Given the reaction:2KClO3(s) → 2KCl(s) + 3O2(g)How many moles of KClO3 must completely react to pr

January 2019 NY Regents Chemistry Exam

35 Given the reaction:
2KClO3(s) → 2KCl(s) + 3O2(g)
How many moles of KClO3 must completely react to produce 6 moles of O2?
(1) 1 mole

(2) 2 moles

(3) 6 moles

(4) 4 moles

Solution:The coefficients in the equation are 3 for O2 and 2 for KClO3. This means 3 moles of O2 will be produced when 2 moles of KClO3 are reacted. Therefore, for 6 moles of O2 which is twice the amount, we would get 2*2= 4moles of KClO3.

Answer:4

Prepare for the Chemistry Regents Exam: HERE