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 H2, 40. g O2, and 60. g N2. What is the partial pressure of O2 ? [10 points]

3. H2O2 (aq) --> H2O (l) + O 2 (g)

How many grams of H2O2 would decompose if there was 5.0 L O2 at 25 °C and 1.0 atm formed in the above reaction ? [15 points]

 

4. Na2CO3 (aq) + FeCl3 (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, C6H12O6. [10 points]

6. 1.0 g nonelectrolyte dissolved in 10.0 benzene (C6H6) 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 Kb is 2.5 °C / molal; 15 points]