I need help with my chem hw.?

1. Manganese makes up 1.3 ´ 10–4 percent by mass of the elements found in a normal healthy body. How many grams of manganese would be found in the body of a person weighing 183 lb? (2.2 lb = 1.0 kg)

A) 1100 g

B) 0.11 g

C) 11 g

D) 0.24 g

E) none of these is correct

2. In 1928, rhenium cost $10,000/kg. It now costs $40/troy ounce. What is the present cost of a gram of rhenium? (1 troy ounce = 31.10 g)

A) less than $1.00

B) between $1.00 and $10

C) between $10 and $50

D) between $50 and $100

E) over $100

3. What data would you need to estimate the money you would spend on gas to drive your car from Los Angeles to Chicago? Provide a sample calculation.

4. In a recent accident some drums of uranium hexafluoride were lost in the English Channel. The melting point of uranium hexafluoride is 64.5°C. What is the melting point of uranium hexafluoride on the Fahrenheit scale? (TF = TC ´ (9°F/5°C) + 32°F)

A) 1.35°F

B) 82.3°F

C) 116°F

D) 122°F

E) 148°F

5. The melting point of indium is 156.2°C. At 323°F, what is the physical state of indium?

(TF = TC ´ (9°F/5°C) + 32°F)

A) solid

B) liquid

C) gas

D) not enough information

E) At 323°F, the indium is partially solid and partially liquid; there is an equilibrium between the two states.

6. Convert: –40.0 °C = ____ °F. (TF = TC ´ (9°F/5°C) + 32°F)

7. A monolayer containing 3.20 ´ 10–6 g of oleic acid has an area of 20.0 cm2. The density of oleic acid is 0.895 g/mL. What is the thickness of the monolayer (the length of an oleic acid molecule)?

A) 2.86 ´ 10–6 cm

B) 3.58 ´ 10–6 cm

C) 5.59 ´ 10–6 cm

D) 1.79 ´ 10–7 cm

E) 1.43 ´ 10–7 cm

8. The density of gasoline is 0.7025 g/mL at 20°C. When gasoline is added to water:

A) it will float on top.

B) it will sink to the bottom.

C) it will mix so you can't see it.

D) the mixture will improve the running of the motor.

E) none of these things will happen.

9. The density of a liquid is determined by successively weighing 25, 50, 75, 100, and 125 mL of the liquid in a 250-mL beaker. If volume of liquid is plotted along the horizontal axis, and total mass of beaker plus liquid is plotted on the vertical axis:

A) the x, or horizontal, intercept is the negative value of the weight of the beaker.

B) the y, or vertical, intercept is the weight of the empty beaker.

C) the slope of the line is 1.0.

D) the line will pass through the origin.

E) the slope of the line is independent of the identity of the liquid.

10. The boiling of water is a

A) physical change because the water merely disappears.

B) physical change because the gaseous water is chemically the same as the liquid.

C) chemical change because heat is needed for the process to occur.

D) chemical change because a gas (steam) is given off.

E) chemical and physical damage.