1. One A molecule must collide with one B molecule to produce one molecule of C.



2. Ten collisions between an A molecule and a B molecule are required to produce ten molecule of C. Thus, 10 molecules of A and 10 molecules of B are needed to prepare 10 molecules of C. Test this hypothesis by allowing 10 molecules of A to react with 10 molecules of B.



3. Ten molecules of A and ten molecules of B are needed to prepare ten molecules of C. The mass of one molecule of A is 2.2973 • 10^-23 g and the mass of one molecule of B is 4.6585 • 10^-23 g. The grams of A and B needed to prepare 10 molecules of C are
   


4. Although 5 A molecules were added to the reaction mixture in Problem #3 (10 molecules of A and 10 molecules of B) and thus 15 molecules of A were allowed to react with 10 molecules of B, there was no increase in the number of C molecules produced. Since there are only 10 B molecules, then only 10 pairs of A and B molecules can combine to form C molecules and hence the maximum number of C molecules that can be formed is 10.



5. Since the mass of 10 molecules of C is 6.9558 • 10^-22 g , then the mass of one molecule of C is 6.9558 • 10^-23 g . The mass of Avogadro's number of C molecules , i.e. the molar mass of C, is
   


6. The number of molecules of A in 2.2973 • 10^-22 g of A is 10 and the number of B molecules in 6.9878 • 10^-22 g of B is 15.
   
   When 10 molecules of A were allowed to react with 15 molecules of B, 10 molecules of C formed. Also, 5 molecules of unreacted B were left in the container. At the end of the reaction a total of 15 molecules (5 B molecules + 10 C molecules) were present in the container.



7. A     +     B           C