Hydrogen and chlorine react to yield hydrogen chloride: H2 + Cl2 ¡ 2 HCl. How many grams of HCl are formed from reaction of 3.56 g of H2 with 8.94 g of Cl2? Which reactant is limiting?

Verified step by step guidance

1. Calculate the molar mass of H2 and Cl2 using the periodic table.
2. Convert the given masses of H2 and Cl2 to moles by dividing by their respective molar masses.
3. Use the stoichiometry of the balanced chemical equation to determine the mole ratio between H2, Cl2, and HCl.
4. Identify the limiting reactant by comparing the mole ratio of the reactants to the stoichiometric ratio from the balanced equation.
5. Calculate the mass of HCl produced by using the moles of the limiting reactant and the molar mass of HCl.

Key Concepts

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It allows us to calculate the amounts of substances consumed and produced in a reaction based on balanced chemical equations. In this case, the stoichiometric coefficients in the equation H2 + Cl2 → 2 HCl indicate that one mole of hydrogen reacts with one mole of chlorine to produce two moles of hydrogen chloride.

Limiting Reactant

The limiting reactant is the substance that is completely consumed first in a chemical reaction, thus determining the maximum amount of product that can be formed. To identify the limiting reactant, one must compare the mole ratios of the reactants based on the balanced equation and the initial amounts available. In this scenario, calculating the moles of H2 and Cl2 will reveal which reactant limits the formation of HCl.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is essential for converting between grams and moles, which is necessary for stoichiometric calculations. For example, the molar mass of H2 is approximately 2.02 g/mol, and that of Cl2 is about 70.90 g/mol. Knowing these values allows us to determine how many moles of each reactant are present, facilitating the identification of the limiting reactant and the amount of HCl produced.