Answer:
The correct answer is "Hydrochloric Acid".
Step-by-step explanation:
The compound that Mr. pham used in its work is hydrochloroc acid . Hydrochloric acid has many uses, the one that is demonstrated in this question is that it is used to remove rusts and scales from sunstances, especially things made of steel. Hydrochloric acid is used for wide varieties of application in industries.