Q1. Suppose you are a farmer living at a place having black soil. If the climate of your region is warm and you want to grow fiber yielding plants in your fields, then which of the following would you prefer?
Q2. Aqueous solution of which of the following oxides will change the color of blue litmus to red?
(a) Copper oxide
(b) Iron oxide
(c) Magnesium oxide
(d) Sulphur dioxide
Q3. A boy has a thick paste of turmeric. On adding this past to hydrochloric acid and aqueous solution of sodium hydroxide separately, what color(s) would he observe?
(a) Pink in hydrochloric acid and blue in sodium hydroxide
(b) Blue in hydrochloric acid and red in sodium hydroxide
(c) Yellow in both cases
(d) Yellow in hydrochloric acid and red in sodium hydroxide
Q4. A student puts a drop of dilute solution of sodium hydroxide first on a blue litmus paper and then on a red litmus paper. He would observe that
(a) The blue litmus paper turns red and the red litmus paper turns blue
(b) There is no change in the blue litmus paper and the red litmus paper turns blue
(c) The is no change in the red litmus paper and the blue litmus paper turns red
(d) The blue litmus paper turns colorless and there is no change in the red litmus paper
Q5. You have phenolphthalein solution in three test tubes A, B and C. On putting 2-3 drops of dilute hydrochloric acid in A, a solution of sodium hydroxide in B and distilled water in C, if you immediately observe the color of the solution in each test tube, then you will find that the solution in test tube.
(a) A is colorless, in B pink and in C colorless
(b) A is pink, in B pale green and in C colorless
(c) A is colorless, in B colorless and in C pink
(d) A is pale green, in B pink and in C pink
Q6. Tartaric acid is found in
C. Unripe mangoes
(a) A and B
(b) B and C
(c) C and D
(d) A and C
Q7. The common characteristic properties of plastics are
(a) Durable, good conductor of electricity, non-reactive
(b) Durable, good conductor of heat, non-reactive
(c) Good conductor of heat, light in weight, good conductor of electricity
(d) Durable, light in weight, non-reactive
Q8. You have two test tubes A and B. test tube A contains paste of turmeric, whereas test tube B contains aqueous solution of phenolphthalein. On adding a few drops of dilute hydrochloric acid to these test tubes the contents of
(a) A and B both would appear red
(b) A would appear red while those of B would remain colorless
(c) A would remain yellow while those of B would appear pink
(d) A would remain yellow while those of B would remain colorless
Q9. Each cell in our body contains DNA. We also have proteins and fats in our body. What is common among DNA, proteins and fats?
(a) All contains acids
(b) All are inorganic
(c) All are salts
(d) All contain bases
Q10. Identify the incorrect statement.
A. Acids are sour in tests whereas bases are bitter in taste and soapy to touch.
B. Acids turn blue litmus red and bases turn red litmus blue.
C. Solutions of substances that show different colors in acidic, basic and neutral solutions are called indicators.
D. An acid and a base neutralize each other to form a salt and a salt is always neutral.
(a) A, D
(c) B, C