A sample contains 75 g NaCl with a molar mass of 58 g/mol. How many moles are present?

Study for the MTLE Recalls Test with detailed quizzes and thorough explanations. Prepare to excel with multiple choice questions and comprehensive reviews!

Multiple Choice

A sample contains 75 g NaCl with a molar mass of 58 g/mol. How many moles are present?

Explanation:
To find how many moles are present, divide the mass by the molar mass. The molar mass of NaCl is 58 g/mol, so moles = 75 g ÷ 58 g/mol ≈ 1.293 mol. With two significant figures, that becomes about 1.3 moles. So the sample contains roughly 1.3 moles. For perspective, 1.0 mol would correspond to 58 g, 0.75 mol to 43.5 g, and 2.0 mol to 116 g, which don’t match the given mass.

To find how many moles are present, divide the mass by the molar mass. The molar mass of NaCl is 58 g/mol, so moles = 75 g ÷ 58 g/mol ≈ 1.293 mol. With two significant figures, that becomes about 1.3 moles. So the sample contains roughly 1.3 moles. For perspective, 1.0 mol would correspond to 58 g, 0.75 mol to 43.5 g, and 2.0 mol to 116 g, which don’t match the given mass.

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy