematics studies the movement of bodies, looking for relationships between the position, velocity and acceleration of bodies.
Average velocity is defined as the change in position between the interval time
v = [tex]\frac{\Delta x}{\Delta t}[/tex]
Where v is the velocity, Δx and Δt the change in position and time, respectively.
The system of units is a system that allows the exchange of data and values with precision and without errors, the most used system in the world is the international system of measurements (SI), another system also used is the English system, where the basic units are the foot and the second.
They indicate the displacement in the form of a 6-inch in a time of 4.5 days. Let's look for speed.
v = [tex]\frac{6 \ inch}{4.5 \ day }[/tex]
v = 1.3333 inch/days
They ask that I know this speed in yards per year, let's reduce the units.
1 yard = 36 in
1 year = 365 days
Let's reduce.
v = [tex]1.33333 (\frac{inch}{day}) \ (\frac{1 yard}{36 inch}) \ ( \frac{365 day }{1 year} )[/tex]
v = 13.52 yard / year
The result is requested with a nearest tenth.
v = 13.5 yard / year
In conclusion using the definition of average speed and unit reductions we can find the result for the speed of the object is:
The veloicity is: v = 13.5 [tex]\frac{yard}{year}[/tex]
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Which set of procedures would be best to follow when separating a mixture of sand, salt, and water?
Answer:
Pour the mixture through a filter to separate the sand, then evaporate the liquid to separate the salt.
Explanation:
There are various methods used to separate single substances from a mixture. The method adopted depends upon the type of mixture and the ingredients used in it. According to the given question, the mixture comprises of sand, salt and water. Here, the first process will be the process of filtration. Through filtration, the salt-water solution and sand can be separated. Salt-water solution can be separated by the process of evaporation in which sat and water will be separated individually.
What color is the acetic acid plus methyl orange solution and what does this tell you about where the equilibrium is
Answer:
Red
Explanation:
Acetic acid is an acidic medium. Recall that indicators are organic substances whose color changes in response to change in the pH of the solution. often times, the protonated and deprotonated forms of an indicator have different colors.
However, an equilibrium is set up when an indicator is in acid/ basic medium. Methyl orange is red in acid medium and yellow in basic medium.
Hence while in acetic acid, the equilibrium lies towards the protonated form of acetic acid, hence the solution appears red.
Which of the following best describes the structure of a nucleic acid?
a. Carbon ring(s)
b. Globular or fibrous
c. Single or double helix
d. Hydrocarbon(s)
Consider a 180. g sample of water. The specific heat of water is 1.00 cal(g · °C) or 4.18 J/(g: °0).
(a) How much energy, in calories, is released as the water is cooled from 55.0°C to 12.0°C? (Enter your
answer in scientific notation.)
Answer:
Explanation:
How to add a great answer
ADD YOUR ANSWER
Question
Consider a 180. g sample of water. The specific heat of water is 1.00 cal(g · °C) or 4.18 J/(g: °0).
(a) How much energy, in calories, is released as the water is cooled from 55.0°C to 12.0°C? (Enter your
answer in scientific notation.)
* Sodium has an atomic number of 11 and a mass number of 23.
Which of the following are the correct number of protons,
neutrons, and electrons, respectively, in a neutral sodium
atom?
Answer:
11 Protons, 12 Neutrons, 11 Electrons.
Explanation:
The number of protons is the same as the atomic number for any element. Since protons and neutrons both weigh about 1amu, if we subtract 11 from 23, we can find the mass of the neutrons which is 12. Since we know that the atom is a neutral atom, there is no charge which tells us that the number of protons and electrons are the same.
Which of the following has the correct arrangement of atoms in order of increasing atomic radius?
A). Mg, Na, P, Si, Ar
B). Ar, Mg, P, Na, Si
C.) Na, P, Si Mg, Ar
D.) Ar, P, Si, Mg, Na
Answer:
The correct answer is - option D. Ar, P, Si, Mg, Na
Explanation:
The atomic radius of an atom can be defined as half of the distance of the nucleus of two atoms in a diatomic molecule which is represented by r. This can be measure by measuring the distance of the nuclei in a diatomic molecule and divide it by 2.
Argon (Ar) - 0.71 Å
Phosphorus (P) - 0.98 Å
Silicon (Si) - 1.11 Å
Magnesium (Mg) - 1.45 Å
Sodium (Na) - 1.9 Å
Atmic radii is decreses as moving from left to right across a period in periodic table.
Three colorless solutions in test tubes, with no labels, are in a test tube rack on the laboratory bench. Lying beside the tests tubes are three labels : 0.10 M Na2CO3, 0.10 M HCL, and 0.10 M KOH. You are to place the labels on the test tubes using only the three solutions present. Here are your tests:
A few drops of the solutions from test tube 1 added to a similar volume of the solution in test tube 2 produces no visible reaction but the solution becomes warm.
A few drops of the solution from test tube 1 added to a similar volume of the solution in test tube 3 produces carbon dioxide gas.
Identify the labels for test tubes 1, 2, and 3
Answer:
Test tube 1 0.10 M HCL
Test tube 2 0.10 M KOH
Test tube 3 0.10 M Na2CO3
Explanation:
From the question we are told that
A few drops of the solutions from test tube 1 added to a similar volume of the solution in test tube 2 produces no visible reaction but the solution becomes warm
Generally this warmth is as a result of a reaction between an acid and a base and the acid is 0.10 M HCL and the base is 0.10 M KOH , the heat generated is know as the heat of neutralization,
The reaction is
[tex]HCl_{(aq)} + KOH_{(aq)} \rightarrow KCl_{(aq)} + H_2O_{(l)} + \Delta H[/tex]
We are also told from the reaction that
A few drops of the solution from test tube 1 added to a similar volume of the solution in test tube 3 produces carbon dioxide gas.
Generally carbon dioxide gas is produced is as a result of a reaction between the acid HCl and Na2CO3.
The reaction is
[tex]2HCl -{(aq)} + Na_2 CO_3_{(aq)} \rightarrow 2 NaCl _{(aq)} + CO_2_{(g)} + H_2O_{(l)}[/tex]
Hence from this explanation above we see that the solution in test tube 1 is 0.10 M HCL while solution in test tube 2 is 0.10 M KOH and then solution in test tube three is 0.10 M Na2CO3
N2H4+H2O2 ——> N2+H2O coefficient
Answer:
N2H4 + 2H2O2 ---->N2 + 4H2O
Explanation:
N=2 N=2
H=6 ->8 H=2 ->8
O=2 -> 4 O=1 -> 4
Add coefficients to hydrogen peroxide on the left and water on the right, so that there is an equal number of hydrogens and oxygens.
1.
Light near the middle of the ultraviolet region of the electromagnetic spectrum
has a frequency of 2.73 X 1016 s-1
a.
What is the wavelength of this radiation in meters (m)?
b.
What is the energy associated with this radiation in kcal?
Explanation:
Given that,
The frequency of electromagnetic spectrum is [tex]2.73\times 10^{16}\ Hz[/tex]
(A) Let the wavelength of this radiation is [tex]\lambda[/tex]. We know that,
[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{2.73\times 10^{16}}\\\\\lambda=1.09\times 10^{-8}\ m[/tex]
So, the wavelength of this radiation is [tex]1.09\times 10^{-8}\ m[/tex].
(B) Let E is the energy associated with this radiation. Energy of an electromagnetic radiation is given by :
[tex]E=hf[/tex]
h is Planck's constant
[tex]E=6.63\times 10^{-34}\times 2.73\times 10^{16}\\\\E=1.8\times 10^{-17}\ J[/tex]
1 kcal = 4184 J
It means,
[tex]1.8\times 10^{-17}\ J=\dfrac{1}{4184}\times 1.8\times 10^{-17}\\\\=4.3\times 10^{-21}\ \text{kcal}[/tex]
Hence, this is the required solution.
Consider the rechargeable battery: Zn(s)0ZnCl (aq)7Cl2(aq)0Cl (l)0C(s) (a) Write reduction half-reactions for each electrode. From which electrode will electrons flow from the battery into a circuit if the electrode potentials are not too different from E 8 values
Complete Question
Consider the rechargeable battery: [tex]Zn(s)||ZnCl _{(aq)}||Cl_2_{(aq)}|Cl_2 (l)|C_{(s)}[/tex]
(a) Write reduction half-reactions for each electrode. From which electrode will electrons flow from the battery into a circuit if the electrode potentials are not too different from [tex]E^o[/tex] values
(b)
if the battery delivers a constant current of [tex]1 .00 *10^{3} \ A[/tex] for 1.00 h , how many kg of [tex]Cl_2[/tex] will be consumed
Answer:
a
At the anode
[tex]Zn^{2+} + 2e^{-} \to Zn_{s} \ \ \ E^o = -0.762 V[/tex]
At the cathode
[tex]Cl_2 _{(l)} + 2e^{-} \to 2Cl^{-} _{aq} \ \ \ \ E^o = 1.396 V[/tex]
b
The value is [tex]mCl = 1.32583 \ kg [/tex]
Explanation:
Generally the half-reactions for each electrode is mathematically represented as
At the anode
[tex]Zn^{2+} + 2e^{-} \to Zn_{s} \ \ \ E^o = -0.762 V[/tex]
At the cathode
[tex]Cl_2 _{(l)} + 2e^{-} \to 2Cl^{-} _{aq} \ \ \ \ E^o = 1.396 V[/tex]
Generally from the question we are told that
The current is [tex]I = 1.00 *10^{3} \ A[/tex]
The time is [tex]t = 1.00\ h= 3600[/tex]
Generally the quantity of charge consumed is
[tex]Q = It[/tex]
=> [tex]Q = 1.00 *10^{3} * 3600 [/tex]
=> [tex]Q = 3.6 *10^{6} \ C [/tex]
Generally the number of moles of electron consumed is
[tex]n = \frac{Q}{F}[/tex]
Here F is the faradays constant with value [tex]F = (96500C/mole \ e-)[/tex]
So
[tex]n = \frac{ 3.6 *10^{6} }{96500}[/tex]
=> [tex]n = 37.3 \ moles [/tex]
Generally the number of moles of [tex]Cl_2[/tex] consumed is mathematically represented as
[tex]nCl = \frac{1}{2} * n[/tex]
=> [tex]nCl = \frac{1}{2} * 37.3 [/tex]
=> [tex]nCl = 18.7 \ moles [/tex]
Generally the mass of [tex]Cl_2[/tex] consumed is mathematically represented as
[tex]mCl = nCl * Z[/tex]
Here Z is the molar mass of [tex]Cl_2[/tex] is Z = 70.9 g/mole
So
[tex]mCl = 18.7 * 70.9 [/tex]
=> [tex]mCl = 18.7 * 70.9 [/tex]
=> [tex]mCl = 1325.83 \ g [/tex]
=> [tex]mCl = 1.32583 \ kg [/tex]
Convert
12 x 1025 kg/mL to fg/cm3
Answer:
[tex]1.2x10^{38}\frac{fg}{cm^3}[/tex]
Explanation:
Hello there!
In this case, for such unit conversion we need to realize that 1 kg is equal to 1000 g, 1 g is equal to 1x10⁹ and 1 mL equals 1 cm³, therefore we apply:
[tex]12x10^{25}kg*\frac{1000g}{1kg} *\frac{1x10^9fg}{1g} *\frac{1mL}{1cm^3} \\\\1.2x10^{38}\frac{fg}{cm^3}[/tex]
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