Review Unit 7 Material Changes

Which of the following descriptions about nitric acid is incorrect?

• It turns blue litmus paper to red

• The blue litmus paper remains blue

• The red litmus paper remains red

• The pH value is below 7

This corrosive substance is a strong alkali.

• beetroot

• cabbage

• nitric acid

• sodium hydroxide

If a Universal Indicator goes green, the solution must be ....

• strong acid

• acid

• alkali

• neutral

If a Universal Indicator goes red, the solution must be ....

• strong acid

• strong alkali

• alkali

• neutral

Pure water is neutral. Which one of these pH values is neutral?

• pH 1

• pH 5

• pH 7

• pH 10

Ammonia solution is a weak alkali and it turns a Universal Indicator into....

• red

• yellow

• blue

• purple

Joanne is having a stomachache due to acidity problem. Which of the following can neutralize the acidity and help her feel better?

• Citric acid

• Lemon juice

• Mango juice

• Magnesium hydroxide

There are several methods that farmers usually used to maintain the pH of soil at an acceptable level for the crops to be grown. One of those is adding ___________ to acidic soil.

• salt

• sugar

• lime

• vinegar

This symbol indicates....

• harmful substance

• toxic substance

• flammable substance

• corrosive substance

This symbol indicates....

• harmful substance

• toxic substance

• flammable substance

• corrosive substance