MEDIUM
Lower Secondary Stage 7
IMPORTANT
Earn 100

Add ticks to the table to show whether a substance is acidic, alkaline, or neutral. The first row has been done for you.

  Acidic Alkaline Neutral
Lemon juice      
Toothpaste      
Distilled water      
Vinegar      

 

Important Questions on Acids and Alkalis

MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Workbook>Chapter 7 - Acids and Alkalis>Exercise 1>Q 2

Which hazard symbol would you find on a bottle of hydrochloric acid?

Tick one box

Question Image

 

MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Workbook>Chapter 7 - Acids and Alkalis>Exercise 1>Q 3

Use words from the box to label the diagram of the pH scale.

Neutral, acidic, alkaline, weak, strong, pH

Question Image

 

MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Workbook>Chapter 7 - Acids and Alkalis>Exercise 1>Q 4

Mia and Lily want to make an indicator from red cabbage plant using the following method. 
Step 1: Extract the dye from the cabbage leaf by mixing it in water and heating 
Step 2: Separate the dye from the remaining unwanted cabbage 
They gather together the following equipment:
Question Image

State which pieces of equipment the girls need to use to carry out step 2.

EASY
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Workbook>Chapter 7 - Acids and Alkalis>Exercise 1>Q 5

Complete the table:

Indicator Acid colour Alkali colour
Litmus red ____
Phenolphthalein ____ pink

 

MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Workbook>Chapter 7 - Acids and Alkalis>Exercise 1>Q 7
Heather plants grow best in acidic soils but other plants such as clematis prefer alkali soils. Describe how you would decide which soil sample, A or B, was suitable for growing heathers.
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Workbook>Chapter 7 - Acids and Alkalis>Exercise 1>Q 8
Explain why universal indicator paper goes dark green when toothpaste is added but orange when lemon juice is added. 
MEDIUM
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Workbook>Chapter 7 - Acids and Alkalis>Exercise 1>Q 9
Explain why universal indicator is more useful than other indicators such as litmus or methyl orange. 
EASY
Lower Secondary Stage 7
IMPORTANT
Cambridge Lower Secondary Science Stage 7 : Workbook>Chapter 7 - Acids and Alkalis>Exercise 2>Q 2
Name the salt produced when hydrochloric acid reacts with sodium hydroxide.