MSJChem – Topic 1 – Balancing chemical equations
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Balancing chemical equations
Balance the following chemical equations. When each equation is balanced,
calculate the sum of coefficients in the equations.
1) CH4(g) + O2(g)  CO2(g) + H2O(l)
2) C3H8(g) + O2(g)  CO2(g) + H2O(l)
3) CH3OH(l) + O2(g)  CO2(g) + H2O(l)
4) Mg(s) + HCl(aq)  MgCl2(aq) + H2(g)
5) CaCO3(s) + HCl(aq)  CaCl2(aq) + H2O(l) + CO2(g)
6) NaCl(aq) + CaO(aq)  CaCl2(aq) + Na2O(aq)
7) Al(s) + Fe3O4(s) Al2O3(s) + Fe(s)
8) Mg3N2(s) + H2SO4(aq)  MgSO4(aq) + (NH4)2SO4(aq)
9) Fe2O3(s) + C(s)  Fe(s) + CO(g)
10) Al(OH)3(s) + H2SO4(aq)  Al2(SO4)3(aq) + H2O(l)
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MSJChem – Topic 1 – Balancing chemical equations
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Answers:
1) CH4(g) + 2O2(g)  CO2(g) + 2H2O(l)
Sum of coefficients: 6
2) C3H8(g) + 5O2(g)  3CO2(g) + 4H2O(l)
Sum of coefficients: 13
3) 2CH3OH(l) + 3O2(g)  2CO2(g) + 4H2O(l)
Sum of coefficients: 11
4) Mg(s) + 2HCl(aq)  MgCl2(aq) + H2(g)
Sum of coefficients: 5
5) CaCO3(s) + 2HCl(aq)  CaCl2(aq) + H2O(l) + CO2(g)
Sum of coefficients: 6
6) 2NaCl(aq) + CaO(aq)  CaCl2(aq) + Na2O(aq)
Sum of coefficients: 5
7) 8Al(s) + 3Fe3O4(s) 4Al2O3(s) + 9Fe(s)
Sum of coefficients: 24
8) Mg3N2(s) + 4H2SO4(aq)  3MgSO4(aq) + (NH4)2SO4(aq)
Sum of coefficients: 9
9) Fe2O3(s) + 3C(s)  2Fe(s) + 3CO(g)
Sum of coefficients: 9
10) 2Al(OH)3(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 6H2O(l)
Sum of coefficients: 12
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