The one with the highest pH would be a solution with 100 mL of water and also 20 mL of 0.1 M NaOH is added. Solutions without buffers would have the highest pH since the resistance to change is very low. Hope this answers the question.
The answer is dissolved salts
D because yes it works very slow
The answer is (4) synthesis. Synthesis reaction means that two or more reactants combine directly to one production. Substitution or single replacement means that one element of a compound is replaced by another element. Double replacement means that two ionic reactants exchange ions to form two new productions.