Take care to use the word 'dilute' correctly ... the pH of the solution decreases by 1 unit. A solution of 1 g/dm 3 hydrochloric acid has a pH of 1.6. Predict its pH when it is diluted to 0.1 ...

Muriatic acid can clear out stubborn clogs, but it probably shouldn't be your first choice. There's a lot you need to prepare before using it.