To balance the given chemical equation, we need to first identify the reactants and products. The given equation is:
\[ \text{In} + \text{HNO}_3 \rightarrow \text{Zn(NO}_3)_2 + \text{H}_2 \]
Analyzing the species involved:
- Reactants: In, HNO₃
- Products: Zn(NO₃)₂, H₂
Now let's determine the number of each atom in the reactants and products:
- In: 1 (reactant side)
- H: 1 (in HNO₃, reactant side)
- N: 1 (in HNO₃, reactant side)
- O: 3 (in HNO₃, reactant side)
On the product side we have:
- Zn: 1 (in Zn(NO₃)₂)
- N: 2 (in Zn(NO₃)₂, since there are 2 nitrate ions)
- O: 6 (in Zn(NO₃)₂, 3 oxygen per nitrate multiplied by 2)
- H: 2 (in H₂)
Let's list the atoms again:
Reactants:
- In: 1
- H: 1
- N: 1
- O: 3
Products:
- Zn: 1
- H: 2
- N: 2
- O: 6
To balance the equation, we can see the need for adjustments.
-
We need 2 nitrogen atoms on the reactant side (currently have only 1), so we will have to double HNO₃: \[ \text{In} + 2 \text{HNO}_3 \]
-
This gives us:
- H: 2 (since we now have 2 HNO₃)
- N: 2 (2 from the 2 HNO₃)
- O: 6 (2 HNO₃ gives 6 O, which matches the 6 in products).
Now, we rewrite the updated equation:
\[ \text{In} + 2 \text{HNO}_3 \rightarrow \text{Zn(NO}_3)_2 + \text{H}_2 \]
Balancing:
- In: 1 on each side
- H: 2 on each side
- N: 2 on each side
- O: 6 on each side
- Zn: Now the zinc should also be included in the reactants since it’s part of the products
The correct balanced equation should be:
\[ \text{Zn} + 2 \text{HNO}_3 \rightarrow \text{Zn(NO}_3)_2 + \text{H}_2 \]
Thus, to balance the original equation with respect to the addition of zinc and adjustment of \( \text{HNO}_3 \):
Changes made:
- Coefficient of HNO₃ modified from 1 to 2.
- Added Zn on the reactant side.
In total, two coefficients need to be adjusted (change one and add one) to balance the equation.