Chapter 5 Ap Chem

A 5.00-L vessel contains 2.00 moles of helium and 3.00 moles of hydrogen at a pressure of 10.0 atm. Maintaining a constant temperature, an additional 3.00 moles of hydrogen are added. What is the partial pressure of hydrogen gas in the vessel at the end? (Assume that the gases behave ideally.) Solve without using a calculator. 6.00 atm 10.0 atm 12.0 atm 20.0 atm

12.0 atm

If all of the chloride in a 3.734-g sample of an unknown metal chloride is precipitated as AgCl with 70.90 mL of 0.2010 M AgNO3, what is the percentage of chloride in the sample? 50.52% 13.53% 1.425% 7.391%

13.53%

A substance contains 23.0 g sodium, 27.0 g aluminum, and 114 g fluorine. How many grams of sodium are there in a 102-g sample of the substance? 4.43 g 23.0 g 14.3 g 102 g

14.3 g

The average atomic mass of rhenium is 186.2. Given that 37.1% of natural rhenium is rhenium-185, what is the other stable isotope?

187/75 Re

The oxidation number of N in Ca(NO3)2 is +2 +3 +4 +5

+5

Diabetics often need injections of insulin to help maintain the proper blood glucose levels in their bodies. How many moles of insulin are needed to make up 45 mL of 0.0062 M insulin solution? 0.00056 mol 7.3 mol 0.14 mol 0.00028 mol

0.00028 mol

Zinc metal is added to hydrochloric acid to generate hydrogen gas, which is collected over a liquid whose vapor pressure is the same as pure water at 20.0°C (18 torr). The volume of the gas mixture is 1.7 L and its total pressure is 0.810 atm. Determine the number of moles of hydrogen gas present in the sample. 42 mol 0.82 mol 1.3 mol 0.056 mol

0.056 mol

Which of the following most closely estimates the density of air at 1.0 atm and 25 degree Celsius to one significant figure? 10 g/L 100 g/L 1 g/L 0.1 g/L

1 g/L

You have a 400-mL container containing 55.0% He and 45.0% Ar by mass at 25°C and 1.5 atm total pressure. You heat the container to 100°C. Calculate the total pressure. 1.88 atm 1.50 atm 2.01 atm 1.20 atm

1.88 atm

You are holding two balloons, an orange balloon and a blue balloon. The orange balloon is filled with neon (Ne) gas and the blue balloon is filled with argon (Ar) gas. The orange balloon has twice the volume of the blue balloon. Which of the following best represents the mass ratio of Ne:Ar in the balloons? 1:1 1:2 2:1 1:3

1:1

For a gas, which two variables are directly proportional to each other (if all other conditions remain constant)? 1. T and n 2. V and n 3. V and T 1 only 2 only 3 only 2 and 3 only

2 and 3 only

A balloon has a volume of 2.32 liters at 24.0°C. The balloon is heated to 48.0°C. Calculate the new volume of the balloon. 2.32 L 2.51 L 2.15 L 4.64 L

2.51 L

What volume is occupied by 21.0 g of methane (CH4) at 27°C and 1.25 atm? 37.2 L 25.8 L 2.32 L

25.8 L

You have 41.6 g of O2 gas in a container with twice the volume as one with CO2 gas. The pressure and temperature of both containers are the same. Calculate the mass of carbon dioxide gas you have in the container. 28.6 g 57.2 g 2.60 g 0.650 g

28.6 g

Aqueous solutions of barium chloride and silver nitrate are mixed to form solid silver chloride and aqueous barium nitrate.The balanced complete ionic equation contains which of the following terms? 2Ba2+(aq) Cl-(aq) 2Ag+(aq) NO3- (aq)

2Ag+(aq)

What volume does 40.5 g of N2 occupy at STP? 32.4 L 64.8 L 50.7 L 1.81 L

32.4 L

You fill a balloon with 2.50 moles of gas at 22°C at a pressure of 1.62 atm. What is the volume of the balloon? 15.7 L 98.0 L 37.4 L 2.79 L

37.4 L

A gaseous mixture containing 1.5 mol Ar and 3.5 mol CO2 has a total pressure of 7.3 atm. What is the partial pressure of CO2? 2.2 atm 1.4 atm 17 atm 5.1 atm

5.1 atm

Zinc metal is added to hydrochloric acid to generate hydrogen gas, which is collected over a liquid whose vapor pressure is the same as pure water at 20.0°C (18 torr). The volume of the gas mixture is 1.7 L and its total pressure is 0.810 atm. Determine the partial pressure of the hydrogen gas in this mixture. 562 torr 580 torr 598 torr 616 torr

598 torr

It is found that 250. mL of a gas at STP has a mass of 0.700 g. What is the molar mass? 62.7 g/mol 2.80 g/mol 15.9 g/mol 11.2 g/mol

62.7

What is the coefficient for oxygen when the following equation is balanced? NH3(g) + O2(g) → NO2(g) + H2O(g) 3 6 7 12

7

A chemical reaction produced 10.1 cm3 of nitrogen gas at 23 °C and 746 mmHg. What is the volume of this gas if the temperature and pressure are changed to 0 °C and 760 mmHg? 9.14 cm3 11.2 cm3 10.8 cm3 9.49 cm3

9.14 cm3

Oxides of copper include CuO and Cu2O. You heat 1.51 g of one of these copper oxides in the absence of air and obtain 1.21 g of Cu.True or false: You must have had CuO instead of Cu2O True False

True

Which conditions of P, T, and n, respectively, are most ideal? low P, high T, low n low P, low T, low n high P, low T, high n high P, high T, high n

low P, high T, low n

Under what conditions does a gasbehave more like a real gas than an ideal gas? low temperature and high pressure high temperature and low pressure high temperature and high pressure low temperature and low pressure

low temperature and high pressure

How many of the following salts are expected to be insoluble in water? sodium sulfide barium nitrate ammonium sulfate potassium phosphate 2 3 none 1

none

The following reactionsZnBr2(aq) + 2AgNO3(aq) ® Zn(NO3)2(aq) + 2AgBr(s)KBr(aq) + AgNO3(aq) ® AgBr(s)+ KNO3(aq)are examples of oxidation-reduction reactions acid-base reactions precipitation reactions Two of these

precipitation reactions

A gas is found to diffuse at half the rate of methane (CH4). Which of the following could be this gas? SO2 N2 CO2 O2

SO2

Of the following real gases, which would be expected to have the lowest van der Waals correction for intermolecular attractions? O2 NH3 H2 Cl2

H2

All of the following are in aqueous solution. Which is incorrectly named? HC2H3O2, acetic acid HBr, bromic acid H2SO3, sulfurous acid HNO2, nitrous acid HClO3, chloric acid

HBr, Bromic Acid

Which of the following is a strong acid? HF KOH HClO4 HBrO2

HClO4

Four identical 1.0-L flasks contain the gases He, Cl2, CH4, and NH3, each at 0°C and 1 atm pressure. For which gas do the molecules have the highest average velocity? NH3 all gases the same He Cl2

He

An unknown substance dissolves readily in water but not in benzene (a nonpolar solvent). Molecules of what type are present in the substance? nonpolar neither polar nor nonpolar either polar or nonpolar polar

Polar

Which of the following is included as a postulate in the kinetic molecular theory of an ideal gas? In an average collision between molecules, both molecules have the same kinetic energy. All collisions between molecules are elastic. The distance between gas molecules is small compared with the size of the molecule. All molecules move randomly in zigzag directions.

All collisions between molecules are elastic.

If the Thomson model of the atom had been correct, Rutherford would have observed: Alpha particles going through the foil with little or no deflection. Alpha particles bouncing off the foil. None of the above observations is consistent with the Thomson model of the atom. Positive particles formed in the foil. Alpha particles greatly deflected by the metal foil.

Alpha particles going through the foil with little or no deflection.

Which of the following would have a higher rate of effusion than C2H2? Cl2 CH4 O2 N2

CH4

For which gas are the molecules diatomic? He Cl2 CH4 NH3

Cl2

Real gases are those that deviate from ideal behavior are only available naturally in the earth's atmosphere are called real gases because their behavior can easily be modeled only behave ideally at high pressures or low temperatures

deviate from ideal behavior