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2 years ago

What is the molar concentration of [H3O+] in a cola that has a pH of 3.120?

Chemistry

1 answer:

ELEN [110]2 years ago

8 0

Answer:

[H₃O⁺] = 7.586×10⁻⁴ M

Explanation:

The pH of a solution is a measure of the molar concentration of H₃O⁺ ions in the solution.

The mathematical expresssion that states the relation between the molar concentration of H₃O⁺ ions and the pH of the solution is:

pH = - log [H₃O⁺].

This is pH is numerically equal to the negative decimal logarithm of the molar concentration of H₃O⁺.

The square brackets are used to indicate molar concentration.

Thus:

pH = - log [H₃O⁺] ← equation

3.120 = -log [H₃O⁺] ← substituting values

- 3.120 = log [H₃O⁺] ← product property of the multiplication

$10^{- 3.120}=[H_3O^+]$ ← antilogarithm property

[H₃O⁺] = 7.586×10⁻⁴ M ← result

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A 10.0 g sample of an unknown liquid is vaporized at 120.0°C and 5.0 atm. The volume of the vapour is found to be 568.0 mL. The

Minchanka [31]

Answer:

molecular formula of liquid = C₈H₁₈

Explanation:

First we determine the empirical formula of the liquid:

Number of moles of each element present in the liquid = % mass / molar mass

For Carbon, (molar mass = 12.01 g/mol) : 84.2/12.01 =7.011 moles

For Hydrogen (molar mass = 1.01 g/mol) : 15.8/1.01 = 15.643

Simplest mole ratio of the elements, C : H is given by:

C = 7.011/7.011 = 1.0

H = 15.643/7.011 = 2.23

Multiplying through with 5, C:H = 5:11

Therefore, empirical formula is C₅H₁₁

The molecular mass of the liquid is next determined:

Using PV = nRT to find the number of moles of the liquid present

P = 5.0 atm; V = 568.0 mL = 0.568 L; R = 0.082 L*atmmol⁻¹ K⁻¹; T = 273 + 120 = 393 K

n = PV/RT = (5*0.568)/0.082*393

n = 0.088 moles

Molar mass of liquid = mass/no of moles = 10.0 g/ 0.088 moles = 113.63 gmol⁻¹

Molecular formula = n(empirical formula)

Molar mass of empirical formula, C₅H₁₁ = 71 gmol⁻¹

n = molecular mass/empirical mass = 113.63/71 = 1.6

Therefore, molecular formula = 1.6*(C₅H₁₁) = C₈H₁₈

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2 years ago

Which elements consists of a metal a matalloid and a noble gas

maw [93]

The answer is sodium silicon and argon

4 0

3 years ago

3. How many atoms in 3.91 moles of sodium?

Gala2k [10]

Answer:

Explanation:

The formula for sodium is Na. It does not form a molecule in some way.

1 mol Na = 6.02*10^23 atoms

3.91 mol = x Cross multiply

x = 3.91 * 6.02 * 10^23

x = 23.65 * 10^23

x = 2.365 * 10^24

Scientific notation is always expressed as a number 1 ≤ x < 10

3 0

3 years ago

Consider this equilibrium reaction between carbon monoxide and hydrogen gas, occurring in a sealed flexible container. CO(g) + 3

wariber [46]

Answer:

More H2(g) is added to the container : Towards products.

CO is removed from the container : Towards reactants.

More CH4(g) is added to the container : Towards reactants

H2O(g) is removed from the container : Towards products.

The contents of the container are heated up. : Towards the reactants.

The contents of the container are cooled down : Towards the products.

The pressure inside the container is increased. :Towards the products

The container is stretched to increase the volume: Towards the reactants.

Explanation: :

CO(g) + 3 H2g) → CH4(g) + H2O(g)+ heat

There is released heat, so this reaction is exothermic

If the H2 concentration is increased, the system will try to change the concentration change by shifting the balance to the right, and thus the concentration of products will increase. Towards products.

If the CO is removed, the system will try to change this situation by shifting the balance to the left, and thus the concentration of reactants will increase, the concentration of products will decrease. Towards reactants.

If the CH4 concentration is increased, the system will try to change the concentration change by shifting the balance to the left, and thus the concentration of reactants will increase. Towards reactants

If the H2O is removed, the system will try to change this situation by shifting the balance to the right, and thus the concentration of products will increase, the concentration of products will decrease. Towards products.

If the temperature is increased, the system will reduce the amount of heat released. So the balance will shift to the left. Towards the reactants.

This because the extra heat / energy must be used.

If the temperature is decreased, the system will produce more heat So the balance will shift to the right. Towards the products.

This because more heat /energy needs to be produced to make up for the loss of heat (energy).

If the pressure is increased, the system will shift to the side with fewer moles of gas. In this case, there are 4 moles on the left and 2 moles on the right. So the balance will shift to the right. Towards the products. An increase of pressure has the same effect on the equilibrium as a decrease of the volume.

If the volume is increased, this means the pressure is decreased, the system will shift to the side with most moles of gas. In this case, there are 4 moles on the left and 2 moles on the right. So the balance will shift to the left. Towards the reactants. An increase of volume has the same effect on the equilibrium as a decrease of the pressure.

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3 years ago

Physical and chemical properties of a piece of cooked chicken and a glass of kool-aid

Lunna [17]

A cooked chicken would be somewhat burnt or cooked. A glass of kool aid would be mixed, or aka homogenous mixture. The glass would maintain a color, because its not water.

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3 years ago