To determine the amount of calcium oxide (CaO) required to neutralize a given quantity of sulfuric acid (H₂SO₄), we can follow these steps:
1. Write the balanced chemical equation:
The neutralization reaction of calcium oxide (CaO) with sulfuric acid (H₂SO₄) is given by:
[tex]\[
\text{CaO} + \text{H}_2\text{SO}_4 \rightarrow \text{CaSO}_4 + \text{H}_2\text{O}
\][/tex]
From this equation, we see that 1 mole of CaO reacts with 1 mole of H₂SO₄.
2. Determine the number of moles of H₂SO₄:
The formula to calculate the number of moles is:
[tex]\[
\text{Number of moles} = \text{Volume} \times \text{Concentration}
\][/tex]
Given:
- Volume of H₂SO₄ = 0.5 L
- Concentration of H₂SO₄ = 0.25 mol/L
Substituting the values:
[tex]\[
\text{Moles of H₂SO₄} = 0.5 \, \text{L} \times 0.25 \, \text{mol/L} = 0.125 \, \text{mol}
\][/tex]
3. Determine the number of moles of CaO needed:
From the balanced equation, we see that the moles of CaO needed are equal to the moles of H₂SO₄, thus:
[tex]\[
\text{Moles of CaO} = 0.125 \, \text{mol}
\][/tex]
4. Find the molar mass of CaO:
The molar mass of CaO is calculated by adding the atomic masses of calcium (Ca) and oxygen (O):
- Atomic mass of Ca = 40 g/mol
- Atomic mass of O = 16 g/mol
Therefore:
[tex]\[
\text{Molar mass of CaO} = 40 \, \text{g/mol} + 16 \, \text{g/mol} = 56 \, \text{g/mol}
\][/tex]
5. Calculate the mass of CaO needed:
The formula to calculate the mass is:
[tex]\[
\text{Mass} = \text{Moles} \times \text{Molar mass}
\][/tex]
Substituting the values:
[tex]\[
\text{Mass of CaO} = 0.125 \, \text{mol} \times 56 \, \text{g/mol} = 7 \, \text{g}
\][/tex]
Therefore, 7 grams of calcium oxide (CaO) would be needed to neutralize 0.5 litre of battery acid (H₂SO₄) with a concentration of 0.25 mol/L.
