Question

Sodium metal and water react to form hydrogen and sodium hydroxide. If 5.98 g of sodium react with water to form 0.26 g of hydrogen and 10.40 g of sodium hydroxide, what mass of water was consumed in the reaction

Answer 1

The mass of water that was consumed in the reaction = 4.68 grams

Calculation and explanation

According to the law of mass conservation  the mass of the product in a chemical reaction must be equal to mass of product.

mass of the product= mass of hydrogen + mass of sodium hydroxide

mass of product=0.26 g + 10.40 =10.66 grams

mass of reactant therefore  must be= 10.66 grams

mass of reactant = mass of  sodium metal + mass of water

let mass of H2O be represented by

10.66 = 5.98 g  + Y

like terms together Y= 10.66 -5.98= 4.68 grams of  water