Indicators

Litmus paper is an indicator which turns red for alkalis.

• True

• false

Alkalis will turn litmus paper __________, while acids will turn litmus paper __________.

• blue.....red

• red.....blue

• pink.........colourless

• colourless..........pink

An indicator will ______________ when it is in contact with an acid or alkali

• Bubble

• Form a new substance

• Change color

• Stay the same color

What is a substance that is one color in an acid and another color in a base? 

• Oxidizer
• Indicator

What color is litmus paper in the presence of an acid?

• Red

• Blue

The pH of a strong acid would be:

• 1-2
• 5-6
• 8-9
• 12-13

The pH of a strong base would be:

• 1-2
• 5-6
• 8-9
• 13-14

The pH of a weak base would be:

• 1-2
• 5-6
• 8-9
• 12-13

The pH of a weak acid would be:

• 1-2
• 5-6
• 8-9
• 12-13

Examine the results (color change) of the Universal Indicator paper shown in the picture. What type of substance was tested?

• an acid

• an alkali

• a neutral substance

• none of the above