Question

balancing act
name laura taya
atoms are not created or destroyed during a chemical reaction. scientists know that there must be the same number of atoms on each side of the equation. to balance the chemical equation, you must add coefficient in front of the chemical formulas in the equation. you cannot add or change subscripts!

1. determine number of atoms for each element.
2. pick an element that is not equal on both sides of the equation.
3. add a coefficient in front of the formula with that element and adjust your counts.
4. continue adding coefficients to get the same number of atoms of each element on each side.

try these:
ca + o₂ → 2cao
ca = 1
o = 2
ca = 1
o = 1
n₂ + h₂ → nh₃
n =
h =
n =
h =
cu₂o + c → cu + co₂
cu =
o =
c =
cu =
o =
c =
h₂o₂ → h₂o + o₂
h =
o =
h =
o =

Explanation:

Step1: Balance $Ca + O_2

ightarrow CaO$
For the equation $Ca + O_2
ightarrow CaO$, there is 1 Ca and 2 O on the left - hand side, and 1 Ca and 1 O on the right - hand side. To balance the oxygen atoms, we put a coefficient of 2 in front of CaO, then we have 2 Ca on the right - hand side. So we put a 2 in front of Ca on the left - hand side. The balanced equation is $2Ca+O_2
ightarrow 2CaO$.

Step2: Balance $N_2 + H_2

ightarrow NH_3$
There are 2 N and 2 H on the left - hand side and 1 N and 3 H on the right - hand side. First, balance the nitrogen atoms. Put a 2 in front of $NH_3$, then we have 6 H on the right - hand side. So we put a 3 in front of $H_2$. The balanced equation is $N_2 + 3H_2
ightarrow 2NH_3$.

Step3: Balance $Cu_2O + C

ightarrow Cu+CO_2$
On the left - hand side, we have 2 Cu, 1 O and 1 C. On the right - hand side, we have 1 Cu, 2 O and 1 C. First, balance the copper atoms. Put a 2 in front of Cu. Then, to balance the oxygen atoms, we need 2 moles of $Cu_2O$. So the balanced equation is $2Cu_2O + C
ightarrow 4Cu+CO_2$.

Step4: Balance $H_2O_2

ightarrow H_2O+O_2$
On the left - hand side, we have 2 H and 2 O. On the right - hand side, we have 2 H and 3 O. Put a 2 in front of $H_2O_2$, 2 in front of $H_2O$. The balanced equation is $2H_2O_2
ightarrow 2H_2O + O_2$.

Answer:

$2Ca+O_2
ightarrow 2CaO$
$N_2 + 3H_2
ightarrow 2NH_3$
$2Cu_2O + C
ightarrow 4Cu+CO_2$
$2H_2O_2
ightarrow 2H_2O + O_2$