Question

1. How much calcium oxide would be made by the thermal decomposition of 25 grams of calcium carbonate?

CaCO3 -> CaO + CO2

2.How much oxygen gas can be produced through the decomposition of potassium chlorate (KClO3) if 194.7 g of potassium chlorate is heated and fully decomposes? The equation for this reaction must be balanced first.

KClO3 (s) -> KCl (s) + O2 (g)

Answer 1

1. 14g of CaO

2. 76.29g of O2

Step-by-step explanation:

1. The equation for the thermal decomposition of calcium carbonate CaCO3 is given below:

CaCO3 —> CaO + CO2

Next, let us calculate the mass of CaCO3 decomposed and the mass of CaO produced from the balanced equation above. This is illustrated below:

Molar Mass of CaCO3 = 40 + 12 + (16x3) = 40 + 12 + 48 = 100g/mol

Molar Mass of CaO = 40 + 16 = 56g/mol

Now, we can easily find the mass of calcium oxide (CaO) produced from the decomposition of 25g of calcium carbonate (CaCO3) as follow:

From the balanced equation above,

100g of CaCO3 produced 56g of CaO.

Therefore, 25g of CaCO3 will produce = (25 x 56)/100 = 14g of CaO.

2. The balance equation for the decomposition of KClO3 is given below:

2KClO3 —> 2KCl + 3O2

Next, let us calculate the mass of KClO3 that decomposed and the mass of O2 produced from the balanced equation above. This is illustrated below:

Molar Mass of KClO3 = 39 + 35.5 + (16x3) = 39 + 35.5 + 48 = 122.5g/mol

Mass of KClO3 from the balanced equation = 2 x 122.5 = 245g

Molar Mass of O2 = 16x2 = 32g/mol

Mass of O2 from the balanced equation = 3 x 32 = 96g

Now, we can calculate the mass of oxygen (O2) produced from the decomposition of 194.7 g of potassium chlorate (KClO3) as follow:

From the balanced equation above,

245g of KClO3 produced 96g of O2.

Therefore, 194.7g of KClO3 will produce = (194.7 x 96)/245 = 76.29g of O2.