Question

0.005 M acid solution has 5 pH.The %ionisation of acid is?

Answer 1

The % ionization of the acid is 0.2%.

Answer 2

Explanation of the solution:

1. Calculate Hydrogen Ion Concentration ([H+]): The pH of the solution is given as 5. The hydrogen ion concentration can be calculated using the formula: $$[H^+] = 10^{-\text{pH}}$$ Substituting the given pH value: $$[H^+] = 10^{-5} \text{ M}$$

2. Calculate Percentage Ionization: Percentage ionization ($\\alpha$) is defined as the ratio of the concentration of ionized acid (which is equal to $[H^+]$ for a monobasic acid) to the initial concentration of the acid, multiplied by 100. $\\text{% Ionization} = \\frac{[H^+]}{\\text{Initial Concentration of Acid}} \\times 100\$$ Given initial concentration of acid = 0.005 M. \$$\\text{% Ionization} = \\frac{10^{-5} \\text{ M}}{0.005 \\text{ M}} \\times 100\$$ Convert 0.005 M to scientific notation: 0.005 = 5 \times 10^{-3}$M.$\text{% Ionization} = \frac{10^{-5}}{5 \times 10^{-3}} \times 100$$\text{% Ionization} = \frac{1}{5} \times 10^{-5 - (-3)} \times 100$$\text{% Ionization} = 0.2 \times 10^{-2} \times 100$$\text{% Ionization} = 0.2 \times 0.01 \times 100$$\text{% Ionization} = 0.002 \times 100$$\text{% Ionization} = 0.2%$