Question

An acid solution was prepared by dissolving 0.767 dm³ of hydrogen chloride gas in water at STP to make 0.25 dm³ of solution. 18 cm³ of this solution were enough to neutralize 25 cm³ containing 9.864 g of the compound YHCO₃ per liter of solution. Determine

(i) Concentration of the base in g/dm³
(ii) Atomic mass of Y.
(iii) Write the correct formula of the base.

Answer 1

(i) The concentration of the base is 0.221 g/dm³.

(ii) The atomic mass of Y is 22.99 g/mol.

(iii) The correct formula of the base is NaHCO₃.

Step-by-step explanation:

In the given problem, the concentration of the base can be determined by finding the molarity of the solution that neutralizes the acid. The equation for neutralization is
`\(2\text{HCl} + \text{NaHCO₃} \rightarrow \text{CO₂} + \text{H₂O} + 2\text{NaCl}\).` Since 18 cm³ of the acid solution neutralizes 25 cm³ of the base solution containing
`\(9.864 \, \text{g/L}\)`of YHCO₃, we can use the molarity equation to find the concentration of the base in g/dm³. The concentration is calculated as
`\(0.767 \, \text{dm³} * (1)/(25 * 0.018) * 9.864 \, \text{g/L} = 0.221 \, \text{g/dm³}\).`

To find the atomic mass of Y, we need to consider the molar ratio in the balanced equation. In this case, the ratio between NaHCO₃ and YHCO₃ is 1:1. Since the molar mass of NaHCO₃ is 84.01 g/mol, the atomic mass of Y is also 84.01 g/mol.

Therefore, the final answer is:

(i) The concentration of the base is
`\(0.221 \, \text{g/dm³}\).`

(ii) The atomic mass of Y is
`\(84.01 \, \text{g/mol}\).`

(iii) The correct formula of the base is NaHCO₃.