Question

Chemistry is not always as simple as we are learning it, of course. Many times, reactions are linked, and the products of one reaction immediately become the reactants in another one. For example, 2 KClO3 → 3 O2 + 2 KCl, and then the oxygen produced goes on to make 2 Mg + O2 → 2 MgO. Suppose you begin with exactly 4 moles of potassium chlorate. If so, how much magnesium oxide can you produce? NOTE: All numbers located immediately after elemental symbols below should be considered subscripts.

A. 4 moles
B. 12 moles
C. 6 moles
D. 2 moles
E. none of the above

Answer 1

Answer:

It can be produced, 12 moles of MgO.

Option B

Explanation:

2 KClO₃ → 3O₂ + 2 KCl

Ratio in this reaction is 2:3

In the begining, I make 3 moles of oxygen, that came from 2moles of chlorate. If I have 4 moles of salt, let's make a rule of three.

2 moles of salt ___ make __3 moles of O₂

4 moles of salt ___ make (4 .3) /2 = 6 moles of O₂

2 Mg + O2 → 2 MgO.

From 1 mol of oxygen, I can make 2 moles of oxygen.

If I have 6 moles, I would make the double, though.