Euler gas Stoichiometry Act 1

(For #1-3) Mr Wangxian installed a pneumatic piston near his door that is triggered to lock the door in case of an attack and placed 13.0 grams of NaN3 in the empty piston. It is powered by the reaction below:How many moles of NaN3 was available for the reaction? (Molar mass of NaN3 is 65 g/mol)

• A. 0.2 mol

• B. 0.3 mol

• C. 0.1 mol

• D. 0.4 mol

Assuming that all of the NaN3 reacted, how many moles of nitrogen gas was formed?

• A. 0.2 mol

• B. 0.3 mol

• C. 0.1 mol

• D. 0.4 mol

Assuming that all of the NaN3 reacted and the volume occupied by the solid sodium is negligible, what is the final volume of the piston?

• A. 6.27 L

• B. 7.26 L

• C. 6.72 L

• D. 2.76 L

22.4 L of compound A was measured at STP after a gaseous reaction, how many moles of A was in the sample?

• A. 0.1 mol

• B. 0.01 mol

• C. 10 mol

• D. 1.0 mol

(For #5-7) Acetylene (C2H2) is formed by the reaction of water with calcium carbide, according to the following equation:

Mr Xiyao was told to prepare 10 L (at STP) of acetylene in the laboratory. How many moles of acetylene should Ms Xiyao produce?

• A. 0.644 mol

• B. 0.446 mol

• C. 0.464 mol

• D. 4.064 mol

How many moles of CaC2 is needed to produce 10 L of acetylene?

• A. 0.644 mol

• B. 0.446 mol

• C. 0.464 mol

• D. 4.064 mol

How many grams of CaC2 must Ms Xiyao prepare? (Molar mass of CaC2 is 64 g/mol)

• A. 68.2 g

• B. 62.8 g

• C. 28.6 g

• D. 26.8 g

(For #8-10) Mr Sang Cheng burned 50 L of acetylene (C2H2) at STP in a constant pressure piston. The piston expanded until the reaction was over. The reaction proceeds:

How many moles of acetylene is available for reaction?

• A. 2.23 mol

• B. 3.22 mol

• C. 3.23 mol

• D. 3.32 mol

Assuming that all of the acetylene reacted, how many moles of CO2 was formed?

• A. 6.64 mol

• B. 6.46 mol

• C. 6.44 mol

• D. 4.46 mol

What volume is occupied by the CO2 at STP?

• A. 0.10 L

• B. 1.00 L

• C. 10.0 L

• D. 100 L