What do strong and weak acids have in common?

A. Electrical current conduction

B. Reaction with magnesium

C. pH paper test

D. Litmus paper test

All the above

Explanation:

A. Electrical current conduction

Aqueous solutions of both strong and weak acids will conduct an electric current. Weak acids are poorer conductors because they produce fewer ions.

B. Reaction with magnesium

Both strong and weak acids will react with magnesium, although weak acids will react more slowly.

C. pH paper test

Both strong and weak acids will give a colour with pH test paper, although the colours will probably be different.

D. Litmus paper test

Both strong and weak acids will turn blue litmus red.

D. Litmus paper test

Explanation:

The strength of an acid does not effect the color change of the litmus paper.