GR-7 Acid, Bases and Salts

A base used in baking bread is:

• NaHCO₃

  
  

• CaCO₃

• NH₄OH

  
  

• None of the above

Choose the incorrect statement about acid.

(i) Acids have a sour taste.(ii) Acids turn blue litmus red.(iii) Acids have a soapy feel.(iv) Acids are non-corrosive in nature.

• (i) and (iv)

• (ii) and (iii)

• (i) and (ii)

• (iii) and (iv)

A student understands that litmus solution has purple colour in distilled water. What colour is

likely to be observed when it is placed in an acidic solution?

• Blue

• Green

• Red

• Purple

Which of these mixtures represents a neutralization reaction?

• Acid +Acid

• Acid +Base

• Acid + Water

• Base +Water

A base contained in calamine solution which neutralises the acidic liquid of the ant is:

• Mg(OH)₂

  
  

• ZnCO₃

• HNO₃

• NaHCO₃

When Vedika washed a stain of vegetable curry on her suit with a cloth washing bar then it turned brownish-red, then it shows that the:

• Stain was of turmeric and the cloth washing bar was acidic.

• Stain was of ice-cream and the cloth washing bar was acidic.

• Stain was of turmeric and the cloth washing bar was basic.

• Stain was of yellow paint and the cloth washing bar was acidic.

Which of the following is a neutral substance?

• Distilled water

• Common salt

• Sugar

• All the above

Sodium Chloride will turn:

• Turmeric brownish-red

• China rose green

• Litmus blue to red

• None of these

Properties of an acid is due to the presence of:

• Ammonium ions

• Oxide ions

• Hydrogen ions

• Hydride ions

Acid rain is caused due to the excess of:

• Carbon dioxide

• Sulphur dioxide

• Nitrogen dioxide

• All the above