pH, acids and bases

Front

What does it indicate if blue litmus paper remains blue when placed in a substance?

Back

The substance is a base.

Front

What type of solution has more H3O+ ions than OH- ions?

Back

Solutions with a pH lower than 7.

Front

What color does Congo red turn in the presence of an acid?

Back

Blue.

Front

Which indicator is best for determining the pH of vinegar?

Back

Bromothymol blue.

Front

What is the product of the reaction between H3O+ and OH-?

Back

Water.

Front

What is the pH range of acidic solutions?

Back

pH less than 7.

Front

What is the pH range of basic solutions?

Back

pH greater than 7.

Front

What is the neutral pH value?

Back

pH of 7.

Front

What does a pH of 7 indicate about a solution?

Back

The solution is neutral.

Front

What is the role of indicators in acid-base chemistry?

Back

Indicators change color to show whether a solution is acidic or basic.