More Stoichiometric Gram to Gram Calculations  
1. Although mercury is a metal at room temperature it is a liquid, and it has a density of 13.6 g/mL. How many kilograms of mercuric sulphide, HgS, theoretically are needed to prepare one 'commercial flask'. This standard unit contains 2.55 L of mercury. The reaction used to prepare this sample is as follows.

                     4 HgS + 4 CaO -------> 4 Hg + 3 CaS + CaSO4
2. How many grams of nitric acid, HNO3, are needed to react with 2.56 moles of Cu in the following reaction?

                      3 Cu + 8 HNO3 ----------> 3 Cu(NO3)2 + 2 NO + 2 H2O
3. Given that: XeF6(l) + 3 H2O(l) ---------> XeO3(s) + 6 HF(g)

How many grams of water are needed to produce 59.8 grams of XeO3?
4. How many grams of CO2 gas are released when a 50.0 grams sample of Na2CO3 that is 60.0 percent pure reacts completely with excess HCl?

          Na2CO3(aq) + 2 HCl(aq) -----------> CO2(g) + H2O(l) + 2 NaCl(aq)
5. What mass of iron is required to convert 235.8 kg of PbS into Pb? The reaction is:

          PbS(s) + Fe(s) ------> Pb(s) + FeS(s)
6. When MoO3 and Zn are heated together they react

           3 Zn(s) + 2 MoO3(s) -------> Mo2O3(s) + 3 ZnO(s)

What mass of ZnO is formed when 20.0 grams of MoO3 is reacted with Zn?
7.  What weight of hydrogen gas is needed to react with 10.00 grams of each of the following compounds: AgCl, Ag2Se and Ag3PO4? The reaction with each compound produces silver metal plus an acid: HCl, H2Se and H3PO4
8. The exothermic gas forming reaction:

        (CH3)2NNH2(s) + 2 N2O4(l) -------> 2 CO(g) + 3 N2(g) + 4 H2O(g)

Is the source of energy in some space vehicle operations. What weight of dinitrogen tetroxide is needed to react with 10.00 kg of dimethylhydrazine? 
9. Calculate the mass, in kilograms, of oxygen that can be obtained by treating 117 kg of solid sodium peroxide, Na2O2, with water according to the following reaction.

         2 Na2O2 + 2 H2O ------> 4 NaOH + O2
10. Calculate the number of grams of mercuric oxide, HgO, needed to produce 8 grams of oxygen.

          2 HgO -----> 2 Hg + O2
11.  Calcium chloride, CaCl2, is formed as shown by the following equation:

            Ca(OH)2 + 2 HCl ------> CaCl2 + 2 H2O

How many grams of calcium chloride are formed by the complete reaction of 37 grams of calcium hydroxide, Ca(OH)2?
           Answers