Question

For the following reactions: 1) Name the reactants and products, 2) balance the equation, and 3) ... Edit question For the following reactions: 1) Name the reactants and products, 2) balance the equation, and 3) calculate the molecular mass of the reactants and products. Starting with 2.0 grams of each reactant, 4) identify the limiting reagent and 5) determine the mass of the first product.

____Ca (s) + _____H2O (l) → _____Ca(OH) 2 (aq) + ____H2 (g)

Answer 1

Balanced equation:
Ca(s) + 2 H₂O(l) = Ca(OH)₂(aq) + H₂(g)

Calcium + water = calcium hydroxide + hydrogen
Reaction type: single replacement

Molecular mass of Calcium Ca = 40 g/mol

Molecular mass of water H2O = (2*1 + 16*1) = 18 g/mol

Molecular mass of Calcium Hydroxide Ca(OH)2

= 40 + 2*(16+1) = 74 g/mol

Molecular mass of Hydrogen H2 = 2*1 = 2 g/mol

40 g Ca reacts with = 2*18 = 36 g H2O

2 g of Ca react with = 36*2/40 = 1.8 g H2O

If all 2 g Ca consumed, only 1.8 g H2O required to complete the reaction

Calcium (Ca) is limiting reagent

H2O is excess reagent

40 g Ca required to form = 74 g Ca(OH)2

2 g Ca required to form = 74*2/40 = 3.7 g Ca(OH)2

40 g Ca required to form = 2 g H2

2 g Ca required to form = 2*2/40 = 0.1 g H2