Simple Stoichiometry Practice Quiz

Hi Students,  You may use paper, pencil, calculator, and Periodic Table to answer the following questions. This is just for practice.  Try to simulate a real test situation. It will help you when it is the real thing. Try to work as quickly as you can without being sloppy. Time yourself, and the last question will ask you to type in the time you spent.Click on SUBMIT when you are ready. You will get an immediate correct/incorrect response for each question. If you want to clear your responses, click on RESET. 

 

Please type in your name:

1. What is the  molar mass of   Al2(SO4)3   ?                         

a) 262.3 g/mole

b) 342.3 g/mole

c) 278.1 g/mole

d) none of these

2. What is the mass of 0.243 moles of MgO?

a) 9.79 g

b) 166g

c) 27.8 g

d) none of these

3. How many moles of molecules are contained in 73.0 g CO?

a) 2,040 moles

b) 0.384 moles

c) 2.61 moles

d) none of these

4. How many molecules are contained in 16.0 g of NO gas?

a) 3.21 x 10^23 molecules

b) 9.63 x 10^24 molecules

c) 1.81 x 10^25 molecules

d) none of these

5. The empirical formula of a compound is CH. Its molar mass has been experimentally determined to be 78.0 g/mole. What is its molecular formula?

a) CH

b) C6H6         

c)  C2H6              

d) none of these

6. Calculate the % oxygen in chlorous acid,  HClO2 .

a) 46.7%

b) 23.4%

c) 30.5%

d) none of these

7. After balancing this equation, P4S3(s) + O2(g) à P4O10(s) + SO2(g) , the coefficients (in the order the substances are listed) are

a) 1,5,1,3

b) 2,10,2,3

c) 1,8,1,3

d) none of these

8. Consider the reaction  2P(s) + 3Cl2(g) à 2PCl3(l) . When 0.752 mole P reacts, how many moles of the chlorine gas react?

a) 0.501 mole

b) 35.0 moles

c) 1.13 moles

d) none of these

For questions 9 & 10, refer to this reaction   6Li(s) + N2(g) à 2Li3N(s)

9. When 15.0 g of Li react with excess nitrogen gas, how many moles of the lithium nitride can be made?                                                

a) 5.00 moles

b)25.2 moles

c) 0.720 mole

d) none of these

10. When 3.72 moles Li and 0.851 mole nitrogen gas react, how many moles of lithium nitride can be made?

a)  1.70 moles

b) 23.2 moles

c) 1.24 moles

d) none of these                   

11. How much time did you spend on this practice quiz?