Question

1) Calculate the molarity of a solution produced by dissolving 35.7 g of solid Cu(ClO3)2 in enough water to make 250 mL of solution.
2) How many moles of SnCO3 are in 317.4 mL of a 0.75M solution?

Answer 1

Answer:

1. 0.62M

2. 0.24mol

Explanation:

Molarity (M) = number of moles (n) ÷ volume (V)

1.) According to this question, 35.7 g of solid Cu(ClO3)2 was dissolved in water to make 250mL solution.

Molar mass of Cu(ClO3)2 where Cu = 63.5, Cl = 35.5, O = 16 is;

63.5 + {35.5 + 16(3)}2

63.5 + {35.5 + 48}2

63.5 + {83.5}2

63.5 + 167

= 230.5g/mol

Using mole = mass/molar mass

mole = 35.7/230.5

= 0.1548

= 0.155mol

Volume = 250mL = 250/1000 = 0.250L

Molarity = number of moles ÷ volume

Molarity = 0.155 ÷ 0.250

Molarity = 0.62M

2.) Molarity = number of moles ÷ volume

number of moles = Molarity × volume

Volume of SnCO3 solution = 317.4 mL = 317.4/1000 = 0.3174 L

number of moles (n) = 0.75M × 0.3174 L

n = 0.238

n = 0.24mol