Question

practice: balancing equation
show all work on a separate sheet of paper. place coefficient final answers. leave coefficients of \1\ blank.

1. h₂ + o₂ → h₂o
2. h₃po₄ + koh → k₃po₄ + h₂o
3. k + b₂o₃ → k₂o + b
4. hcl + naoh → nacl + h₂o
5. na + nano₃ → na₂o + n₂
6. c + s₈ → cs₂
7. na + o₂ → na₂o₂
8. n₂ + o₂ → n₂o₅
9. h₃po₄ + mg(oh)₂ → mg₃(po₄)₂
10. naoh + h₂co₃ → na₂co₃
11. koh + hbr → kbr + h₂o
12. h₂ + o₂ → h₂o₂
13. na + o₂ → na₂o
14. al(oh)₃ + h₂co₃ → al₂(co₃)

Explanation:

Step1: Balance hydrogen in $H_2 + O_2

ightarrow H_2O$
We need 2 moles of $H_2$ to get 4 hydrogen - atoms on the left - hand side to match 2 moles of $H_2O$ on the right - hand side. So the balanced equation is $2H_2+O_2
ightarrow 2H_2O$.

Step2: Balance $H_3PO_4 + KOH

ightarrow K_3PO_4 + H_2O$
For potassium, we need 3 moles of $KOH$. For hydrogen and oxygen balance, we get $H_3PO_4 + 3KOH
ightarrow K_3PO_4+3H_2O$.

Step3: Balance $K + B_2O_3

ightarrow K_2O + B$
To balance potassium, we need 6 moles of $K$. Then the balanced equation is $6K + B_2O_3
ightarrow 3K_2O+2B$.

Step4: Balance $HCl + NaOH

ightarrow NaCl + H_2O$
The equation is already balanced as it is: $HCl + NaOH
ightarrow NaCl + H_2O$.

Step5: Balance $Na+NaNO_3

ightarrow Na_2O + N_2$
To balance nitrogen, we need 2 moles of $NaNO_3$. Then to balance sodium and oxygen, the balanced equation is $10Na + 2NaNO_3
ightarrow 6Na_2O+N_2$.

Step6: Balance $C + S_8

ightarrow CS_2$
We need 8 moles of $C$ and 4 moles of $CS_2$ to balance sulfur. The balanced equation is $8C + S_8
ightarrow 8CS_2$.

Step7: Balance $Na+O_2

ightarrow Na_2O_2$
The balanced equation is $2Na + O_2
ightarrow Na_2O_2$.

Step8: Balance $N_2 + O_2

ightarrow N_2O_5$
To balance oxygen, we need 5 moles of $O_2$ and 2 moles of $N_2O_5$. The balanced equation is $2N_2+5O_2
ightarrow 2N_2O_5$.

Step9: Balance $H_3PO_4+Mg(OH)_2

ightarrow Mg_3(PO_4)_2 + H_2O$
We need 2 moles of $H_3PO_4$ and 3 moles of $Mg(OH)_2$. Then the balanced equation is $2H_3PO_4 + 3Mg(OH)_2
ightarrow Mg_3(PO_4)_2+6H_2O$.

Step10: Balance $NaOH + H_2CO_3

ightarrow Na_2CO_3 + H_2O$
We need 2 moles of $NaOH$. The balanced equation is $2NaOH + H_2CO_3
ightarrow Na_2CO_3+2H_2O$.

Step11: Balance $KOH + HBr

ightarrow KBr + H_2O$
The equation is already balanced: $KOH + HBr
ightarrow KBr + H_2O$.

Step12: Balance $H_2+O_2

ightarrow H_2O_2$
The balanced equation is $H_2+O_2
ightarrow H_2O_2$.

Step13: Balance $Na + O_2

ightarrow Na_2O$
We need 4 moles of $Na$ and 2 moles of $Na_2O$. The balanced equation is $4Na+O_2
ightarrow 2Na_2O$.

Step14: Balance $Al(OH)_3 + H_2CO_3

ightarrow Al_2(CO_3)_3+H_2O$
We need 2 moles of $Al(OH)_3$ and 3 moles of $H_2CO_3$. Then the balanced equation is $2Al(OH)_3+3H_2CO_3
ightarrow Al_2(CO_3)_3 + 6H_2O$.

Answer:

1. $2H_2+O_2

ightarrow 2H_2O$

1. $H_3PO_4 + 3KOH

ightarrow K_3PO_4+3H_2O$

1. $6K + B_2O_3

ightarrow 3K_2O+2B$

1. $HCl + NaOH

ightarrow NaCl + H_2O$

1. $10Na + 2NaNO_3

ightarrow 6Na_2O+N_2$

1. $8C + S_8

ightarrow 8CS_2$

1. $2Na + O_2

ightarrow Na_2O_2$

1. $2N_2+5O_2

ightarrow 2N_2O_5$

1. $2H_3PO_4 + 3Mg(OH)_2

ightarrow Mg_3(PO_4)_2+6H_2O$

1. $2NaOH + H_2CO_3

ightarrow Na_2CO_3+2H_2O$

1. $KOH + HBr

ightarrow KBr + H_2O$

1. $H_2+O_2

ightarrow H_2O_2$

1. $4Na+O_2

ightarrow 2Na_2O$

1. $2Al(OH)_3+3H_2CO_3

ightarrow Al_2(CO_3)_3 + 6H_2O$