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Question
If 0.2 mol of the following substance is required how many grams of that substance should be taken?
Sodium chloride
Solution
We know that,
Number of moles of a substance = `"Mass of the substance in grams"/"Molecular mass of the substance"`
Molar mass = sum of constituent atomic masses
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Number of moles of a substance = `"Mass of the substance in grams"/"Molecular mass of the substance"`
Let Mass of the substance in grams be x,
`0.2 = "x"/58.5 = 11.7` g
We need, 11.7 g of NaCl for obtaining 0.2 moles of NaCl.
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