Q3. Which of the following is not a physical change?
Q4. Which of the following is/are true when milk changes into curd?
Q5. Which of the following does not involve a chemical reaction?
Q6. We balance the chemical equations so that they obey the:
Q7. Find the stoichiometric coefficients for the given chemical equation. aAl + bO₂ → cAl₂O₃
Q8. Find the stoichiometric coefficients for the given chemical equation. aH₂S + bO₂ → cH₂O + dSO₂
Q9. Find the stoichiometric coefficients for the given chemical equation. aNa₂SO₄ + bBaCl₂ → cBaSO₄ + dNaCl
Q10. Which of the following is/are an endothermic process(es)?
Q11. Which among the following is not an exothermic reaction?
Q12. Identify the value of variables in the chemical equation. aCa(OH)₂(aq) + CO₂(b) → CaCO₃(c) + dH₂O(l)
Q13. Which of the following are combination reactions?
Q14. Match the following:
Q15. Which among the following statement(s) is(are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to:
Q16. Identify X, Y, Z and W from the given options.
Q17. Which of the following is correct for the products formed in the electrolysis of water?
Q18. Assertion (A): The blue-green colour of the solution of copper chloride changes to colourless when lead metal is put into the solution. Reason (R): Lead is more reactive than copper and it displaces it to form lead chloride.
Q19. Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid?
Q20. In a double displacement reaction such as the reaction between sodium sulphate solution and barium chloride solution:
Q21. Which among the following is(are) double displacement reaction(s)?
Q22. A chemical reaction between aqueous solution of silver nitrate and sodium chloride produces:
Q23. Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
Q24. Which among the following when formed as a precipitate will not be white in colour?
Q25. On rusting iron forms a flaky layer over it which is ______ in colour.
Q26. Copper : Patina : Tamishing :: Silver : 'X' : 'Y' Identify 'X' and 'Y' by understanding the analogy in the same order between copper, patina and tamishing.
Q27. The following reaction is an example of a: 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g)
Q28. Which of the following statements about the given reaction are correct? 3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g)
Q29. Identify the oxidising agent (oxidant) in the following reactions. Pb₃O₄ + 8HCl → 3PbCl₂ + Cl₂ + 4H₂O