Question

how many moles of hydrogen gas in 90grames

Answer 1

So the molar mass of a Hydrogen molecule is 2. If you have 10 grams of Hydrogen molecules, you have 5 moles of Hydrogen molecules (10 moles of Hydrogen atoms). Avogadro's number is 6.0225x10^23. This means that one mole of a substance has that many particles.

so 90g=45mole of hydrogen gas

Answer 2

Number of moles=mass in gram ➗ by molecular mass
90 ➗ 2=45