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Chemistry Online----------------------
-----------------Quiz 9---------------------

Name______________

Dr. Walt Volland
50 point

 

Short answer essay questions

 

 

1. 5 points

What makes H2O and CH3CH2OH completely miscible?

 

2. 8 points

How does the temperature of a solvent like water influence the solubility of a dissolved gas like CO2?

The animation below shows a gas and its solution at equilibrium. What will happen to the gas pressure in the gas state, if the volume of the space is reduced from 100 mL to 67 mL? What happens to the number of dissolved gas molecules at this new pressure?
 

3. 5 points

Write the formulas for the solute ions in a 0.034 M Al(OH)3 aqueous solution. Give the molarity for each ion. Show set ups for the calculations.

 

 

4. 3 BONUS POINTS What do you think is the most important topic in this chapter? Briefly justify your choice.

 

 

Multiple choice questions (3 points each 30 points possible)

 

1. Which of the following is a nonelectrolyte?

a.

HCl(aq)

b.

NaOH

c.

H2O

d.

LiCl
 

2. What is the molarity of the solution that results from mixing 3.0 mols of HBr(g) and enough water to make 1200 mL of solution? Set ups are shown

1 mol HBr = 81 g HBr

a.

0.0025

b.

(3.0) / (1.2)

c.

3.0 ( 1.2)/ 81

d.

(81)(3.0)/1.2

e.

(3.0)/(81)(1.2)

 

3. How many mols of NaOH are in 300 milliliters of 0.25 M NaOH ? Set ups are shown

1 mol NaOH = 40 g NaOH

a.

300 / .25

b.

(300/1 ) (1/ 1000) ( 0.25 )

c.

0.25 / .300

d.

40 ( 0.25 ) ( 1/ 0.300)

 

4. What is the molarity of a mixture of 3.0 mols of KOH and enough water to make a mixture with a volume of 0.800 liters? Set ups are shown

1 mol KOH = 56 g KOH

a.

3.0 / 800

b.

800 / 3.0

c.

3.0 / .800

d.

56 (3.0 ) ( 0.800 )

 

5. What is the molarity when 240 ml of 8.0 M HF solution is added to enough water to make a total mixture of 1.20 liter ? Set ups are shown

a.

1.20 ( 8.0 / .240)

b.

8.0 ( 1.20 / 0.240)

c.

1.20 ( .240 / 8.0 )

d.

1.20 (240 / 8.0)

e.

8.0 ( .240 / 1.20 )

6. How many grams of NH3 are in 300 ml of a 6.0 M NH3 solution? Set ups are shown

1 mol NH3 = 17 g NH3

a.

17/ 0.300( 6 )

b.

17 ( .300 )

c.

6 ( 0.300) 17

d.

17

e.

17 ( 6 ) / .300

7. Which of the following is expected to be soluble in H2O?

a.

CH4

b.

CH3OCH3

c.

SiO2

d.

CH3SCH3

e.

HCl

8. Henry's law can be used to concentrations for solutions of water and

a.

NaNO3(s)

b.

CH3CH2OH(l)

c.

NO2(g)

d.

HC2H3O2(l)

9. Solutions transmit light and appear to be transparent.

a.

True

b.

False

10. Which of the following will produce a higher dissolved oxygen concentration?

a.

water and oxygen at a pressure of 0.05 atm at 20oC

b.

water and oxygen at a pressure of 0.05 atm at 40oC

c.

water and oxygen at a pressure of 0.15 atm at 10oC

d.

water and oxygen at a pressure of 0.15 atm at 40oC

 

 

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