How many grams of NaOH are needed to make 100 mL of a 0.5 M solution of NaOH ? (Atomic weight: Na = 23 , O = 16 , H = 1 ) - Chemistry MCQ WBCS Prelims 2026 | ExamTest.live

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How many grams of NaOH are needed to make 100 mL of a 0.5 M solution of NaOH ? (Atomic weight: Na = 23, O = 16, H = 1)

Solution & Step-by-step Explanation

Let's calculate step-by-step: 1. Find the molar mass of NaOH : Molar Mass = 23 + 16 + 1 = 40 g/mol 2. Use the molarity formula: Molarity (M) = \frac{Weight of solute ( W )}{Molar mass} \times \frac{1000}{Volume of solution in mL ( V )} 3. Substitute the values: 0.5 = \frac{W}{40} \times \frac{1000}{100} 0.5 = \frac{W}{40} \times 10 0.5 = \frac{W}{4} W = 0.5 \times 4 = 2 g

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How many grams of NaOH are needed to make 100 mL of a 0.5 M solution of NaOH ? (Atomic weight: Na = 23, O = 16, H = 1)

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