Ch. 13, 15 gas & solution **test ** [80 points] Honors Chemistry

Show your work in an organized manner, includes any relevant equation / formula, proper units in your work / answer, and the proper number of significant figures in your answer.

1. solve for the unknown pressure. [15 points]

Initial

Final

pressure

500. torr

?

volume

750. mL

2.0 L

temperature

20. °C

400. K

2. A container at STP has 4.0 g H_{2}, 40. g O_{2}, and 60. g N_{2}. What is the partial pressure of O_{2} ? [10 points]

3. H_{2}O_{2 (aq)} --> H_{2}O_{ (l)} + O _{ 2 (g)}

How many grams of H_{2}O_{2} would decompose if there was 5.0 L O_{2} at 25 °C and 1.0 atm formed in the above reaction ? [15 points]

4. Na_{2}CO_{3 (aq)} + FeCl_{3 (aq)} --> ___ grams of a precipitate. [15 points]

100. mL 50. mL

200. mM 300. mM

5. Describe how to prepare 275 mL of 10.0 mM glucose using 25 mM glucose, C_{6}H_{12}O_{6}. [10 points]

6. 1.0 g nonelectrolyte dissolved in 10.0 benzene (C_{6}H_{6}) has a boiling point of 83.0 °C. What is the molar mass of the nonelectrolyte ? [the boiling point of benzene is 80.1 °C and its K_{b} is 2.5 °C / molal; 15 points]