Question

Find the number of moles in 3.70 x 10^-1 g of boron.

1) What is the molar mass of boron to three significant figures?

2) What is the conversion factor you will use to convert grams of boron to moles of boron?

3) Use the conversion factor to calculate the number of moles in 3.70 x 10^-1 g of boron.

Answer 1

Molar mass of boron= 10.8 gmol-1

The conversion factor to convert mass of boron to moles of boron is the molar mass of boron

0.034 moles of boron

Step-by-step explanation:

Molar mass of boron= 10.8 gmol-1

We know that;

Number of moles= mass/molar mass

We already know the molar mass of boron as 10.8 gmol-1. The given mass of boron according to the question is 3.70 x 10^-1 g.

From our formula;

Number of moles= 3.70 x 10^-1 g/ 10.8gmol-1

Number of moles= 0.034 moles of boron