What mass of sodium chloride would be decomposed by 9.8 g of sulphuric acid if 12 g of sodium bisulphate and 2.75 g of hydrogen chloride were produced in a reaction?

Options

A. 14.75 g
B. 3.8 g
C. 4.95 g
D. 2.2 g

Explanation

To solve the problem of determining the mass of sodium chloride (NaCl) decomposed by 9.8 g of sulfuric acid (H2SO4), we can follow these steps:

### Step-by-Step Solution:

1. **Write the Balanced Chemical Equation**:
The reaction between sodium chloride and sulfuric acid can be represented as:
\[ \text{NaCl} + \text{H}_2\text{SO}_4 \rightarrow \text{NaHSO}_4 + \text{HCl} \]

2. **Apply the Law of Conservation of Mass**:
According to the law of conservation of mass, the mass of the reactants must equal the mass of the products. Therefore, we can express this as:
\[ \text{mass of NaCl} + \text{mass of H}_2\text{SO}_4 = \text{mass of NaHSO}_4 + \text{mass of HCl} \]

3. **Substitute the Known Values**:
We know:
- Mass of H2SO4 = 9.8 g
- Mass of NaHSO4 = 12 g
- Mass of HCl = 2.75 g

Plugging these values into the equation gives:
\[ \text{mass of NaCl} + 9.8 \, \text{g} = 12 \, \text{g} + 2.75 \, \text{g} \]

4. **Calculate the Mass of NaCl**:
Rearranging the equation to solve for the mass of NaCl:
\[ \text{mass of NaCl} = (12 \, \text{g} + 2.75 \, \text{g}) - 9.8 \, \text{g} \]

Now, performing the calculation:
\[ \text{mass of NaCl} = 14.75 \, \text{g} - 9.8 \, \text{g} = 4.95 \, \text{g} \]

5. **Final Answer**:
Therefore, the mass of sodium chloride decomposed is:
\[ \text{mass of NaCl} = 4.95 \, \text{g} \]