Question

What is the mass in grams of `1.88 xx10^24` molecules `"CH"_2"O"`?

Answer 1

93.7 g

Explanation:

I am going to assume that there are `1.88 * 10^24` molecules of `"CH"_2"O"`

In this case, the go-to formula is

`"moles" = "molecules"/"Avogadro's number"`

`"moles" = 1.88 xx 10^24 color(red)(cancel(color(black)("molecules"))) xx "1 mol"/(6.022 xx 10^23 color(red)(cancel(color(black)("molecules")))) = "3.122 mol"`

Relative molecular mass is obtained from the P. Table

`12.0107 + (2xx1.00794) + 15.9994 = 30.02598`

`"mass" = 3.122 color(red)(cancel(color(black)("mol"))) xx "30.02598 g"/(1 color(red)(cancel(color(black)("mol")))) = "93.7 g"`

Answer: `"93.7 g"`