Final answer:
When 20.0g of copper (II) nitrate is heated, approximately 8.48 g of copper (II) oxide and 9.81 g of nitrogen dioxide would be produced.
Step-by-step explanation:
When copper (II) nitrate is heated, it decomposes to produce copper (II) oxide, nitrogen dioxide, and oxygen. The balanced chemical equation for this decomposition is 2Cu(NO3)2(s) → 2CuO(s) + 4NO2(g) + O2(g). To determine the mass of copper (II) oxide and nitrogen dioxide produced from heating 20.0g of copper (II) nitrate, we first calculate the molar mass of copper (II) nitrate (Cu(NO3)2) and copper (II) oxide (CuO).
Molar mass of Cu(NO3)2 is approximately 187.55 g/mol and for CuO it is approximately 79.55 g/mol. Applying the stoichiometry of the reaction, the mole ratio of copper (II) nitrate to copper (II) oxide is 1:1. So, the moles of copper (II) nitrate we start with equals 20.0 g ÷ 187.55 g/mol, which equals approximately 0.1066 moles. These moles will give an equal number of moles of CuO which will then be multiplied with the molar mass of CuO to find the mass of copper (II) oxide produced.
0.1066 moles of CuO × 79.55 g/mol gives approximately 8.48 g of CuO.
Using a similar approach, we calculate the mass of NO2 produced. The mole ratio of copper (II) nitrate to nitrogen dioxide is 1:2. Therefore, 0.1066 moles of copper (II) nitrate will produce twice as many moles of NO2, which is approximately 0.2132 moles. Given the molar mass of NO2 is approximately 46.01 g/mol, the mass of NO2 produced is 0.2132 moles × 46.01 g/mol, which equals approximately 9.81 g of NO2.