Answer to Question #170420 in Inorganic Chemistry for Jurin junior

Question

Answer the following stoichiometry questions by refering to the equation below:

2 KCIO₃ ---> 2 KCI + 3 0₂

i. If 1.50 mol of KCIO₃ decomposes, what is the mass of O₂ that willbe produced?

ii. If 80.0 grams of O₂ was produced, how many moles of KCIO₃ are decomposed?

iii. Find the mass of KCIO₃ needed if we need to produce 2.75 mol of KCI

Answer 1

1. 2moles of KClO3 ---> 3moles of O2

1.50mol of KClO3 ---> 3/2 x 1.50= 2.25mol

1mol of O2 = 32g

2.25mol of O2= 32/1 x 2.25= 72.0g

II. moles of O2= 80.0/32.0 = 2.5moles of O2

3moles of O2 is produced from 2moles of KClO3

2.5moles of O2 will be produced from 2/3 x 2.5 = 1.67mol

3. 2mol of KCl ---> 2mol of KClO3

2.75mol of KCl----> 2.75mol of KClO3

Molar mass of KClO3= 122.5g

Mass= mole x molar mass = 2.75 x 122.5= 336.88g