Calculate [H+] of 0.100M HNO2 (Ka = 6.0×10-4

Sure, to calculate the concentration of H+ ions ([H+]) in a solution of nitrous acid (HNO2), we can use the ionization constant (Ka) and the initial concentration of the acid. Here are the steps:

1. Write the ionization equation for HNO2: HNO2 ⇌ H+ + NO2-

2. Write the expression for the ionization constant (Ka): Ka = [H+][NO2-] / [HNO2]

3. Since the initial concentration of HNO2 is 0.100 M and we assume that x M of it ionizes, we can write the concentrations of all species at equilibrium: [HNO2] = 0.100 - x [H+] = x [NO2-] = x

4. Substitute these concentrations into the Ka expression: 6.0×10^-4 = x*x / (0.100 - x)

5. This is a quadratic equation in the form of ax^2 + bx + c = 0. However, if x is small enough compared to 0.100, we can simplify it by assuming that (0.100 - x) ≈ 0.100. This is often the case for weak acids, and it makes the calculation easier: 6.0×10^-4 ≈ x^2 / 0.100

6. Solve this equation for x, which represents [H+]: x = sqrt(6.0×10^-4 * 0.100) x = sqrt(6.0×10^-5) x = 7.75×10^-3 M

So, the [H+] in the solution is approximately 7.75×10^-3 M.