How many moles of methane are produced when 25.1 moles of carbon dioxide gas react with excess hydrogen gas

Answer 1

CO2 + 4H2 ==> CH4 + 2H2O
You can convert mols of ANYTHING to mols ANOTHER THING in the equation by using the coefficients in the balanced equation. See the following.

25.1 mols CO2 x (1 mol CH4/1 mol CO2) = 25.1 x 1/1 = ?