Name: _____________________________ period: ___________

Ch. 9 & 13 stoichiometry & gas test [70 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.

Academic Honesty: The answers on this test are my own. I have not discussed the test questions with anyone before or during the test nor have I seen the test questions prior to the exam. If you do not sign or violate any of the preceding items, your semester grade is a F.

Signature: ___________________________

 

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

 

temperature

pressure

Volume

initial

25 °C

?

355 mL

final

325 K

150 kPa

0.45 L

2. A container at STP has 14.0 g CH4, 40. g O2, and 60. g N2. What is the partial pressure of O2 ? [10 points]

3. H2O2 (aq) --> H2O (l) + O2 (g)

How many grams of H2O2 would decompose if there was 5.0 L O2 at 23 °C and 750 torr formed in the above reaction ? [15 points]

 

4. How many grams of methanol (CH3OH) and oxygen (O2) would be needed to form 10.0 grams of water in a reaction involving the combustion of methanol and oxygen ? (15 points)

 

5. What is the % yield in the chemical reaction: 15.0 g N2 + 5.0 g H -->  12.0 g NH3 ? (15 points)