Unit Test: Acid, Bases & Salts | Science Class 10 PDF Download

Time: 1 hour

M.M. 30

Attempt all questions.

• Question numbers 1 to 5 carry 1 mark each.
• Question numbers 6 to 8 carry 2 marks each.
• Question numbers  9 to 11 carry 3 marks each.
• Question number 12 & 13 carry 5 marks each

Q1: Which of the following substances is an acid?  (1 Mark)
(a) NaOH
(b) HCl
(c) NH₃
(d) KOH

Q2: The pH value of a neutral solution is:  (1 Mark)
(a) 0
(b) 7
(c) 14
(d) 10

Q3: Which of the following is a natural indicator?  (1 Mark)
(a) Phenolphthalein
(b) Litmus
(c) Methyl orange
(d) Universal indicator

Q4: Write the chemical equation for the reaction between an acid and a metal.  (1 Mark)

Q5: Name one common substance that can be used to neutralize the excessive acidity in the stomach.  (1 Mark)

Q6: Identify the salt and the acid used in the reaction to prepare the salt: Calcium chloride. Write the chemical equation for the reaction. (2 marks)

Q7: A student added a few drops of phenolphthalein to a colourless solution taken in a test tube. The solution turned pink. Predict whether the solution is acidic or basic, and write a balanced chemical equation for the reaction that might have occurred. (2 marks)

Q8: What happens when an antacid is taken after overeating? How does it provide relief? (2 marks)

Q9: Explain the process of neutralization. Why is the reaction mixture not acidic or basic at the end point of a neutralization reaction? (3 marks)

Q10: Why should we not touch the chemicals used for tasting or testing their reaction for acidity or basicity? Write the general precautions one should follow while performing a chemistry experiment in the laboratory.  (3 marks)

Q11: How can you distinguish between baking powder and washing soda by heating? Write the chemical reactions involved. (3 marks)

Q12: Explain the action of the following:
(i) Lime water on blue litmus paper
(ii) Dilute hydrochloric acid on a piece of blue litmus paper (5 marks)

Q13: Describe the process of the formation of a curd from milk. Write the chemical equation for the reaction that takes place during the curdling of milk. (5 marks)