Chemistry Answers

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Red blood cells are placed into pure water. Which of the following statements is true?
A) water molecules flow out of the red blood cells, causing them to collapse
B) water flows into the red blood cells, causing them to swell and burst
C) the osmotic pressure of the cell contents increases, causing the cells to burst
D) the osmotic pressure inside the cells equals the osmotic pressure outside

If the Earth's ozone (O3) layer has a total volume of 1.00 x 1020 km3, a partial pressure of 1.6 x 10-9 atm, and a average temperature of 230K, how many ozone molecules are in the Earth's ozone layer?
A) 2.3 x 1035 molecules
B) 5.1 x 1035 molecules
C) 2.3 x 1045 molecules
D) 5.1 x 1045 molecules

For the process of dissolving a solid in a liquid, which of the following statements is true?
A) ΔHsoln is always negative and ΔSsoln is usually positive
B) ΔHsoln is always positive and ΔSsoln is usually negative
C) ΔHsoln is either positive or negative and ΔSsoln is usually positive
D) ΔHsoln is either positive or negative and ΔSsoln is usually negative

An unknown gas contains 83% C and 17% H by mass. If effuses at 0.87 times the rate of CO2 gas under the same conditions. What is the molecular formula of the unknown gas?
A) C2H5
B) C3H3
C) C4H10
D) C7H17

How many liters of SO3(g) are produced at 25°C and 1.00 atm from the combustion of 1.00 kg of coal which is 1.00% S by weight? Assume all the sulfur in the coal ends up as SO3.
A) 0.640 L
B) 5.08 L
C) 7.63 L
D) 11.4 L

How many molecules of N2 are in a 500.0 mL container at 780 mm Hg and 135°C?
A) 8.76 x 1021
B) 9.23 x 1021
C) 2.65 x 1022
D) 2.79 x 1022

A 75.0 L steel tank at 20.0°C contains acetylene gas, C2H2, at a pressure of 1.39 atm. Assuming ideal behavior, how many grams of acetylene are in the tank?
A) 4.33 g
B) 6.01 g
C) 113 g
D) 1650 g

In which case should N2 (g) be more soluble in water?
A) the total pressure is 5 atm and the partial pressure of N2 is 1 atm
B) the total pressure is 3 atm and the partial pressure of N2 is 2 atm
C) the total pressure is 1 atm and the partial pressure of N2 is 0.03 atm
D) the total pressure is 1 atm and the partial pressure of N2 is 0.5 atm

The wavelength of light used to observe an object must be _________ than the object itself.
A) Larger
B) Smaller
C) of higher energy
D) of lower energy

Which covalent bond is the most polar?
A) N-F
B) C-F
C) Cl-F
D) F-F

Which of the following forms a molecular solid?
A) CaO
B) C10H22
C) C(graphite)
D) gold

Which of the following solutions will have the lowest freezing point?
A) 0.010 m Rb I
B) 0.010 m K2SeO4
C) 0.035 m CH3OH
D) 0.015 m SrBr2