Q1. What is the pH of gastric juice, which is released during digestion?
Q2. A student has four samples A, B, C, D containing dil. HCI, aqueous KCI, dil. NaOH and distilled water respectively. Which two samples would show an equal value of pH?
Q3. How does a strong acid differ from a concentrated acid?
Q4. Name three chemicals in which common salt used as the raw material.
Q5. Which gas would be evolved, if sodium bicarbonate is treated with tartaric acid?
Q6. Name two crystalline substances which do not contain water of crystallisation.
Q7. Name the acid present in ant sting.
Q8. Which gas is usually liberated when an acid reacts with a metal?
Q9. Why does tooth decay start when the pH of mouth is lower than 5.5?
Q10. Name a salt which does not contain water of crystallisation.
Q11. Why is tartaric acid added into baking soda to get baking powder?
Q12. How does the concentration of H3O+ ions get affected, when a solution of an acid is diluted?
Q13. Why does dry HCI not change the colour of dry litmus?
Q14. What happens when nitric acid is added to an eggshell?
Directions (Q. Nos. 15-19) In the following questions a statement of Assertion is followed by a statement of Reason. Mark the correct choice as
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion. ·
(b) If both Assertion and Reason are true but Reason is not the correct -explanation of Assertion.
(c) If Assertion is true but Reason is false.
(d) If Reason is true but Assertion is false.
(e). If both Assertion and Reason are false.
Q15. Assertion: Acetic acid does not act as an acid in benzene solution.
Reason: Benzene is non-polar.
Q16. Assertion: Calcium oxide is a base but not an alkali.
Reason: Calcium oxide is insoluble in water.
Q17. Assertion: There is no change in the colour of litmus paper when brought in contact with distilled water.
Reason: Litmus Paper is used to find whether an solution is Acidic or Basic.
Q18. Assertion: When bleaching power is left in the open, its colour changes from blue to white.
Reason: The change in colour as oxygen breaks away from the compound.
Q19. Assertion: Sodium and Potassium is kept inside kerosene.
Reason: Sodium does not react with organic solvents like kerosene.
Q20. What is the common name of CaOCl2 ?
(a) Bleaching powder
(b) Baking soda
(c) Washing soda
(d) Lime water
Q21. Which one will turn red litmus blue?
(b) Lemon juice
(c) Soft drinks
(d) Baking soda solution
Q22. Among sulphurous acid and sulphuric acid, which is stronger?
(a) Sulphurous acid is stronger than Sulphuric Acid
(b) Sulphuric Acid is stronger than Sulphurous acid.
(c ) Sulphuric Acid and Sulphurous acid are equal in strength.
(d) Dilute Sulphuric Acid is stronger than dilute Sulphurous acid.