Answer:
a)1.56 M
b) 0.376 M
c) 0.599 M
Explanation:
Step 1: Molarity
Molarity = Number of moles / volume in L
Number of moles = mass / Molar mass
(a) 7.49 g of methanol (CH3OH) in 1.50 * 10² mL of solution
Volume = 1.50 * 10² mL = 0.15 L
Molar mass of CH3OH = 32.04 g/mol
Number of moles CH3OH = 7.49 grams / 32.04 g/mol
Moles of CH3OH = 0.234 moles
Molarity CH3OH = 0.234 moles / 0.15 L
Molarity CH3OH = 1.56 M
(b) 9.18 g of calcium chloride (CaCl2) in 2.20 × 10² mL of solution:
Volume = 2.20 × 10² mL = 0.22L
Molar mass of CaCl2 = 110.98 g/mol
Number of moles CaCl2 = 9.18 grams /110.98 g/mol
Moles CaCl2 = 0.0827 moles
Molarity CaCl2 = 0.0827 moles / 0.22L
Molarity CaCl2 = 0.376 M
(c) 6.51 g of naphthalene (C10H8) in 85.2 mL of benzene solution:
Volume = 85.2 mL = 0.0852L
Molar mass of C10H8 = 128.17 g/mol
Number of moles C10H8 = 6.51 grams / 128.17 g/mol
Moles C10H8 = 0.051 moles
Molarity C10H8 = 0.051 moles / 0.0852 L
Molarity C10H8 = 0.599 M
