Highlander Help

### Resources:

Have you found videos, websites, or explanations that helped you understand this chapter? Let us know and we'll add them to "Resources" part of this page for other students to use.

## Answer Explanations Coming Soon!

### Question 1

What volume (in mL) of 12 M HCI solution is required to prepare exactly 500. mL of a 0.67 M HCI solution?

### Explanation

M1V1=M2V2

(12 M ) (V1) = (0.67 M) (500 mL)

V1 = (0.67 M)(500 mL) / (12M)

V1 = 27.91

### Question 2

What is the molar mass of an ideal gas if a 0.800 g sample of this gas occupies a volume of 200. mL at 50.0 oC and 720. mm Hg?

Select one:

### Explanation

P = 720 mmHg/ 760 = 0. 947 atm

PV = nRT

n = PV/ RT

n = (0.947 x 0.2L) / ( .08206 *323) = 0.007 mol CaCO3

0.007 mol CaCO3 x ( 1 mol CO2/ 1 mol CaO ) = 0.007 mol

0.800 g / 0.007 mol = 111.9 g/mol

### Question 3

Which set of temperature and pressure conditions will cause a gas to exhibit the LEAST deviation from ideal gas behavior?

Select one:

### Explanation

High temperature and low pressure exhibits the least deviation from ideal gas

### Question 4

What is the molarity of a solution made by dissolving 3.49 g of sodium acetate in water and diluting to 750. mL? (molar mass NaC2H3O2 is 82.0 g/mol.)

### Explanation

3.49g x ( 1 mol / 82.08 g) = .0425 mol

0.0425 mol / .75 L = 0.0567 mol / L

### Question 5

An open-ended mercury manometer is used to measure the pressure exerted by a trapped gas as shown in the figure. Atmospheric pressure is 750. mmHg. What is the pressure (in mmHg or torr) of the trapped gas if h =3 cm?

### Explanation

h = 3 cm = 30 mm

P total = 750 mmHg + 30 mmHg = 780 mmHg

Select one:

### Explanation

A solution is a mixture where solutes and solvents are equally mixed.

### Question 7

Which substance meets the requirements: crsytalline solid; brittle; poor electrical conductor in the solid state; good conductor in liquid phase; melts at high temperature?

Select one:

### Explanation

An ionic compound conducts electricity in liquid (dissolves) and solid. Also it melts at high temperature.

### Question 8

The boiling point of an impure compound is generally

Select one:

### Explanation

An impure compound usually has extra solutes that increases intermolecular forces between solutes and solvent

### Question 9

Given the cooling curve of one gram of a pure liquid, the length of the line BC depends on

Select one:

### Explanation

Line BC has a flat slope this means temp is not changing. Instead, the object is going through a phase change. In this case the object is going from solid to liquid (melting)

### Question 10

Starting at point A and ending at point F, which of the following processes requires the most energy?

Select one:

### Question 11

Which phase has the largest specific heat? (Hint, how are the slope and specific heat related?)

Select one:

### Explanation

liquid phase has the steepest slope so it has the largest specific heat.

### Question 12

Copper crystallizes in a face-centered cubic lattice. What is the mass of one unit cell? Report your answer in grams.

Select one:

NO POINTS

### Question 13

Metal M crystallizes in a face-centered cubic lattice. If the edge of the unit cell is 200 pm, what is the radius of a metal M atom (in pm)?

Select one:

NO POINTS

### Question 14

A 500. mL gas sample is collected over water at a pressure of 740 mmHg and 60 °C. What is the volume of the dry gas at STP? (STP = 1 atm and 0 °C.) Vapor pressure of water at 60. °C is 149 mmHg.

Select one:

### Explanation

740 mmHg - 149 mmHg = 591 mmHg

PV= nRT

PV/ RT = PV/ RT

(.778) (.5) / (.08206) (333) =  (1) (V) / (.08206)(273)

V =  (.778) (.5) (.08206)(273) / (.08206) (333) (1) = 320mL

### Question 15

Which point corresponds to the critical temperature and pressure?

Select one:

### Question 16

Starting at point A and lowering the pressure at constant temperature is best described by

Select one:

### Question 17

Which of the following conditions are possible at point C?

Select one:

### Explanation

Triple Point is where all phases exist (solid, liquid, gas)

### Question 18

Which of the following statements is NOT correct?

Select one:

### Explanation

At the critical point the supercritical fluid does not phase change

### Question 19

Which factor affects the vapor pressure of a liquid?

Select one:

### Explanation

• vapor pressure of a liquid varies with its temperature
• As the temperature of a liquid or solid increases its vapor pressure also increases.
• Vapor pressure decreases as temperature decreases.

### Question 20

The graph shows how the vapor pressure of a liquid Changes with temperature. At 500 torr, what is the boiling temperature?

Select one:

### Explanation

Just look at the graph

### Question 21

What is the vapor pressure of a solution with a benzene to octane molar ratio of 1:3 at 50 °C? At 50 °C, the vapor Pressure of pure benzene and octane are respectively 280 mmHg and 400 mmHg.

Select one:

### Explanation

Your content goes here...

### Question 22

A particular solid is soft, a poor conductor of heat and electricity, and has a low melting point. Generally, such a solid is classified as

Select one:

### Explanation

Your content goes here...

### Question 23

Which solution is the most concentrated.

Select one:

### Explanation

High concentration: more solute particles less water molecules