What are the concentrations of hydroxide and hydronium ions in a solution with a ph of 8.3?
2.9 × 10–5 m h3o+ and 3.4 × 10–10 m oh–
3.1 × 10–6 m h3o+ and 3.2 × 10–9 m oh–
5.0 × 10–9 m h3o+ and 2.0 × 10–6 m oh–
6.3 × 10–11 m h3o+ and 1.6 × 10–4 m oh–

The hydroxide concentration is 2*10^-6 M

The hydronium concentration is 5*10^-9 M

Explanation:

Step 1: Data given

pH = 8.3

Step 2: Calculate [H+]

pH = 8.3 = -log [H+]

[H+] = 10^-8.3 = 5*10^-9 M

[H+] = [H3O+] = 5*10^-9 M

Step 3: Calculate pOH

pH + pOH = 14

pOH = 14 -pH = 14 - 8.3 = 5.7

Step 4: Calculate concentration of hydroxide

pOH = -log [OH-] = 5.7

[OH-] = 10^-5.7 = 2*10^-6 M

The hydroxide concentration is 2*10^-6 M

The hydronium concentration is 5*10^-9 M

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.