Q1. Which of the following is an example of a precipitate forming reaction?A CaCO3(s) → CaO(s) + CO2(g) B NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l) C Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g) D Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) View full solution →
Q2. Which type of reaction is characterized by the exchange of ions between two compounds?A Double displacement reaction B Decomposition reaction C Combination reaction D Displacement reaction View full solution →
Q3. Which type of reaction involves the breakdown of a single compound into two or more simpler substances?A Double displacement reaction B Displacement reaction C Decomposition reaction D Combination reaction View full solution →
Q4. Which of the following substances will show a color change when heated strongly, and what is the color change?A Lead nitrate; from white to yellow-brown residue and reddish-brown gas B Copper sulphate; from blue to green C Zinc oxide; from white to grey D Sodium chloride; from white to yellow View full solution →
Q5. In the reaction: FeSO4(aq) + Cu(s) → No reaction. Why does this happen?A Both are equally reactive. B Copper is more reactive than iron. C It is a decomposition reaction. D Iron is more reactive than copper. View full solution →
Q6. In the decomposition of lead nitrate powder, what is the color of the gas evolved and the residue left?A Brown gas, black residue B Colorless gas, black residue C Colorless gas, yellow residue D Brown gas, yellow residue View full solution →
Q7. Which of the following is a balanced equation?A H2 + O2 → H2O B 2H2 + O2 → 2H2O C 2H2 + O2 → H2O D H2 + 2O2 → 2H2O View full solution →
Q8. A solution of potassium bromide is mixed with a solution of lead nitrate. What will be the observation, and what type of reaction is it?A Solution turns red; Displacement reaction B Evolution of a gas; Decomposition reaction C Formation of a white precipitate; Combination reaction D Formation of a yellow precipitate; Double displacement reaction View full solution →
Q9. Which type of reaction is the thermite reaction (Fe2O3 + 2Al → Al2O3 + 2Fe)?A Combination reaction B Double displacement reaction C Decomposition reaction D Displacement reaction View full solution →
Q10. Which of the following compounds is a strong oxidizing agent often used in redox titrations?A HCl B KMnO4 C Na2CO3 D BaSO4 View full solution →
Q11. Assertion (A): Calcium carbonate decomposes into calcium oxide and carbon dioxide when heated. Reason (R): The decomposition reaction requires energy in the form of heat.A Both A and R are true and R is the correct explanation of A. B A is true but R is false. C Both A and R are true but R is not the correct explanation of A. D A is false but R is true. View full solution →
Q12. A white solid on heating produces a gas that turns limewater milky and a residue that is yellow when hot but white when cold. Identify the white solid.A Zinc carbonate B Lead nitrate C Calcium carbonate D Sodium carbonate View full solution →
Q13. Balance the equation: C6H12O6 + O2 → CO2 + H2O. What is the coefficient of O2?A 12 B 18 C 6 D 1 View full solution →
Q14. If a student heats a blue crystalline solid, it turns white, and water droplets are observed on the cooler parts of the test tube. What is the blue crystalline solid?A Zinc sulphate B Hydrated copper sulphate C Anhydrous copper sulphate D Copper carbonate View full solution →
Q15. What type of reaction occurs when an acid reacts with a base?A Combination reaction B Precipitation reaction C Neutralization reaction D Decomposition reaction View full solution →
Q16. A student performs an experiment where he adds dilute sulphuric acid to barium chloride solution. What visual change will he observe?A No visible change occurs. B The solution turns green. C A black precipitate forms. D A white precipitate forms. View full solution →
Q17. Which of the following reactions is used for the preparation of oxygen in the laboratory?A 2NaNO3(s) → 2NaNO2(s) + O2(g) B 2H2O(l) → 2H2(g) + O2(g) (electrolysis) C 2KClO3(s) → 2KCl(s) + 3O2(g) (with MnO2 catalyst) D 2Mg(s) + O2(g) → 2MgO(s) View full solution →
Q18. Which of the following is an exothermic process?A Respiration B Photosynthesis C Evaporation of water D Melting of ice View full solution →
Q19. Consider the following reaction: A + B → C + Heat. What can be inferred about this reaction?A It is an exothermic reaction. B It is an endothermic reaction. C The activation energy is very high. D It is a decomposition reaction. View full solution →
Q20. What happens when an iron nail is dipped in a copper sulphate solution?A The solution turns colourless, and copper coating appears on the nail. B No reaction occurs. C The solution turns green, and copper coating appears on the nail. D The solution turns blue, and iron coating appears on the nail. View full solution →