Question

Write the balanced equation, then outline the steps necessary to determine the information requested in each of the following reactions. (Omit states-of-matter from your answer. Use the lowest possible whole number coefficients.) (a) The number of moles and the mass (in g) of Mg required to react with 5.00 g of HI and produce MgI2 and H2.(b) The number of moles and the mass (in g) of oxygen formed by the decomposition of 1.257 g of silver(I) oxide.(c) The number of moles and the mass (in g) of calcium carbonate, CaCO3, required to produce 277 g of carbon dioxide. (CaO is the other product.)(d) The number of moles and the mass (in g) of water formed by the combustion of 22.0 kg of acetylene, C2H2, in an excess of oxygen.(e) The number of moles and the mass (in g) of calcium peroxide, CaO2, needed to produce 2.130 kg of calcium oxide, CaO. (O2 is the other product.)

Answer 1

a) Mg + 2HI ---> MgI2 + H2

No of mol of HI = 5/128 = 0.039 mol

No of mol of Mg needed = 0.039 mol

mass of Mg needed = 0.039*24 = 0.936 g

b)   2Ag2O ---> 4Ag + O2

nO of mol of AgO = 1.257/123.86 = 0.01 mol

no of mol of o2 formed = 0.01 mol

mass of O2 formed = 0.01*32 = 0.32 g

c) CaCO3 ---> CaO + CO2

NO Of mol of CO2 formed = 277/44 = 6.3 mol

NO OF mol of CaCo3 = 6.3 mol

mass of CaCo3 required = 6.3*100 = 630 g

d) 2C2H2 + 5O2 ---> 4CO2 + 2H2O

NO OF mol of C2H2 = 22.0*10^3/26 = 846.15 mol

no of mol of water formed = 846.15 mol

mass of water formed = 846.15*18 = 15230.7 g

e) 2CaO2 ---> 2CaO + O2

no of mole of CaO produced = 2.13*10^3/56 = 38 mol

no of mol of CaO2 required = 38 mol

mass of CaO2 required = 38*72 = 2736 g