Gen CHM, ch. 6+8 Practice Problems

12.011 g mol

26.038 g mol

185.846 g mol

98.079 g mol

the percent composition of ammonia, NH3

82.24%

the percent composition of photographic fixer solution (“hypo”), Na2S2O3

30.36%

the percent of calcium ion in Ca3(PO4)2

38.76%

Determine the percent ammonia, NH3, in Co(NH3)6Cl3, to three significant figures.

38.2%

Determine the percent water in CuSO4•5H2O to three significant figures

36.1%

Determine the Empircal Formula. 15.8% carbon and 84.2% sulfur

CH2O.

Dichloroethane, a compound that is often used for dry cleaning, contains carbon, hydrogen, and chlorine. It has a molar mass of 99 g/mol. Analysis of a sample shows that it contains 24.3% carbon and 4.1% hydrogen. What is its molecular formula?

C2H4Cl2

Determine the empirical and molecular formula for chrysotile asbestos. Chrysotile has the

following percent composition: 28.03% Mg, 21.60% Si, 1.16% H, and 49.21% O. The molar

mass for chrysotile is 520.8 g/mol

Mg6Si4H6O16

A major textile dye manufacturer developed a new yellow dye. The dye has a percent composition of 75.95% C, 17.72% N, and 6.33% H by mass with a molar mass of about 240 g/mol. Determine the molecular formula of the dye

C15H15N3

Determine the molarity. 0.444 mol of CoCl2 in 0.654 L of solution

0.679 M

Determine the molarity. 98.0 g of phosphoric acid, H3PO4, in 1.00 L of solution

1.00 M

Determine the molarity. 0.2074 g of calcium hydroxide, Ca(OH)2, in 40.00 mL of solution

0.06998 M

Determine the molarity. 10.5 kg of Na2SO4•10H2O in 18.60 L of solution

1.75 M

Determine the molarity. 7.0 × 10–3 mol of I2 in 100.0 mL of solution

0.079 M

Determine the molarity. 1.8 × 104 mg of HCl in 0.075 L of solution

6.6 M

What is the mass of solute in 200.0 L of a 1.556-M solution of KBr?

3.703 × 104 g

What is the molarity of KMnO4 in a solution of 0.0908 g of KMnO4

in 0.500 L of solution?

158.0264 g/mol

Calculate the number of moles and the mass of the solute in the solution. 2.00 L of 18.5 M H2SO4, concentrated sulfuric acid

3.63 × 10³ g H2SO4

Calculate the number of moles and the mass of the solute in the solution. 100.0 mL of 3.8 × 10–6 M NaCN

3.8 × 10^-5 g NaCN

Calculate the number of moles and the mass of the solute in the solution. 5.50 L of 13.3 M H2CO

5.9 * 10^-7 mol FeSO4

Calculate the number of moles and the mass of the solute in the solution. 325 mL of 1.8 × 10–6M FeSO4

8.9 * 10^-5 g FeSO4

What is the molarity of KMnO4 in a solution of 0.0908 g of KMnO4

in 0.500 L of solution?

1.15 × 10^-3 M

Calculate the molarity. 0.195 g of cholesterol, C27H46O, in 0.100 L

5.04 × 10^-3 M

Calculate the molarity. 4.25 g of NH3 in 0.500 L of solution

0.499 M

Calculate the molarity. 1.49 kg of isopropyl alcohol, C3H7OH, in 2.50 L

9.92 M

If 4.12 L of a 0.850 M-H3PO4 solution is be diluted to a volume of 10.00 L, what is the concentration the resulting solution?

0.350 M

What volume of a 0.33-M C12H22O11 solution can be diluted to prepare 25 mL of a solution

with a concentration of 0.025 M?

1.9mL

What is the molarity of the diluted solution when the following solution is diluted.
1.00 L of a 0.250-M solution of Fe(NO3)3is diluted to a final volume of 2.00 L

0.125 M

What is the molarity of the diluted solution when the following solution is diluted.
0.5000 L of a 0.1222-M solution of C3H7OH is diluted to a final volume of 1.250 L

0.04888 M

What is the molarity of the diluted solution when the following solution is diluted.
2.35 L of a 0.350-M solution of H3PO4 is diluted to a final volume of 4.00 L

0.206 M

What is the molarity of the diluted solution when the following solution is diluted.
22.50 mL of a 0.025-M solution of C12H22O11 is diluted to 100.0 mL

0.0056 M

An experiment in a general chemistry laboratory calls for a 2.00-M solution of HCl. How many mL of 11.9 M HCl would be required to make 250 mL of 2.00 M HCl?

42.0 mL

A typical barometric pressure in Redding, California, is about 750 mm Hg. Calculate this pressure in atm and kPa.

0.987 atm
100 kPa

A typical barometric pressure in Kansas City is 740 torr. What is this pressure in atmospheres,in millimeters of mercury, and in kilopascals?

740 mmHg
98.6 kPa

A spray can is used until it is empty except for the propellant gas, which has a pressure of 1344 torr at 23 C. If the can is thrown into a fire (T = 475 C), what will be the pressure in the hot can?

3.40 * 10³ torr

A 2.50-L volume of hydrogen measured at –196 C is warmed to 100 C. Calculate the

volume of the gas at the higher temperature, assuming no change in pressure.

12.1 L

A weather balloon contains 8.80 moles of helium at a pressure of 0.992 atm and a

temperature of 25 C at ground level. What is the volume of the balloon under these conditions?

217 L

How many moles of gaseous boron trifluoride, BF3, are contained in a 4.3410-L bulb at

788.0 K if the pressure is 1.220 atm? How many grams of BF3?

5.553 g

Iodine, I2, is a solid at room temperature but sublimes (converts from a solid into a gas) when warmed. What is the temperature in a 73.3-mL bulb that contains 0.292 g of I2 vapor at a pressure of 0.462 atm?

359 K

A cylinder of O2(g) used in breathing by patients with emphysema has a volume of 3.00 L at a pressure of 10.0 atm. If the temperature of the cylinder is 28.0 °C, what mass of oxygen is in the cylinder?

38.8 g