Science Class 7th Test Paper From Acids, Bases And Salts-1

M.M: 39 marks                                                  Dated: 16/06/2011

Time:  45 minutes

Q 1: Write True or False for the following plus write the correct answer for the false statements:         (1 mark each x 10 = 10 marks)

  i.  The word acid comes from the latin word “acere” which means bad - _________.

 ii.  Substances which are bitter in taste and feel soapy on touching are called salts - _________.

 iii.  Acids turn red litmus blue - ____________.

 iv. Neutral solutions are more acidic and less basic - ___________.

  v.  Sodium hydroxide turns red litmus to blue - _________.

  vi. The symbol for sodium is S - ________.

  vii. The symbol for potassium is K - _________.

 viii. The sting of an ant contains an acid called acetic acid - _________.

 ix. The formula for sodium hydroxide is NaOH - ________.

 x. The formula for hydrochloric acid is HoCl - ________.

Q 2: Fill in the blanks                                                       (1 mark each x 16 = 16 marks)

i.   The formula of sodium chloride is __________.

ii.  The formula of sulphuric acid is ___________.

iii. Acid + Base -------------> __________ + Water.

iv. Name of one common antacid is _________________ (more than one word may come).

v.  The formula of water is ____________.

vi. The formula of nitric acid is _____________.

vii. In case of ___________ substances, when one drop of their solution is put on either blue litmus or red litmus paper, there is no change in the colour of litmus paper.

viii. ______________ turns red litmus to blue.

ix. A base which is soluble in water is called an __________.

x.  ________ acid is used in making storage batteries for cars, buses, trucks, inverters.

xi.   _________ acid is used in fizzy soft drinks and soda water.

xii.  ________ acid is present in curd and in sour milk.

xiii. __________ acid is present in tamarind, unripe grapes, and unripe mangoes.

xiv.  ___________ acid is present in spinach.

xv.   _______ acids are the naturally occurring acids which are found in various types of plants and animals.

xvi.  ___________ turn blue litmus to red.
 

Q 3: Name one natural and one synthetic indicator.            (1 mark)

Q 4: Write names of two neutral substances.                       (1 mark)

Q 5: Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.                       (2 marks)

Q 6: What is meant by acid rain? How is acid rain caused? What two damages are caused by acid rain?                                (3 marks)

Q 7: Name two materials which should be added to acidic soil to reduce the acidity. Give reason.                                          (3 marks)

Q 8: What are three types of salts? Give one example of each type of salt.            (3 marks)