1) how many atoms are in a 12.0 g sample of carbon?
a. 1.74 * 10^23 atoms
b. 6.02 * 10^23 atoms
c. 1.04 * 10^24 atoms
d. 7.24 * 10^24 atoms

2) given the following chemical equation:
ag no3 (aq) + kl (aq) agl(s) + kno3 (aq)
how many grams of potassium iodide will produce 750 grams of silver iodide, when there is an excess of silver nitrate?
a. 235
b. 707g
c. 529.79 g
d. 301 g

3) what is the molecular formula of a compound that has an empirical formula of c2h5 and a molecular mass of 116 grams/mole?
a. c2h5
b. c4h10
c. c6h15
d. c8h20

4) boron reacts with oxygen gas to form boron oxide, as shown in the reaction below:
4b(s) + 3o2(g) > 2b2o3(s)
how many grams of boron are needed to completely react with 492 g of oxygen gas?
a. 225.5g
b. 102 g
c. 216 g
d. 432 g

5) sulfuric acid is used in large quantities in petroleum refining and metallurgy as well as in the manufacture of fertilizer. if an industrial process requires 4.90 grams of h2so4, how many molecules are in this amount?
a. 7.00 * 10^20
b. 3.18 * 10^23
c. 6.02 * 10^23
d. 2.11 * 10^23

6) what is the mass of five mole of helium gas?
a. 2 g
b. 4 g
c. 8 g
d. 20 g