CHM Chapter 13 Review

What volume of 9.00 M nitric acid is needed to make 6.50 L of 1.25 M solution?

(9 M) (V1) = (1.25 M) (6.5 L) V1 = .903 L, or 903 mL

When an ionic compound dissolves in water:

- the negative end of water dipoles attract positive ions - the positive end of water dipoles attract the negative ions - the solvent-solute attractive forces overcome the solute-solute attractions

What is the freezing point of a 0.75 m aqueous solution of sucrose (C12H22O11)? (Kf for water is 1.86 °C · kg/mol solute.)

-1.4 C

What is the freezing point of a 0.75 m aqueous solution of calcium chloride? (Kf = 1.86 °C · kg/mol solute)

-4.2 C

A solution contains 100.0 g water, 10.0 g NaCl, and 15.0 g methanol. What is the mass percent of methanol in the solution?

1) 100 g + 10 g + 15 g= 125 g 2) 15 g /125 g= .12 3) .12 X 100= 12%

Calculate the mass percent of a NaCl solution prepared by mixing 21.0 g NaCl with 125.0 mL of pure water.

1) 125 g + 21 g= 146 g 2) 21 g / 146 g= .1438 3) .1438 X 100= 14.4 %

What is the mass percent of a solution prepared by dissolving 18.9 grams of solid into 39.5 grams of water?

1) 18.9 g + 39.5 g= 58.4 2) 18.9/ 58.4 g= .324 3) .324 X 100= 32.4%

What volume of 0.100 M sodium hydroxide is required to completely neutralize 50.0 mL of 0.100 M phosphoric acid?

150 mL

How many grams of KNO3 are in a 125 g solution containing 14.5% solute?

18.1 g

The solubility of gases in water:

decreases with increasing temp

What happens to the solubility of a gas when the temperature increases?

solubility decreases

What happens to the solubility of a gas when the pressure above a liquid increases?

solubility increases

The tragedy at Lake Nyos in Cameroon, West Africa, was caused by:

the release of excessive amounts of carbon dioxide that had been dissolved in the water at the bottom of the lake.

In order for a solute to dissolve in solution:

the solute-solvent forces must be greater than the solute-solute forces

The solubility of Pb(NO3)2 is 55 grams per 100 g H2O at 20°C. Which term would properly describe a solution where 44 grams of Pb(NO3)2 is added to 100 grams of water at this temperature?

unsaturated

Consider the reaction: K2S(aq)+Co(NO3)2(aq)→ 2KNO3(aq)+CoS(s) a) What volume of 0.205 M K2S solution is required to completely react with 155 mL of 0.150 M Co(NO3)2?

1) .155 L X .150 M= 0.02325 2) 0.0235 X 1 L/ .205 M= .113 L

How many grams of LiF would be present in 575 mL of 0.750 M LiF solution?

1) 0.750 M X .575 L= .43125 mol 2) .43125 mol X 25.93= 11.2 g

Calculate the mass percent of 2.50 moles of NaOH in 0.900 L of water at 25 °C. (The density of water is 1.00 g/mL at 25 °C)

10%

To the nearest degree, calculate the boiling point of an aqueous solution containing 36 g NaCl in 100. g of water. (Kb = 0.512 °C · kg/mol solute)

106 C

What is the molarity of a KNO3 solution containing 2.45 mol KNO3 in 500. mL of solution?

4.90 M

What mass of hydrogen gas will be formed when 125 mL of 0.500 M hydrochloric acid is reacted according to the following equation? Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq)

0.0630 g

What are the ion concentrations in a 0.12 M solution of AlCl3?

0.12 M Al3+ ions and 0.36 M Cl− ions

A 0.15 M solution of BaCl2 contains:

0.15 M Ba2+ ions and 0.30 M Cl- ions

Determine the molar concentrations of Ca2+ and Cl- in a 0.38 M calcium chloride solution.

0.19 M Ca2+ and 0.38 M Cl-

Which of the following NaCl solutions has the highest concentration of NaCl

0.25 mol NaCl in 200 mL of solution

If the solubility of potassium nitrate at 20 °C is 37 g per 100 g of water, how many grams of the compound will dissolve in 1.0 mL of water?

0.37 g

Calculate the molality of a solution containing 0.455 mol of sucrose and 1.00 L of water at a temperature at which the water has a density of 1.00 g/m

0.455 m

What mass (in grams) of fructose (C6H12O6) is contained in 125 mL of a 0.500 M fructose solution?

1) .500 M X .125 L= .0625 2) C6H12O6= 72.1 + 12.096 + 95.994= 180.2 3) 0.0625 x 180.2= 11.3 g

A saline solution contains 1.7% of NaCl by mass. How much NaCl is present in 66.3 g of this solution?

1) 1.7% --> 1.7 g 1.7 g/ 100g= 0.017 g 2) 0.017 X 66.3 g= 1.127 * Rounded: 1.1*

How many grams of KCl are needed to make 50.0 mL of 2.45 M KCl?

1) 2.45 M X .05 L= .1225 2) .1225 X 74.55 g = 9.13 g

We dissolve 2.45 g of sugar in 200.0 g water. What is the mass percent of sugar in the solution?

1) 2.45 g/ 200 g= 1.23%

What volume (L) of 0.750 M KCl solution contains 25.0 g of KCl?

1) 25 g/ 74.55 = 0.335 mol 2) .335 mol/ .750= .447

What is the mass percent of an ammonium carbonate solution prepared by dissolving 33.2 grams of solid into 39.5 grams of water?

1) 33.2 + 39.5= 72.7 g 2) 33.2 g/ 72.7 g= .457 3) .457 X 100= 45.7%

How many moles of NaF are in 34.2 grams of a 45.5% by mass NaF solution?

1) 34.2 g X 45.5% / 100= 15.6 2) 15.6 (1 mol/ 41.9887) * 0.371 mol

What is the final concentration of a solution prepared by diluting 35.0 mL of 12.0 M HCl to a final volume of 1.20 L?

1) 35 ml has 12 x 35/1000 mol = 0.42 mol in 1.2 dm3 2) 0.42 x 1000/1200 = 0.35 mol/dm3

What is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water?

1) 42 g/mol X .64 mol= 26.88 2) (26.88/ 63.50) X 100= 42.3%

How many moles of KCl are present in 95.3 mL of 2.10 M KCl?

1) 95.3 mL --> L - 95.3 mL/1000= .0953 2) 2.10 M X .0953 L= .200

A 30.0 mL sample of an unknown HClO4 solution requires 50.3 mL of 0.102 M NaOH for complete neutralization.. a) What was the concentration of the unknown HClO4 solution? The neutralization reaction is: HClO4(aq)+NaOH(aq)→H2O(l)+NaClO4(aq)

1) Convert mL to L 50.3 mL --> 0.0503 L 30.0 mL --> 0.03 L 2) 0.0503 L X .102 M= .0051 3) 0.0051 / 0.03 L= .17 M

Calculate the molarity of a KCl solution made by dissolving 12.3 g of KCl in a total volume of 500. mL.

1) KCl= 74.45 - 12.3 g/ 74.45 g= .165 2) n/V - .165/ .500 L = 0.330

How many grams of KCl are present in 85.0 mL of 2.10 M KCl?

1) mol KCl: (0.0850 L X 2.10 M)= .1785 mol 2) Molar Mass KCl= 74.55 3) Mass KCl: (.1785 mol) X (74.55) = 13.3 g

Which one of the following aqueous solutions would have the higher concentration of K+ (aq) ions? (Assume total solubility in water.)

1.0 M K3PO4

What is the molarity of NaOH in a solution containing 40.0g of NaOH in 750. mL of solution?

1.33 M

35.0 mL of 0.155 M lead(II) nitrate and 45.0 mL of 0.287 M potassium chloride are mixed. How much precipitate is produced?

1.51 g

What is the molality of an aqueous ethylene glycol solution whose boiling point elevation is 0.87 °C? (Kb for water is 0.512 °C · kg/mol solute.

1.7 m

Calculate the volume of 0.250 M solution made by dissolving 5.56 g of solid magnesium chloride in water.

234 mL

How many mL of 0.218 M sodium sulfate react with exactly 25.34 mL of 0.113 M BaCl2 given the reaction: BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq)

25.34 x 0.113 = X x 0.218 X = 13.13 mL Na2SO4

What molarity should the stock solution be if you want to dilute 25.0 mL to 2.00 L and have the final concentration be 0.103 M?

25X/1000 = 2(0.103) 25X = 206 X = 8.24 M

How much water would you ADD to 175 mL of 6.00 M hydrochloric acid to prepare a 2.00 M solution of this acid?

350 mL

A sugar solution contains 19% sucrose by mass. What is the mass of the solution if it contains 78.01 g sucrose

410 g

If the solubility of sodium acetate (Molar mass = 82 g/mol) is 76 grams per 100 grams of water, which of the following solutions would be considered supersaturated?

5.5 moles of sodium acetate dissolved in 500 mL of water

If the solubility of sodium chloride is 36 grams per 100 grams of water, which of the following solutions would be considered unsaturated?

5.8 mol of NaCl dissolved in 1 L of water

How would you safely prepare 500. mL of 1.00 M H2SO4 solution from a 12.4 M H2SO4 stock solution? Select the best answer

Add 40.3 mL of 12.4 H2SO4 to 459.7 mL of water

Suppose a vodka martini contains 30% alcohol with the remaining portion of the drink composed of water. What is the solute in this type of martini?

Alcohol= solute

Which of the following is NOT an example of a colligative property?

Boiling point depression

Examples of solutions...

Bronze, soda, homogenized milk, sea water

Which solvent would be most suitable to remove grease from an object?

C8H18

In theory, which of the following would have the greatest solubility in gasoline (C8H18)?

CH3CH2CH3

What is the molarity of a solution prepared by dissolving 54.3 g of Ca(NO3)2 into 355 mL of water?

Ca(NO3)2= 164 g 1) 54.3 g/ 164 g= 0.331 mol 2) 0.331 mol/ .355 L= 0.932 M

Which of the following substances is NOT a solution?

Copper - Cu is a pure element Oxygen - O is a pure element

Which of the following would be the poorest conductor of electricity?

H2O (l)

Which compound below forms an electrolyte solution when dissolved in water?

KOH

What volume of 12.0 M HCl is required to make 75.0 mL of 3.50 M HCl?

M1V1 = M2V2 12.0*V1 = 3.50*75.0 V1 = 3.50*75.0/12.0 V1 = 21.875ml

To what volume should you dilute 55 mL of a 10.5 M H2SO4 solution to obtain a 1.95 M H2SO4 solution?

M1V1=M2V2 1) (10.5)(55)/ 1.95 M= 300 mL

What is the final concentration (M) of a solution prepared by diluting 50.0 mL of a 6.00 M KCl solution to a volume of 0.250 L?

M1V1=M2V2 1) (6 M) (.05 L)= X (.025 L) 2) .3/ .025= 1.20

What is the concentration of sodium chloride in the final solution if 25.34 mL of 0.113 M BaCl2 completely reacts and the total volume of the reaction is 110.4 mL, given the reaction: BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq)

Moles BaCl2 = 0.113 mol/L X 0.02534 L = 2.86X10^-3 mol BaCl2 Moles NaCl = 2.86 X 10^-3 mol BaCl2 X (2 mol NaCl/1 mol BaCl2) = 5.73 X 10^-3 mol NaCl Concentration NaCl = 5.73X10^-3 mol / 0.1104 L = 0.0519 mol/L NaCl

Which of these compounds would you expect to be least soluble in water?

N2

Which of the following compounds is a strong electrolyte?

NaC2O2

What is the solute when 10 g of NaCl is dissolved in 100 mL of water?

NaCl

What is the molarity of a solution prepared by dissolving 10.7 g NaI in 0.250 L?

NaI= 149.89 g 1) 10.7 g / 149.89 g= 0.071 mol 2) (0.071 ) / (.250 L) = 0.286

Oftentimes solubility of a compound limits the concentration of the solution that can be prepared. Use the solubility data given with each compound shown below to determine which compound would allow the preparation of a 10.0 Molar solution.

NaNO3 (solubility = 89.0 g/100 g H2O)

A 90.0 g sample of NaOH is dissolved in water and the solution is diluted to give a final volume of 3.00 liters. The molarity of the final solution is ________.

NaOH = 40 g/mol 90 g NaOH = 90/40 moles = 2.25 moles / 3L = 2.25/3 moles/1 L = 0.75 M

How is the solubility of a gas affected by the temperature of the solution

Solubility increases with decreasing temp

Which type of interaction must be strong in order to dissolve a salt?

Solvent-solute

A solution is saturated in both nitrogen gas (N2) and sodium iodide (NaI) at 50°C. When the solution is cooled to 25°C, which of the following is most likely to occur?

Some sodium iodide will precipitate out of the solution

What happens during cooling?

The excess substance will recrystallize

After you have completed the task of diluting a solution, which statement below must be TRUE?

The new solution has more volume but has a lower concentration than before.

The oxygen in the air we breath is classified as:

The solute in a homogeneous gas mixture

If you add 4.00 mL of pure water to 6.00 mL of 0.750 M NaCl solution, what is the concentration of sodium chloride in the diluted solution?

V1C1/V2 = C2 (.75*6)/10 = .45

Given that you wished to use exactly 0.325 mole of NaCl to prepare a 2.50 M NaCl solution, how many milliliters of solution must you prepare?

Volume: 0.325 mol/ 2.50 mol= .130 L 2) .130 L --> mL * 130 mL

Which of the following substances is an example of a solution?

Wine

An ethylene glycol solution contains 22.2 g of ethylene glycol (C2H6O2) in 80.4 mL of water. a) Calculate the freezing point of the solution. Assume a density of 10.0 g/mL for water) b) Calculate the boiling point of the solution.

a) 1. 80.4 --> 0.0804 Kg 2. mol C2H6O2: 22.2 g / 62.068= .3577 3. Molarity: .3577/ .0804= 4.45 4) Delta T: 4.45 X 1.86= 8.28 * -8.28 C* b) 1. Molarity: .3577/.0804= 4.45 2. 4.45 X .512= 2.28 3. 100 C + 2.28 C= 102.28 *102.3 C*

Determine the concentration of NO−3 in each aqueous solution... a) 0.14 M KNO3 b) 0.14 M Ca(NO3)2 c) 0.14 M Cr(NO3)2

a) 1 mol of KNO3= 1 mol of KNO3 * 0.14 M b) 1 mol of KNO3= 2 mol of Ca(NO3)2 * 0.14 X 2= 0.28 M c) 1 mol of KNO3= 3 mol of Cr(NO3)3 * 0.14 X 3= 0.42 M

Calculate molarity... a) 1.54 mol of LiCl in 30 L solution b) 0.110 mol of LiNO3 in 6.2 L of solution c) 0.0308 mol of glucose in 75.4 mL of solution

a) 1.54 mol/ 30 L= 0.051 M b) 0.110 mol/ 6.2 L= 0.018 M or 1.8 X 10^-2 M c) 75.4 mL --> L 1. 75.4 mL/ 1000= 0.0754 2. 0.0308 mol/ 0.0754L= .408 M

Identify the solute and solvent in each equation.... a) 80 proof vodka (40% ethyl alcohol) b) Oxygenated water c) Antifreeze (ethylene glycol and water)

a) Water is the solvent and ethyl alcohol is the solute b) Water is solvent and oxygen is solute c) water is solvent and ethylene glycol is solute

Which of the following mixtures are solutions? a) Carbon dioxide and water mixture b) a blueberry muffin c) a brass buckle d) air

a, c, and d

When preparing sodium hydroxide solution, it is best to use water that does not contain any dissolved carbon dioxide as it reacts with the sodium hydroxide. Removing the carbon dioxide can be accomplished by:

boiling the water

A supersaturated solution....

contains more dissolved solute than the solubility limit at that temp

Solubility of gases in water:

increases with increasing pressure above solution

The solubility of solids in water:

increases with increasing temp and are independent of pressure above solution

The solubility of a gas in a liquid can always be increased by:

increasing the pressure of the gas above the solvent

How many grams of barium sulfate are produced if 25.34 mL of 0.113 M BaCl2 completely react given the reaction: BaCL2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq)

moles BaCl2 = 0.02534 L x 0.1133 M=0.002871 = moles BaSO4 mass BaSO4 = 0.002871 mol x 233.389 g/mol= 0.6701 g

The molarity of a solution is defined as the number of....

moles of solute per liter of solution

You need to prepare 2.00 L of 0.100 M Na2CO3 solution. The best procedure is to weigh out:

moles= c X V 1) .100 M X 2.00 L/ .200 M mass= moles X molar mass 2) .200 M X 105.99 g= 21.2 g Na2CO3 * 21.2 g Na2CO3 and add water until the final solution has a volume of 2.00 L.

Calculate the molarity of a KCl solution prepared by dissolving 0.321 moles of KCl in 250. mL of water.

n/v= molarity 1) 0.321 mol/ .250 L= 1.28 KCl

Hexane, a non-polar solvent, will dissolve which of the following substances?

oil

If you prepare a solution by adding sufficient amount of solute so that after heating and cooling the solution there is a visible amount of solid solute left in the bottom of the beaker, the solution would be considered ________.

saturated

A red blood cell with a concentration of 0.9 g NaCl per 100 mL of solution is placed into a 2.0 g NaCl per 100 mL solution. The cell

shrinks