Which is greater: the number of atoms in one mole of calcium, or the number of molecules in one mole of carbon dioxide (CO2)?

The correct option is (c). The second chemist must have added a catalyst for the reaction, thus providing a different reaction pathway for the reactant particles to react with an activation energy that was lower than that of the uncatalyzed reaction in the first chemist's experiments.

A catalyst acts as an intermediate between two reactants, increasing the reaction rate and allowing the reaction to occur at lower temperatures and pressures. By lowering the activation energy needed for the reaction, the reaction rate is increased.

Thus, the second chemist adding a catalyst explains why the reaction rate was greater than what the first chemist observed even when the concentrations of the reactants and the temperature in the laboratory were the same.

Therefore, the correct answer is (c).

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Answer:

Ytterbium is a chemical element with the symbol Yb and atomic number 70. It is the fourteenth and penultimate element in the lanthanide

25 gigaseconds is equal to 2,500,000,000,000 centiseconds

Answer:Copper is a chemical element with symbol Cu and atomic number 29. Classified as a transition metal, Copper is a solid at room temperature.So copper is a pure substance in any form (only copper atoms). ... A mixture of different kinds of metal atoms is called an "alloy" if they are mixed on an atomic scale.

The pH of the solution after the addition of HCl is 9.24.

The pH of a buffer containing 0.44 M base, B, and 0.38 M conjugate acid, BH, is 8.82. The buffer equation is BH + H2O ⇌ B + H3O+.

To find the pH after the addition of HCl, we need to use the Henderson-Hasselbalch equation.

pH = pKa + log [B]/[BH]

Where pKa is the negative logarithm of the acid dissociation constant (Ka) for the conjugate acid (BH).

Since BH is the conjugate acid of B, the Ka of BH is equal to the Kb of B. Kb is the base dissociation constant.

The Kb of B can be calculated using the following equation.

Kb = Kw/Ka,

where Kw is the ion product constant of water (1.0 x 10^-14).

We can rearrange the equation as follows.

Ka = Kw/Kb

Ka = 1.0 x 10^-14/Kb

Ka = 1.0 x 10^-14/1.4 x 10^-5

Ka = 7.14 x 10^-10

Now we can calculate the pKa.

pKa = -log Ka = -log (7.14 x 10^-10) = 9.15

Now we can use the Henderson-Hasselbalch equation to find the pH.

pH = pKa + log [B]/[BH]

pH = 9.15 + log (0.44/0.38)

pH = 8.82

When HCl is added to the buffer, it reacts with the base to form its conjugate acid.

HCl + B ⇌ BH+ + Cl-.

We can calculate the moles of base initially present in the solution.

Moles of base = Molarity x Volume = 0.44 x 0.51 = 0.2244 mol

We can calculate the moles of HCl added to the solution.

Moles of HCl = Molarity x Volume = 0.035 x 0.51 = 0.0179 mol

Since HCl is a strong acid, it completely dissociates in solution to form H+ and Cl-. The H+ ions react with the conjugate base to form its conjugate acid.

H+ + B ⇌ BH+.

We can use the following equation to calculate the concentration of the conjugate acid after the addition of HCl.

[BH] = ([OH-] + Kb - sqrt([OH-]^2 + 2Kb[OH-]))/Kb

First, we need to find the concentration of hydroxide ions (OH-) in solution.

We can use the following equation to find the concentration of hydrogen ions (H+).

[H+] = Moles of HCl added/Volume of solution

[H+] = 0.0179/0.51 = 0.035

The concentration of hydroxide ions can be calculated using the following equation.

Kw = [H+][OH-]

1.0 x 10^-14 = 0.035[OH-][OH-] = 1.0 x 10^-14/0.035[OH-] = 2.86 x 10^-13

Now we can calculate the concentration of the conjugate acid.

[BH] = ([OH-] + Kb - sqrt([OH-]^2 + 2Kb[OH-]))/Kb

[BH] = (2.86 x 10^-13 + 1.4 x 10^-5 - sqrt((2.86 x 10^-13)^2 + 2 x 1.4 x 10^-5 x 2.86 x 10^-13))/1.4 x 10^-5

[BH] = 0.378 M

Finally, we can use the Henderson-Hasselbalch equation to find the pH of the solution after the addition of HCl.

pH = pKa + log [B]/[BH]

pH = 9.15 + log (0.44/0.378)

pH = 9.24

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Answer:

The new moles of the gas in the flask is 2.13 moles.

Explanation:

Given;

number of moles of gas, n = 1.9 mol

temperature of the gas, T = 21 °C  = 21 + 273 = 294 K

pressure of gas, P = 697 mmHg

volume of gas, V = ?

Apply ideal gas law;

PV = nRT

Where;

R is gas constant, = 62.363 mmHg.L / mol. K

V = nRT / P

V = (1.9 x 62.363 x 294) / 697

V = 49.98 L

New pressure of the gas, P = 795 mmHg

New temperature of the gas, T = 26 °C = 273 + 26 = 299 K

New moles of the gas, n = ?

Volume of the gas is constant because volume of the flask is the same when more gas was added.

n = PV / RT

n = (795 x 49.98) / (62.363 x 299)

n = 2.13 moles

Therefore, the new moles of the gas in the flask is 2.13 moles.

Answer: Water

Explanation:

The direction in which the proteins migrate during electrophoretic separation of serum proteins at pH 8.6 is determined by their net charge.

The migration of proteins during electrophoresis is determined by their net charge, which is influenced by the pH of the surrounding medium. At pH 8.6, which is relatively alkaline, the proteins in serum typically carry a net negative charge.

In an electric field, proteins with a net negative charge will migrate towards the positively charged electrode (anode) because oppositely charged particles are attracted to each other.

Therefore, in electrophoretic separation of serum proteins at pH 8.6, the proteins will migrate towards the anode, moving in the direction opposite to the migration of the negatively charged ions present in the buffer solution.

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Answer:

d

Explanation:

Answer:

hi!!

Explanation:

first we search for the volumic mass :

volumic mass = mass/volum=465/60.0 = 7.75 gper cubic centimeters

density = volumic mass of the tin box / volumic mass of water = 7.75/ 1 (g per cubic centimeters)= 7.75

The rate of the reaction can be obtained as  0.004 Ms-1.

We know that the rate of reaction is the rate of the change of the concentration with time of the system.

The rate of a chemical reaction is the speed at which the reactants are converted into products. It is usually expressed as the change in concentration of a reactant or product per unit time.

Rate of reaction = Change in concentration/ Time

= 0.5 - 0.35/35

= 0.004 Ms-1

Thus the reaction is is calculated as 0.004 Ms-1.

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#SPJ1If magnesium is added to hydrochloric acid, the reaction takes 35 seconds to go to completion. It was found to change the hydrochloric acid from 0.5 M to 0.35 M. What is the rate of reaction?

The diffusion of carbon in iron occurs through an interstitial mechanism which happens in bcc iron from one tetrahedral site to another.

The carbon atoms diffuse through the iron lattice and are located in the interstitial sites within the lattice.

This interstitial mechanism is observed to happen in the Body centered cubic (BCC) structure of iron, and the carbon atoms fill the tetrahedral voids of the bcc iron lattice.

Interstitial diffusion of carbon in BCC iron involves the movement of a carbon atom from one tetrahedral site to another.  

The interstitial diffusion of carbon in iron is responsible for the hardening of steel via heat treatment, which makes the steel stronger and more durable.

This property is used in the manufacturing of steel tools and machinery components that are expected to endure high stress.

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Answer:

Water is a remarkable substance, and its unique properties are largely due to the presence of polar covalent bonds and hydrogen bonds in its structure. These characteristics play a crucial role in the physical and chemical properties of water, making it essential for life as we know it.

Explanation:

The polar covalent bonds in water arise from the unequal sharing of electrons between oxygen and hydrogen atoms. This results in the oxygen atom having a partial negative charge (δ-) and the hydrogen atoms having partial positive charges (δ+). These charges create polarity within the water molecule, leading to the formation of hydrogen bonds.

Hydrogen bonds occur when the partially positive hydrogen atom of one water molecule is attracted to the partially negative oxygen atom of another water molecule. These hydrogen bonds are relatively weak individually, but when present in large numbers, they contribute to the cohesion, surface tension, and high boiling point of water.

The importance of these bonds is manifold. The cohesion between water molecules due to hydrogen bonding enables water to form droplets, have a high surface tension, and flow freely, facilitating transport within organisms and in the environment. Additionally, hydrogen bonding leads to the high specific heat capacity and heat of vaporization of water, making it an effective regulator of temperature in living organisms and ensuring stable environmental conditions.

Furthermore, hydrogen bonds play a crucial role in the unique properties of water as a solvent. The polar nature of water allows it to dissolve a wide range of substances, including ionic compounds and polar molecules, facilitating various biological processes such as nutrient transport and chemical reactions in cells.

If all four substances were exposed to sunlight for the same amount of time, brick is the substance that heats up the slowest. Option D is correct.

The certain heat of brick is 0.9, which specifies that it needs less heat energy to increase its temperature compared to the other substances listed

Particularly, brick has a lower heat size, meaning it can engross less heat energy per unit mass. Accordingly, when exposed to sunlight, the brick will heat up in proportion slowly compared to the other substances.

So, the substance that would heat up the slowest when exposed to sunlight for the same duration is brick.

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As a result, there are two moles of a NaNO3 for every mole of Cu(NO3)2.

The representation of molecules. When copper(II) nitrate and sodium hydroxide solutions are combined, a combination of sodium nitrate solution and the copper(II) hydroxide precipitate is created.

The balanced chemical equation for the reaction between Cu(NO3)2 and NaNO3 is:

Cu(NO3)2 + 2 NaNO3 → Cu(NO3)2 + 2 NaNO3

Since the coefficients of NaNO3 and Cu(NO3)2 are equal

The number of moles of NaNO3 is equal to the number of moles of Cu(NO3)2 in this reaction.

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Answer:

Visible light waves let you see the world around you. The different frequencies of visible light are experienced by people as the colors of the rainbow.

Explanation:

Answer

b. It produces carbon dioxide when burned in pure oxygen.

Explanation

The reaction between diamond and oxygen, producing carbon dioxide is not a physical property of diamond, it is a chemical property because breaking and synthesis of chemical bonds occur.

The number of moles of oxygen and nitrogen in the gas sample. The volume of the gas sample at STP (standard temperature and pressure), containing 1.42 g oxygen and 1.84 g nitrogen is 44.8 L.


To solve this problem, we need to use the ideal gas law, which is PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.
At STP (standard temperature and pressure), the pressure is 1 atm and the temperature is 273 K. Therefore, we can simplify the ideal gas law to: V = nRT/P.

To find the volume, we first need to determine the moles of each gas.
Calculate the moles of oxygen and nitrogen:
Oxygen (O2):
Molar mass = 16 g/mol (for O) * 2 = 32 g/mol (for O2)
Moles = mass / molar mass = 1.42 g / 32 g/mol = 0.0444 mol
Nitrogen (N2):
Molar mass = 14 g/mol (for N) * 2 = 28 g/mol (for N2)
Moles = mass / molar mass = 1.84 g / 28 g/mol = 0.0657 mol.

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In general, the average atomic mass of an element is calculated based on the percent composition of its isotopes and their respective masses. Isotopes are atoms of the same element that have different numbers of neutrons and, therefore, different masses.

The percent composition represents the relative abundance of each isotope in a given sample of an element. It is usually expressed as a percentage and reflects the proportion of each isotope present.

The relationship between the average atomic mass, percent composition, and each isotope's mass can be described as follows:

The average atomic mass is a weighted average of the masses of all the isotopes of an element, with the weights determined by their percent composition. Isotopes with higher percent composition contribute more to the average atomic mass.

The percent composition of each isotope is determined by the natural abundance or the frequency of occurrence of that isotope in nature. Isotopes with higher natural abundance will have a greater influence on the percent composition.

Each isotope's mass is a constant property and represents the actual mass of the individual isotope. The different masses of isotopes contribute to the variation in the average atomic mass.

Based on this understanding, a hypothesis could be that the average atomic mass of an element will be closer to the mass of the most abundant isotope if the percent composition of that isotope is higher. Conversely, if the percent composition of a less abundant isotope is higher, it would have a greater influence on the average atomic mass, causing it to deviate more from the mass of the most abundant isotope.

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To determine the reaction order in [Mn²+], we need to compare the initial rates of the reaction in different experiments where the [Mn²+] is varied while keeping the [H₂O₂] constant.

From the given data, we can see that in Experiment 1, the [Mn²+] is 0.740 M and the initial rate is 0.034 M/s. In Experiment 2, the [Mn²+] is 0.219 M and the initial rate is 0.00301 M/s. In Experiment 3, the [Mn²+] is 0.740 M and the initial rate is 0.0486 M/s.

To determine the reaction order in [Mn²+], we need to compare the initial rates of the reaction in Experiments 1 and 2, where the [Mn²+] is varied while keeping the [H₂O₂] constant. Therefore, we can conclude that the reaction order in [Mn²+] is first order, as the initial rate of the reaction decreases by a factor of ~11 when the [Mn²+] is reduced from 0.740 M to 0.219 M.

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a) The percentage abundance determines the relative atomic mass.

b) The relative atomic mass for the element X is122.5 amu

c) The Rutherford's model explained showed the movement of the electrons.

The isotopes are the kinds of atoms of an element that we can see. We know that all the element that we have in the periodic table are composed of the isotopes and the isotopes of the elements are important in the determination of the relative atomic mass of the element that we may be considering here called X

We can now be able to see from the forgoing that we have here that;

Relative atomic mass = Weighted average of all the isotopes

As such we have;

(121 * 0.432) + (123 * 0.531) + (129 * 0.0370)

52.27 + 65.31 + 4.773

=122.35 amu

The Rutherford model of the atom can also be called the planetary model of the atom and this is the model that can be able to explain to us the way that the electrons move round the nucleus.

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Answer:

I can i have done this before

Explanation:

hope this helps

may i get braineist

btw im in 5th grade too  i have the same worksheets i can help if your behind. i got an 100% on this

Answer: Unknown

Explanation:

In order to solve the question you would require the approximate amount of gravity upon the diver, meaning his acceleration due to gravity.

Answer:

I believe it would be a solution I could be wrong tho

Explanation:

Answer:

a solution

Homogeneous mixtures (solutions)

Explanation:

Lemonade is a special type of mixture called a solution.

...................................................................................................................................................

What type of mixture is made by thoroughly mixing powdered lemonade with water?

Homogeneous mixtures (solutions)

Mixtures with substances dissolved evenly into one another, like pink lemonade powder dissolved in water, are called homogeneous mixtures, or solutions.

The fugacity in atm for pure ethane at 310 K and 20.4 atm is given by the equation: f = 20.4 exp (-Δg1/RT). The change in chemical potential between this state and a second state of ethane where the temperature is constant but the pressure is 24 atm is -0.0911RT.

Fugacity is a measure of the escaping tendency of a component in a mixture, which is defined as the pressure that the component would have if it obeyed ideal gas laws. It is used as a correction factor in the calculation of equilibrium constants and thermodynamic properties such as chemical potential. Here we need to determine the fugacity in atm for pure ethane at 310 K and 20.4 atm and the change in the chemical potential between this state and a second state of ethane where the temperature is constant but the pressure is 24 atm. So, using the formula of fugacity: f = P.exp(Δu/RT) Where P is the pressure of the system, R is the gas constant, T is the temperature of the system, Δu is the change in chemical potential of the system.  Δu = RT ln (f / P)The chemical potential at the initial state can be calculated using the ideal gas equation as: PV = nRT    

=>  P

= nRT/V

=> 20.4 atm

= nRT/V

=> n/V

= 20.4/RT The chemical potential of the system at the initial state is:

Δu1 = RT ln (f/P)

= RT ln (f/20.4) Also, we know that for a pure substance,

Δu = Δg. So,

Δg1 = Δu1 The change in pressure is 24 atm – 20.4 atm

= 3.6 atm At the second state, the pressure is 24 atm.

Using the ideal gas equation, n/V = 24/RT The chemical potential of the system at the second state is: Δu2 = RT ln (f/24) = RT ln (f/24) The change in chemical potential is Δu2 – Δu1 The change in chemical potential is

Δu2 – Δu1 = RT ln (f/24) – RT ln (f/20.4)

= RT ln [(f/24)/(f/20.4)]

= RT ln (20.4/24)

= - 0.0911 RT Therefore, the fugacity in atm for pure ethane at 310 K and 20.4 atm is:

f = P.exp(Δu/RT)

=> f

= 20.4 exp (-Δu1/RT)

=> f

= 20.4 exp (-Δg1/RT) And, the change in the chemical potential between this state and a second state of ethane where the temperature is constant but pressure is 24 atm is -0.0911RT. Therefore, the fugacity in atm for pure ethane at 310 K and 20.4 atm is given by the equation: f = 20.4 exp (-Δg1/RT). The change in chemical potential between this state and a second state of ethane where the temperature is constant but the pressure is 24 atm is -0.0911RT.

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Extensive properties depend on the amount of matter in a sample, While Intensive properties do not depend on the amount of matter in a substance.

At the end of mitosis, the cells are genetically identical to each other. Therefore, option B is correct.

Mitosis is the process by which a cell replicates and then segregates its chromosomes, producing two identical nuclei in preparation for cell division.

Meiosis produces four haploid (n) gametes that are genetically distinct from each other and the original parent (germ) cell, whereas mitosis produces two diploid (2n) somatic cells.

Mitosis results in the formation of two identical daughter cells, each with the same number of chromosomes as the parent cell.

Thus, option B is correct.

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Answer:

genetically identical to each other

Explanation:

Answer:

invalid

Explanation:

Just imagine doing this experiment MULTIPLE TIMES and one of the trials you get 72 Kcal while in another u get 12kcal. It doesn't make sense. Somewhere in the experiment she went wrong. So its invalid