Answer
1.78 x 10^25 molecules H2
Work Step by Step
We have amount methane and need molecules of hydrogen, so we use molar ratio of moles hydrogen to moles methane.
Get the molar mass of methane by adding 1 * molar mass carbon + 4 * molar mass of hydrogen.
Using the initial amount, divide it by number of grams in 1 mole. Then, multiply that by the molar ratio.