What is the mass of hydrogen that will react with 0.203 g of Li to form LiH?

Question

Quizplus · Accepted Answer

The balanced chemical equation of the reaction between Li and H₂ to form LiH is:

2Li + H₂ → 2LiH

From the equation, we can see that 2 moles of Li react with 1 mole of H₂ to form 2 moles of LiH.

The molar mass of Li is 6.941 g/mol, and the molar mass of H₂ is 2.016 g/mol.

First, we need to find the number of moles of Li present in 0.203 g of Li:

moles of Li = mass of Li / molar mass of Li
moles of Li = 0.203 g / 6.941 g/mol
moles of Li = 0.0293 mol

Since 2 moles of Li react with 1 mole of H₂, we need to divide the number of moles of Li by 2 to find the number of moles of H₂ required:

moles of H₂ = moles of Li / 2
moles of H₂ = 0.0293 mol / 2
moles of H₂ = 0.01465 mol

Finally, we can find the mass of H₂ by multiplying the number of moles by the molar mass of H₂:

mass of H₂ = moles of H₂ x molar mass of H₂
mass of H₂ = 0.01465 mol x 2.016 g/mol
mass of H₂ = 0.0295 g

Therefore, the mass of hydrogen that will react with 0.203 g of Li to form LiH is 0.0295 g, which corresponds to choice B.

What Is the Mass of Hydrogen That Will React with 0.203