Question

H2SO4 is added to a large beaker of water. How is the solution different from the original water?
The solution turns blue litmus to red.
The solution turns phenolphthalein pink.
The solution has fewer hydrogen ions.
The solution has more hydroxide ions.

Answer 1

The correct choice is: The solution turns blue litmus to red.

Reason: H2SO4 is an acid, so adding it to water increases [H+] and decreases [OH−]. Acidic solutions turn blue litmus red; phenolphthalein turns pink in basic (not acidic) solutions, so it would be colorless here.