Reactions in Solutions, Calculating Solution Concentration, and Colligative Unit Test Review and Test 96%

The molality of a solution that is made by dissolving a certain mass of benzene in 20.6 g of carbon tetrachloride is 0.529 m. How many moles of benzene were dissolved?

0.0109 mol

A 150 mL sample of hydrochloric acid (HCl) completely reacted with 60.0 mL of a 0.100 M NaOH solution. The equation for the reaction is given below. HCl + NaOH -> NaCl + H2O What was the original concentration of the HCl solution?

0.040 M

What is the molality of a solution that is obtained by dissolving 2.922 g of NaCl into 1000.0 g of water if the molar mass of NaCl is 58.44 g/mol?

0.05000 m

The molality of a solution that is made by dissolving a certain mass of ethanol in 85.4 g of water is 0.950 m. How many moles of ethanol were dissolved?

0.0811 mol

A 125 mL aqueous solution contains 1.86 x 10-5 g of potassium chloride and has a density of 1.02 g/mL. What is the concentration in ppm?

0.146 ppm

The molar mass of KCl is 74.55 g/mol. If 8.45 g KCl are dissolved in 0.750 L of solution, what is the molarity of the solution?

0.151 M

A solution is made by dissolving 373.5 g of Pb(NO3)2 (molar mass: 331.2 g/mol) in 2.00 × 103 g of water. What is the molality of the solution?

0.564 m

A solution containing 1.15 mol benzene dissolved in carbon tetrachloride has a concentration of 0.86 m. How many kilograms of carbon tetrachloride must the solution contain?

1.3 kg

A 250-mL aqueous solution contains 1.56 mc025-1.jpg 10-5 g of methanol and has a density of 1.03 g/mL. What is the concentration in ppm?

1.5 mc025-4.jpg 10-5 ppm

What mass of solid that has a molar mass of 46.0 g/mol should be added to 150.0 g of benzene to raise the boiling point of benzene by 6.28°C? (The boiling point elevation constant of benzene is 2.53°C•kg/mol.)

17.1 g

A solution is made by dissolving 0.611 mol of NaCl in 250 g of water. If the molar mass of NaCl is 58.44 g/mol, what is the molality of the solution?

2.4 m

In a group assignment, students are required to fill 10 beakers with 0.720 M CaCl2. If the molar mass of CaCl2 is 110.98 g/mol and each beaker must have 250. mL of solution, what mass of CaCl2 would be used?

200 g

A chemist dilutes a 1.0 mL sample of 2.0 M KNO3 by adding water to it. If the concentration of the solution that is obtained is 0.0080 M, what is its volume?

250 mL

Given that the molar mass of NaCl is 58.44 g/mol, what is the molarity of a solution that contains 87.75 g of NaCl in 500. mL of solution?

3.00 M

The molality of a solution that was made by dissolving NaCl in 1.5 kg of water is 0.40 m. If the molar mass of NaCl is 58.44 g/mol, what is the mass of NaCl that was dissolved?

35 g

A teacher wants to prepare a 0.010 ppm solution of arsenic pentoxide in the laboratory for calibrating a water quality testing system. If the teacher uses 500.0 mL of water (which has a mass of 500.0 g), what mass of arsenic pentoxide should the teacher mix to get the required solution?

5.0 mc016-4.jpg 10-6 g

A 1.00 L volume of HCl reacted completely with 2.00 L of 1.50 M Ca(OH)2 according to the balanced chemical equation below. 2HCl + Ca(OH)2 -> CaCl2 + 2H2O What was the molarity of the HCl solution?

6.00 M

What mass of solid that has a molar mass 89.0 g/mol should be added to 100.0 g of benzene to raise the boiling point of benzene by 2.42°C? (The boiling point elevation constant of benzene is 2.53°C•kg/mol.)

8.52 g

A government laboratory wants to determine whether water in a certain city has any traces of fluoride and whether the concentration exceeds the recommended 4.00 ppm. A 5.00-g sample of this water is found to have 0.152 mg of fluoride. Should the water be declared safe for drinking?

A. 30.4 ppm > 4 ppm, unsafe to drink

Which statement best describes the process of making a solution by diluting a stock solution?

Add more solvent to decrease the concentration.

What is the relationship between the concentration of particles in a solution and the solution's vapor pressure?

As solute concentration increases, vapor pressure decreases.

Which reaction will produce a solutionWhich reaction will produce a solution that does not conduct electricity? that does not conduct electricity?

CH3OH(l) -> CH3OH(aq)

Which of the following is an electrolyte?

Ca(NO3)2

Which substance will most likely dissociate when it is dissolved in water?

CaCl2

Consider the reaction below. Fe(s) + CuSO4(aq) -> Cu(s) + FeSO4(aq) Which reactant is a substance that is dissolved in solution?

CuSO4

Saline is a solution that contains a certain amount of NaCl and is designed to have the same osmotic pressure as normal blood cells. Doctors often give saline to patients who have lost blood. Which of the following explains why glucose of the same molality cannot attain the same effect as saline?

Each formula unit of NaCl will give two particles because of ionization, but each molecule of glucose dissolves to give only one particle. Osmotic pressure for glucose will be lower than is required.

Which of the following substances will cause the greatest temperature change if the same amount of each substance is added to 1.0 kg of water?

FeCl3

Consider the equation below. Mg(s) + 2HCl(aq) mc008-1.jpg MgCl2(aq) + H2(g) Which compound is the gas in this chemical reaction?

H2

A number of beakers have different concentrations of a solution. Which statement best describes the most concentrated solution?

It has the most solute for a given volume.

Which represents a double replacement reaction and would occur?

Na2CO3(aq) + CaCl2(aq)-> 2NaCl(aq) + CaCO3(s)

Which solute, an electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water?

The electrolyte does because it dissociates into ions.

A student stirs 2 tablespoons of honey into a glass of water. How will the addition of honey affect the water's colligative properties?

The water's osmotic pressure will increase, and its vapor pressure will decrease.

Shown below is an ion from a salt molecule. mc005-1.jpg Which statement best explains the event?

This is hydration, which occurs during dissociation.

The table shows the characteristics of four substances after they are placed in water. Which compound is most likely the strongest electrolyte?

Y

Which term refers to the process by which ions that have entered solution are kept in solution?

hydration

In a coffee shop, the following coffee samples are prepared for customers. i. 10 g of sugar added to 100 g of coffee ii. 10 g of sugar added to 200 g of coffee iii. 4 g of sugar added to 200 g of coffee iv. 4 g of sugar added to 100 g of coffee Based on the amount of sugar added, which sequence ranks the coffee from the sweetest coffee to the least-sweet coffee?

i, ii, iv, iii

Which best defines concentration?

ratio that describes the amount of solute divided by the amount of solvent or solution

Which of the following best explains freezing point depression?

the decrease in the freezing point of a solution as a function of the number of particles that are dissolved in the solution

The osmotic pressure of a solution increases as

the number of particles of solute in the solution increases.

Nonelectrolytes fail to ionize or dissociate in water because

they are very strongly bonded to each other.