Acids Bases and Salts - Worksheets

 CBSE Worksheet-01

Class – VII Science (Acids, Bases and Salts)

  1. Which one is an organic acid?
    (a) Sulphuric acid (b) Hydrochloric acid (c) Nitric acid (d) Lactic acid
  2. Acid turns blue litmus
    (a) Red (b) Orange (c) Pink (d) Green
  3. Which of the following is a strong acid?
    (a) Citric acid (b) Acetic acid (c) Malic acid (d) Sulphuric acid
  4. Which gas is released when acid reacts with metals?
    (a) Hydrogen (b) Oxygen (c) Nitrogen (d) Carbon dioxide
  5. Match the following
    Column AColumn B
    a. Hydrochloric acidi. Natural indicator
    b. Carbonic acidii. Turns red in acid
    c. Sodium hydroxideiii. Strong acid
    d. Turmericiv. Organic acid
    e. Blue litmusv. Strong base
  6. Fill in the blanks
    1. When acid and base react together a new compound called _______ is formed.
    2. All acids contain _______.
    3. Metal on heating or burning produce _______ of metals.
    4. Turmeric is a _______ indicator.
    5. Minerals acids are obtained from _______.
  7. What are indicators? Give two examples.
  8. What is neutralization reaction?
  9. What are alkalies? Give two examples.
  10. Classify the following as organic and mineral acids?
    Hydrochloric acid, Citric acid, Malic acid, Nitric acid, Oxalic acid, Sulphuric acid.

CBSE Worksheet-01
Class – VII Science (Acids, Bases and Salts)
Answer key

  1. d
  2. a
  3. d
  4. a
  5. (a) – (iii), (b) – (iv), (c) – (v), (d) – (i), (e) – (ii).
  6. (a) Salt (b) hydrogen (c) oxide (d) natural (e) minerals.
  7. Indicators are substances that are used to test whether a substance is acidic or basic or neutral in nature. They change their colour when added to a solution containing an acidic or a basic substance.Indicators are of two types - natural and artificial.
    Natural Indicator: Turmeric , Litmus
    Artificial Indicators: Phenolphthalein
  8. The reaction between an acid and a base two form salt and water is called neutralization reaction.
    NaOH + HCl -> NaCl + H2O.
  9. Metal oxides are basic in nature. Those bases that dissolve in water are called alkalies. Sodium hydroxide and Potassium hydroxide are two common example of alkalies.
  10.  
    Organic acidsMineral acids
    Citric acidHydrochloric acid
    Malic acidNitric acid
    Oxalic acid.Hydrochloric acid