100ml of calcium hydroxide ca(oh)2 , a liter of it contains 30 g , reacted with 50 ml of hydrochloric acid (hcl) what is the molarity of acid solution? 1-4.05 2-1.61 3-0.40 4-0.81

2 — 1.6 mol·L⁻¹

Explanation:

1. Write the chemical equation for the reaction.

Ca(OH)₂ + 2HCl ⟶ CaCl₂ + 2H₂O

2. Calculate the mass of Ca(OH)₂.

V = 100 mL

1000 mL of solution contain 30 g Ca(OH)₂     Calculate the mass of Ca(OH)₂

Mass of Ca(OH)₂ = 100 × 30/1000

Mass of Ca(OH)₂ = 3.00 g Ca(OH)₂

3. Calculate the moles of Ca(OH)₂

1 mol Ca(OH)₂ = 74.09 g     Calculate the moles of Ca(OH)₂

Moles of Ca(OH)₂ = 3.00 × 1/74.09

Moles of Ca(OH)₂ = 0.0405 mol Ca(OH)₂

4. Calculate the moles of HCl

2 mol HCl ≡ 1 mol Ca(OH)₂     Calculate the moles of HCl

Moles of HCl = 0.0405 × 2/1

Moles of HCl = 0.0810 mol HCl

5. Calculate the molar concentration of the HCl

c = n/V

V = 50 mL = 0.050 L   Calculate the concentration

c = 0.0810/0.050

c = 1.6 mol·L⁻¹

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