Question

A chemist has 2.0 mol of methanol (CH3OH). The molar mass of methanol is 32.0 g/mol. What is the mass, in grams, of the sample? 16 30 32 64

Answer 1

Answer:

$\boxed {\boxed {\sf D. \ 64 \ grams }}$

Explanation:

Given the moles, we are asked to find the mass of a sample.

We know that the molar mass of methanol is 32.0 grams per mole. We can use this number as a fraction or ratio.

$\frac{32 \ g \ CH_3OH}{1 \ mol \ CH_3OH}$

Multiply by the given number of moles, which is 2.0

$2.0 \ mol \ CH_3OH *\frac{32 \ g \ CH_3OH}{1 \ mol \ CH_3OH}$

The moles of methanol will cancel each other out.

$2.0 \ *\frac{32 \ g \ CH_3OH}{1 }$

The denominator of 1 can be ignored.

$2.0 * 32 \ g\ CH_3OH$

Multiply.

$64 \ g \ CH_3OH$

There are 64 grams of methanol in the sample.