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

The answer is 64 grams, or:

D. 64

Answer 2

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

Step-by-step 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.

`(32 \ g \ CH_3OH)/(1 \ mol \ CH_3OH)`

Multiply by the given number of moles, which is 2.0

`2.0 \ mol \ CH_3OH *(32 \ g \ CH_3OH)/(1 \ mol \ CH_3OH)`

The moles of methanol will cancel each other out.

`2.0 \ *(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.