Question 1

Which information is necessary to determine the molarity of a solution if the chemical formula of the solute is known?

Accepted Answer

Molarity is defined as the number of moles of solute per liter of solution. To find the molarity, you need the mass of the solute dissolved to calculate the moles of solute (using the molar mass from the chemical formula) and the final volume of the solution to determine the volume in liters.

Question 2

How many grams of NaOH are needed to make 750 mL of a 2.5% (w/v)solution?

Accepted Answer

We can start by using the formula:

mass (g) = volume (mL) x concentration (w/v)

Converting the given volume to grams:

750 mL x 1 g/mL = 750 g

Substituting the values into the formula:

mass (g) = 750 g x 2.5% = 18.75 g

Rounding off to the nearest gram, we get:

mass (g) = 19 g

Therefore, the correct answer is C) 19 g.

Question 3

What is the molarity of a solution prepared by dissolving 0.750 mol CaCl₂ in enough water to make 0.500 L of solution?

Accepted Answer

The answer of What is the molarity of a solution...

Question 4

All of the statements about molarity are correct except

Accepted Answer

The interpretation of the symbol for molarity is "moles of solute per liter of solution", not "moles of solute per mole of solvent".

Question 5

Which solution is the least concentrated? Each choice refers to the same solute and solvent.

Accepted Answer

The concentration of a solution is determined by the ratio of solute to solvent. In choice D, the ratio of solute (30 g) to solvent (150 mL) is the lowest, making it the least concentrated solution.

Question 6

How much NaCl is needed to make 75 mL of a 12% (w/v)solution?

Accepted Answer

The answer of How much NaCl is needed to make...

Question 7

In general,the solubility of ________ in water decreases as temperature increases.

Accepted Answer

The solubility of gases in water decreases as temperature increases because gases become less soluble as their molecules gain kinetic energy and move more rapidly, which leads to less interaction between gas molecules and water molecules.

Question 8

How much NaCl is needed to make 50.0 mL of a 16% (w/v)solution?

Accepted Answer

To calculate the amount of NaCl needed, we need to use the formula:
% (w/v) = (mass of solute (g) / volume of solution (mL)) x 100
Rearranging the formula to solve for mass of solute:
mass of solute (g) = % (w/v) x (volume of solution (mL) / 100)
Substituting the given values:
mass of solute (g) = 16 x (50.0 / 100)
mass of solute (g) = 8.0 g of NaCl

Question 9

What is the % (w/v)concentration of a solution containing 12 grams of solute in 400 mL of solution?

Accepted Answer

The % (w/v) concentration is calculated by dividing the mass of the solute (12 grams) by the volume of the solution in mL (400 mL) and then multiplying by 100. This gives (12/400) * 100 = 3.0%.

Question 10

What is the molarity of a solution prepared by dissolving 3.50 mol NaCl in enough water to make 1.50 L of solution?

Accepted Answer

Molarity is calculated by dividing the number of moles of solute by the volume of the solution in liters. For this problem, $ \text{Molarity} = \frac{3.50 \, \text{mol}}{1.50 \, \text{L}} = 2.33 \, \text{M} $.

Question 11

How much NaOH is present in a 250.mL sample of a 5.00% (w/v)solution?

Accepted Answer

We can start by using the formula:

mass = (concentration) x (volume)

where concentration is in % (w/v), volume is in mL, and mass is in g.

Substituting the given values:

mass = (5.00%)(250 mL) = 12.5 g

Therefore, the amount of NaOH present in the sample is 12.5 g, which corresponds to choice C, 12.5 g.

Question 12

The solubility of nitrogen in water exposed to the atmosphere,where the partial pressure of nitrogen is 593 mm,is 5.3 × 10^-4 M.At the same temperature,what would be the solubility of pure nitrogen,at a pressure of 760 mm?

Accepted Answer

The solubility of a gas is directly proportional to the partial pressure of the gas above the liquid. Therefore, we can use the following equation:

Solubility1/Solubility2 = Partial pressure1/Partial pressure2

where Solubility1 is the solubility of nitrogen in water at a partial pressure of 593 mm, and Solubility2 is the solubility of pure nitrogen at a pressure of 760 mm.

Substituting the known values:

5.3 × 10^-4 / Solubility2 = 593 / 760

Solving for Solubility2:

Solubility2 = 6.8 × 10^-4 M

Therefore, the answer is B.

Question 13

How much NaCl is present in 25.0 mL of a 12.0% (w/v)solution?

Accepted Answer

A 12.0% (w/v) solution means there are 12.0 grams of NaCl per 100 mL of solution. Therefore, in 25.0 mL of solution, there would be (12.0 g/100 mL) * 25.0 mL = 3.00 g of NaCl.

Question 14

Calculate the concentration of nitrogen gas in water with a nitrogen gas at a partial pressure of 0.826 atm above it.Henry's law constant for nitrogen in water is 6.8 × 10^-4 mol/L-atm.

Accepted Answer

Using Henry's law, the concentration of a gas in a liquid is given by $C = kP$, where $C$ is the concentration, $k$ is Henry's law constant, and $P$ is the partial pressure of the gas. Substituting the given values, $C = 6.8 \times 10^{-4} \times 0.826 = 5.6 \times 10^{-4} \, \text{M}$.

Question 15

What is the % (w/v)concentration of a solution containing 8.0 grams of alcohol in 50.0 mL of solution?

Accepted Answer

The answer of What is the % (w/v)concentration of a...

Question 16

Which solution is the most concentrated? Each choice refers to the same solute and solvent.

Accepted Answer

The answer of Which solution is the most concentrated? Each...

Question 17

How much NaCl is present in a 15.0 mL sample of a 12.0% (w/v)solution?

Accepted Answer

12.0% (w/v) solution means that there are 12 grams of NaCl in 100 mL of solution.
So, in 15.0 mL of solution, the amount of NaCl would be:

(12 g NaCl / 100 mL of solution) x (15.0 mL of solution) = 1.80 g of NaCl

Therefore, the correct answer is A) 1.80 g.

Question 18

How much NaOH is present in a 75.0 mL sample of a 5.00% (w/v)solution?

Accepted Answer

A 5.00% (w/v) solution means there are 5.00 grams of NaOH per 100 mL of solution. Therefore, in 75.0 mL, there would be (5.00 g/100 mL) * 75.0 mL = 3.75 g of NaOH.

Question 19

What is the % (w/v)concentration of a solution containing 25.0 g of solute in 400.mL of solution?

Accepted Answer

First, convert the volume to liters:

400 mL = 0.400 L

Then, use the definition of % (w/v) concentration:

% (w/v) = (mass of solute (g) / volume of solution (mL)) x 100%

% (w/v) = (25.0 g / 400 mL) x 100%

% (w/v) = 6.25%

Therefore, the answer is choice C.

Question 20

How many g of NaOH is needed to make 350.mL of a 2.50% (w/v)solution?

Accepted Answer

To find the grams of NaOH needed, use the formula for weight/volume percent: (mass of solute/volume of solution) x 100 = % (w/v). Rearranging gives mass of solute = (% (w/v) x volume of solution) / 100. Substituting the given values: (2.50 x 350 mL) / 100 = 8.75 g.

Quiz 9: Solutions

Which information is necessary to determine the molarity of a solution if the chemical formula of the solute is known?

How many grams of NaOH are needed to make 750 mL of a 2.5% (w/v) solution?

What is the molarity of a solution prepared by dissolving 0.750 mol CaCl₂ in enough water to make 0.500 L of solution?

All of the statements about molarity are correct except

Which solution is the least concentrated? Each choice refers to the same solute and solvent.

How much NaCl is needed to make 75 mL of a 12% (w/v) solution?

In general,the solubility of ________ in water decreases as temperature increases.

How much NaCl is needed to make 50.0 mL of a 16% (w/v) solution?

What is the % (w/v) concentration of a solution containing 12 grams of solute in 400 mL of solution?

What is the molarity of a solution prepared by dissolving 3.50 mol NaCl in enough water to make 1.50 L of solution?

How much NaOH is present in a 250.mL sample of a 5.00% (w/v) solution?

The solubility of nitrogen in water exposed to the atmosphere,where the partial pressure of nitrogen is 593 mm,is 5.3 × 10^-4 M.At the same temperature,what would be the solubility of pure nitrogen,at a pressure of 760 mm?

How much NaCl is present in 25.0 mL of a 12.0% (w/v) solution?

Calculate the concentration of nitrogen gas in water with a nitrogen gas at a partial pressure of 0.826 atm above it.Henry's law constant for nitrogen in water is 6.8 × 10^-4 mol/L-atm.

What is the % (w/v) concentration of a solution containing 8.0 grams of alcohol in 50.0 mL of solution?

Which solution is the most concentrated? Each choice refers to the same solute and solvent.

How much NaCl is present in a 15.0 mL sample of a 12.0% (w/v) solution?

How much NaOH is present in a 75.0 mL sample of a 5.00% (w/v) solution?

What is the % (w/v) concentration of a solution containing 25.0 g of solute in 400.mL of solution?

How many g of NaOH is needed to make 350.mL of a 2.50% (w/v) solution?

Quiz 9: Solutions

Which information is necessary to determine the molarity of a solution if the chemical formula of the solute is known?

How many grams of NaOH are needed to make 750 mL of a 2.5% (w/v) solution?

What is the molarity of a solution prepared by dissolving 0.750 mol CaCl2 in enough water to make 0.500 L of solution?

All of the statements about molarity are correct except

Which solution is the least concentrated? Each choice refers to the same solute and solvent.

How much NaCl is needed to make 75 mL of a 12% (w/v) solution?

In general,the solubility of ________ in water decreases as temperature increases.

How much NaCl is needed to make 50.0 mL of a 16% (w/v) solution?

What is the % (w/v) concentration of a solution containing 12 grams of solute in 400 mL of solution?

What is the molarity of a solution prepared by dissolving 3.50 mol NaCl in enough water to make 1.50 L of solution?

How much NaOH is present in a 250.mL sample of a 5.00% (w/v) solution?

The solubility of nitrogen in water exposed to the atmosphere,where the partial pressure of nitrogen is 593 mm,is 5.3 × 10-4 M.At the same temperature,what would be the solubility of pure nitrogen,at a pressure of 760 mm?

How much NaCl is present in 25.0 mL of a 12.0% (w/v) solution?

Calculate the concentration of nitrogen gas in water with a nitrogen gas at a partial pressure of 0.826 atm above it.Henry's law constant for nitrogen in water is 6.8 × 10-4 mol/L-atm.

What is the % (w/v) concentration of a solution containing 8.0 grams of alcohol in 50.0 mL of solution?

Which solution is the most concentrated? Each choice refers to the same solute and solvent.

How much NaCl is present in a 15.0 mL sample of a 12.0% (w/v) solution?

How much NaOH is present in a 75.0 mL sample of a 5.00% (w/v) solution?

What is the % (w/v) concentration of a solution containing 25.0 g of solute in 400.mL of solution?

How many g of NaOH is needed to make 350.mL of a 2.50% (w/v) solution?

What is the molarity of a solution prepared by dissolving 0.750 mol CaCl₂ in enough water to make 0.500 L of solution?

The solubility of nitrogen in water exposed to the atmosphere,where the partial pressure of nitrogen is 593 mm,is 5.3 × 10^-4 M.At the same temperature,what would be the solubility of pure nitrogen,at a pressure of 760 mm?

Calculate the concentration of nitrogen gas in water with a nitrogen gas at a partial pressure of 0.826 atm above it.Henry's law constant for nitrogen in water is 6.8 × 10^-4 mol/L-atm.