Stoichiometry?

Question

What are the ratios for the following?

1)water to manganeese(II) chloride in the reaction: HCl + MnO2 ==> H2O + MnCl2 + Cl2
2)copper to iron in the reaction: Fe + CuSO4 ==> FeSO4 + Cu
3)iron to carbon dioxide in the reaction: Fe2O3 + CO ==> Fe + CO2
4)sodium to oxygen in the reaction: Na + O2 ==> Na2O

Answer 1

1) 4HCl + MnO2 ==>2H2O + MnCl2 + Cl2

2) Fe + CuSO4 ==> FeSO4 + Cu

3) Fe2O3 +3CO ==>2Fe +3CO2

4) 4Na + O2 ==>2Na2O

Answer 2

To establish the ratios between entities in a chemical equation, we use the coefficients of each.

1)water to manganeese(II) chloride in the reaction: HCl + MnO2 ==> H2O + MnCl2 + Cl2

There is 1 mole of H2O and 1 mole of MnCl2.
Thus, 1 mol H2O : 1 mol MnCl2, or simply, 1:1.

2)copper to iron in the reaction: Fe + CuSO4 ==> FeSO4 + Cu

1 mole of Cu and 1 mole of Fe; again, 1:1.

3)iron to carbon dioxide in the reaction: Fe2O3 + CO ==> Fe + CO2

1 mole of Fe and 1 mole of CO2; 1:1

4)sodium to oxygen in the reaction: Na + O2 ==> Na2O

1 mole of Na and 1 mole of O2; 1:1

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All the ratios are 1:1, or simply, 1 (1 divided by 1 is 1).

Answer 3

1)water to manganese(II) chloride in the reaction:
4HCl + MnO2 ==> 2H2O + MnCl2 + Cl2
H2O : MnCl2 :: 2 : 1
2)copper to iron in the reaction: Fe + CuSO4 ==> FeSO4 + Cu
Fe : Cu :: 1 : 1
3)iron to carbon dioxide in the reaction: Fe2O3 + 3CO ==> 2Fe + 3CO2
Fe : CO2 :: 2 : 3
4)sodium to oxygen in the reaction: 4Na + O2 ==> 2Na2O
Na : O2 :: 4 :1