You can calculate the excess reactant by subtracting the mass of excess reagent consumed from the total mass of reagent given therefore, The answer: Theoretical yield is 121.60 g of NH₃ Excess reactant is H₂ Rate limiting reactant is N₂ explanation: 100 g of Nitrogen 100 g of hydrogen We are required to identify the theoretical yield of the reaction, the excess reactant and the rate limiting reagent. We first write the equation for the reaction between nitrogen and hydrogen; N₂ + 3H₂ → 2NH₃ From the reaction 1 mole of nitrogen reacts with 3 moles of Hydrogen gas. Secondly we determine the moles of nitrogen gas given and hydrogen gas given; Moles of Nitrogen gas Moles = Mass ÷ Molar mass Molar mass of nitrogen gas = 28.0 g/mol Moles of Nitrogen gas = 100 g ÷ 28 g/mol 3.57 moles Moles of Hydrogen gas Molar mass of Hydrogen gas = 2.02 g/mol Moles = 100 g ÷ 2.02 g/mol = 49.50 moles From the mole ratio given by the equation, 1 mole of nitrogen requires 3 moles of Hydrogen gas. Thus, 3.57 moles of Nitrogen gas requires (3.57 × 3) 10.71 moles of Hydrogen gas. This means, Nitrogen gas is the rate limiting reagent and hydrogen gas is the excess reactant. Third calculate the theoretical yield of the reaction. 1 mole of nitrogen reacts to from 2 moles of ammonia gas Therefore; Moles of ammonia gas produced = Moles of nitrogen × 2 = 3.57 moles × 2 = 7.14 moles But; molar mass of Ammonia gas is = 17.03 g/mol Therefore; Mass of ammonia gas produced = 7.14 moles × 17.03 g/mol = 121.59 g = 121.60 g Thus, the theoretical amount of ammonia gas produced is 121.60 g
The number of valence electrons in an atom is reflected by its position in the periodic table of the elements (see the periodic table in the Figure below). Across each row, or period, of the periodic table, the number of valence electrons in groups 1–2 and 13–18 increases by one from one element to the next
