The number of moles of hydrogen atom in 6.4g of methane CH4 is 0.4 moles.
To find the number of moles of hydrogen atoms in 6.4 g of methane (CH4), we need to know the molar mass of methane and use the formula for converting mass to moles:
moles = mass / molar mass
The molar mass of methane is 16.04 g/mol, so we can plug in the values and solve:
moles = (6.4 g) / (16.04 g/mol)
moles = 0.4 moles
There are 0.4 moles of hydrogen atoms in 6.4 g of methane. This is because methane is a compound made up of one carbon atom and four hydrogen atoms, and the number of moles of a compound is equal to the total number of moles of all the atoms in the compound.
Since there are four hydrogen atoms in each mole of methane, there are also 0.4 moles of hydrogen atoms in 0.4 moles of methane.