Question

For each of the following unbalanced reactions, suppose exactly 1.00 g of each reactant is taken. Indicate which reactant is the limiting reagent. Calculate the mass of each product that is expected.

1.UO₂(s) + HF(aq) → UF₄(aq) + H₂O(l)

2.NaNO₃(aq) + H₂SO₄(aq) → Na₂SO₄(aq) + HNO₃(aq)

3.Zn(s) + HCl(aq) → ZnCl₂(aq) + H₂(g)

4.B(OH)₃(s) + CH₃OH(l) → B(OCH₃)₃(s) + H₂O(l)

Answer 1

1.UO2(s) + 4HF(aq) → UF4(aq) + 2H2O(l)

No of mol of UO2 = 1/270.03   = 0.0037 mol

No of mol of HF = 1/20.01 = 0.05 mol

limiting reactant is UO2

mass of UF4 produced = 0.0037*314.02 = 1.16 grams

mass of H2O = 0.0037*2*18 = 0.1332 grams

2. 2NaNO3(aq) + H2SO4(aq) → Na2SO4(aq) + 2HNO3(aq)

No of mol of NaNO3 = 1/84.9947 = 0.0117 mol

No of mol of H2SO4 = 1/98 = 0.01 mol

limiting reactant is   NaNo3

mass of Na2SO4 = 0.0117/2 *142.04 = 0.831 grams

massof HNO3 = 0.0117*63.01 = 0.74 grams