How many grams of oxygen would be produced if 6.5g of potassium chlorate is decomposed into oxygen and potassium chlorate by heating? 2KCIO3- 3O2+2KCI

1 Answer
Jun 17, 2018

2.55g

Explanation:

Step 1: Find the molar ratio between KClO_3 and O_2

The molar ratio between the two substances are 2 : 3

This comes from the numbers in front of the equation which is the molar ratios

Step 2: Find the number of moles in 6.5g of KClO_3

n = m/M

n = 6.5/(39 + 35.5 + 3 \times 16)

n = 0.0531

Step 3: Use the molar ratio to find number of moles of O_2

n(KClO_3) = 0.0531

n(O_2) = 3/2\timesn(KClO_3)

n(O_2) = 3/2\times0.0531

\thereforen(O_2) = 0.07965

Step 4: Calculate the mass of O_2

n = m/M

0.07965 = m/(16\times2)

m = 0.07965\times16\times2

\therefore m = 2.55g

Hope that makes sense!