Question

How many MOLES of boron tribromide are present in 3.20 grams of this compound ?

_______ moles.
2. How many GRAMS of boron tribromide are present in 3.63 moles of this compound ?
______ grams.

Answer 1

1) There are 0.0128 moles of BBr3 present in 3.20 grams of this compound

2) There are 909.35 grams of BBr3 present in 3.63 moles of this compound

Step-by-step explanation:

Step 1: Given data

Boron tribromide = BBr3

Molar mass of Boron = 10.81 g/mole

Molar mass of Bromide = 79.9 g/mole

Molar mass of Boron tribromide = 10.81 + 3*79.9 = 250.51 g/mole

Step 2: Calculating number of moles

Number of moles = mass / molar mass

Number of moles of BBr3 = 3.20 grams / 250.51 g/mole

Number of moles of BBr3 = 0.0128 moles

Step 3: Calculating mass

If we have 3.63 moles of boron tribromide (= BBr3)

Mass of BBr3 = number of moles of BBr3 * Molar mass of BBr3

Mass of BBr3 = 3.63 moles * 250.51 g/mole

Mass of BBr3 = 909.35 grams