To determine the amount of hydrogen and oxygen needed to produce 25 grams of water, we can use the balanced chemical equation for the formation of water:2H2 + O2 2H2OFirst, we need to find the molar mass of water H2O :1 mole of H2O = 2 x 1.008 g/mol for H + 1 x 16.00 g/mol for O = 18.016 g/molNow, we can find out how many moles of water are in 25 grams:25 g H2O 1 mol H2O / 18.016 g H2O = 1.387 moles H2OFrom the balanced equation, we can see that 2 moles of H2 react with 1 mole of O2 to produce 2 moles of H2O. Therefore, we need:1.387 moles H2O 2 moles H2 / 2 moles H2O = 1.387 moles H21.387 moles H2O 1 mole O2 / 2 moles H2O = 0.6935 moles O2Now, we can convert moles of H2 and O2 to grams:1.387 moles H2 2.016 g/mol for H2 = 2.796 g H20.6935 moles O2 32.00 g/mol for O2 = 22.20 g O2So, the student would need 2.796 grams of hydrogen and 22.20 grams of oxygen to produce 25 grams of water.