What is the mass in grams of 5.00moles of CH4?

How many moles of oxygen gas O2, are present in a 38g sample of O2

1. 80g

2. 1.188mole

Explanation:

1. We'll begin by obtaining the molar mass of CH4. This is illustrated below:

Molar Mass of CH4 = 12 + (4x1) = 12 + 4 = 16g/mol

Number of mole of CH4 from the question = 5 moles

Mass of CH4 = ?

Mass = number of mole x molar Mass

Mass of CH4 = 5 x 16

Mass of CH4 = 80g

2. Mass of O2 from the question = 38g

Molar Mass of O2 = 16x2 = 32g/mol

Number of mole O2 = ?

Number of mole = Mass / Molar Mass

Number of mole of O2 = 38/32

Number of mole of O2 = 1.188mole