CaOsCO2gCaCO3s Express your answer using two significant fig

CaO(s)+CO2(g)CaCO3(s)

Express your answer using two significant figures.

For each reaction, calculate the mass (in grams) of the product formed when 2.9 g of the underlined reactant completely reacts. Assume that there is more than enough of the other reactant.

Ba(s)+Cl2(g)BaCl2(s)

Express your answer using two significant figures.

2Mg(s)+O2(g)2MgO(s)

Express your answer using two significant figures.

4Al(s)+3O2(g)2Al2O3(s)

Express your answer using two significant figures.

Solution

CaO + CO2 = CaCO3

2.9 g of CaO = 2.9 / 56 = 0.05 moles

So 0.05 moles of CaCO3 is formed

Mass = 0.05 x 100.0869

= 5.1 grams

Ba + Cl2 = BaCl2

2.9 g of Ba = 2.9 / 137.327 = 0.02 mol

The number of moles of BaCl2 formed = 0.02 mol

Mass of BaCl2 = 0.02 x 208.233

= 4.4 g

2Mg + O2 = 2 MgO

2.9 g of Mg = 2.9 / 24.305 = 0.119 mol

Number of mol of MgO formed = 0.119 mol

Mass of MgO = 0.119 x 40.3

= 4.8 grams

4Al + 3O2 = 2Al2O3

2.9 g of Al = 2.9 / 26.98 = 0.107 mol

Number of mol of Al2O3 formed = 0.054 mol

Mass of Al2O3 formed = 0.054 x 101.96

= 5.5 grams