Which of the following solutions will have the lowest pH, assuming complete dissociation? Remember: pH = -log10[H3O+(aq)], pOH = -log10[OH-(aq)] and pH + pOH = 14.00 Group of answer choices 1 M solution of HNO3 0.3 M solution of H2SO4 1.4 M solution of CsOH 0.8 M solution of Mg(OH)2

The pH of a solution is determined by the concentration of hydronium ions (H3O+) in the solution. The more hydronium ions, the lower the pH.

1. HNO3 is a strong acid that will completely dissociate in water to form H3O+ and NO3-. Therefore, a 1 M solution of HNO3 will have a [H3O+] of 1 M. The pH of this solution will be -log10(1) = 0.

2. H2SO4 is also a strong acid that will completely dissociate in water. However, because each molecule of H2SO4 produces two H3O+ ions, a 0.3 M solution of H2SO4 will have a [H3O+] of 0.6 M. The pH of this solution will be -log10(0.6) = 0.22.

3. CsOH is a strong base that will completely dissociate in water to form Cs+ and OH-. The pOH of a 1.4 M solution of CsOH will be -log10(1.4) = 0.15. Using the formula pH + pOH = 14, the pH of this solution will be 14 - 0.15 = 13.85.

4. Mg(OH)2 is a strong base that will completely dissociate in water. However, because each molecule of Mg(OH)2 produces two OH- ions, a 0.8 M solution of Mg(OH)2 will have a [OH-] of 1.6 M. The pOH of this solution will be -log10(1.6) = 0.20. Using the formula pH + pOH = 14, the pH of this solution will be 14 - 0.20 = 13.80.

Therefore, the 1 M solution of HNO3 will have the lowest pH.