Question

A 5.37 g mixture of sodium chloride and sodium carbonate is heated to decompose the sodium carbonate into sodium oxide and carbon dioxide according to the following chemical equation.

Na₂CO₃ → Na₂O + CO₂

The sodium chloride will not decompose. If the final mixture has a mass of 4.03 g, what was the percent sodium carbonate in the original mixture?

Hint: Consider the Law of Conservation of Matter - the mass of reactants must equal the mass of products. However, if one of the products is a gas it could be difficult to weigh. Use the mass of gas to determine the mass of sodium carbonate. Then calculate the percent of sodium carbonate in the mixture.

Mass of gas
g

Mass of Na₂CO₃
g

Percent of Na₂CO₃
%

Answer 1

- Aus] given at mih. mass of Nocl + Naz coz = 5.374. after decomposition of Naz.com mass of Nald & Nag O= 4.039 cog vis vapaunise during Ron Na2CO3 N920 + CO2 Solution applied hawe of Conservation of mass or Matter. Caften and befon Reaction). Inibal mass of NaCl + Ne los = mass offracl + NO20)+ may of Co2 we knaul, 5.379 = 40039 + mass of Co2 mass of CO2 = 1.349. moles of CO2 = 1.39g = 0.03 mol 4ug/mal

Na₂CO Nazo & Co2 applied POAC Rule. moles of Nar com a moles of Co2 cofficient officient mass of Na₂CO3 = 0.03 Molar mass XI mass of N9₂00, 0.03 mol 106 g/mol mass of Na₂CO3 = 3.239 mass % = mass of NaCom x 100 Total mass (Nacht Non Cop) = 3.239 xloo - 60.12% 5.379 b) Ansueurs al mass of CO2 = 1.349 b) mass of Naz Cog= 3.239 c) mass % of NLCO₃ = 60.12%