Caelum High School Chemistry Past Paper 2022-23 PDF

## Caelum High School Term II Examination 2022-23 Chemistry **Class:** IX **Time:** 2 hrs **Marks:** 80 **Roll No:** **Instructions:** * Answers to this Paper must be written on the paper provided separately. * You will not be allowed to write during the first 15 minutes. This time is to be spent...

## Caelum High School Term II Examination 2022-23 Chemistry **Class:** IX **Time:** 2 hrs **Marks:** 80 **Roll No:** **Instructions:** * Answers to this Paper must be written on the paper provided separately. * You will not be allowed to write during the first 15 minutes. This time is to be spent in reading the Question Paper. * The time given at the head of this paper is the time allowed for writing the answers. * Section I is compulsory. Attempt any four questions from Section II. * Intended marks for question or parts of questions are given in brackets []. ### Section A (40 Marks) #### Attempt all questions from this Section **A. Choose the correct answer from the options given below:** **(15)** 1. **A salt which leaves yellow residue on heating** * a. Copper nitrate * b. Copper carbonate * c. Lead nitrate * d. Ammonium dichromate 2. **The valency of nitrogen in nitrogen dioxide is** * a. 1 * b. 2 * c. 3 * d. 4 3. **Volume temperature relationship is given by** * a. Dalton * b. Boyle * c. Charles * d. Lavoisier 4. **An alkaline earth metal of the third period is:** * a. Ba * b. Ca * c. Mg * d. Be 5. **The metal oxide which reacts with both acid and alkali** * a. AgO * b. ZnO * c. CuO * d. CaO 6. **Separation of hydrogen from carbon dioxide is achieved by passing the mixture through:** * a. Ammoniacal cuprous chloride * b. Potassium hydroxide solution * c. Ferric oxide solution * d. Sodium chloride solution 7. **The molecule which contains a triple covalent bond is:** * a. Ammonia * b. Methane * c. Water * d. Nitrogen 8. **Which of the following is not true about property trends across a period?** * a. Elements become less metallic in nature * b. The number of valence electrons increases * c. The atoms lose their electrons more easily * d. The oxides become more acidic. 9. **The absolute temperature value that corresponds to 27°C is** * a. 200 K * b. 300 K * c. 400 K * d. 246 K 10. **A substance that shows considerable increase in the solubility with rise in temperature:** * a. Sodium nitrate * b. Sodium chloride * c. Calcium sulphate * d. Calcium hydroxide 11. **The Empirical formula of hydrogen peroxide is** * a. HO * b. OH * c. H₂O * d. HO₂ 12. **Identify the most reactive element** * a. Hydrogen * b. Zinc * c. Sodium * d. Argon 13. **The cation that imparts golden yellow colour to the flame** * a. Na⁺ * b. K⁺ * c. Cu²⁺ * d. Al³⁺ 14. **Ozone depletion is mainly caused by** * a. UV radiations of sun. * b. Excessive use of detergents. * c. Burning coal and wood. * d. Use of CFC compounds 15. **A phenomenon where a compound absorbs moisture from the atmosphere when it is exposed to it but not enough to form a solution** * a. Hygroscopy * b. Drying * c. Efflorescence * d. Deliquescency. **B. Give the appropriate term:** **(5)** 1. The substance that can remove hydrogen and oxygen atoms in the ratio of 2:1 (in the form of water) from the compounds. 2. Bond formed between metals and non-metals. 3. A substance that influences the rate of a chemical reaction by improving the efficiency of the catalyst. 4. A chemical process which involves removal of oxygen or addition of hydrogen. 5. The reaction between an acid and a base that forms salt and water only. **C. An atom of an element X has 1 electron in the N shell.** **(5)** 1. State its electronic configuration. 2. Is it a metal or non-metal? 3. State the number of protons in X. 4. Write the formula of its chloride. 5. Where is this element placed in the periodic table? **D. State one relevant observation for:** **(5)** 1. Zinc carbonate is heated. 2. Few pieces of iron are dropped into a blue coloured copper sulphate solution. 3. Hydrated copper sulphate is heated in a test tube. 4. Dilute sulphuric acid reacts with zinc carbonate. 5. Silver nitrate solution is mixed with hydrochloric acid. **E. Give reasons:** **(5)** 1. Table salt turns moist on exposure to air. 2. Calcium oxide is an ionic bond. 3. Group I metals are known as alkali metals. 4. Nitric acid, even in the dilute form, is not used in preparation of hydrogen. 5. It is necessary to specify the pressure and temperature of a gas while stating its volume. ### Section B: (40 Marks) #### Attempt any four questions from this Section. **III.** **A.** **(3)** 1. State a difference between temporary hard water and permanent hard water. 2. Write the equation: Soda ash is added to permanent hard water. 3. State one advantage of hard water. **B. Draw the isotopes of Hydrogen** **(3)** **C. Complete the following equations and balance it:** **(2)** 1. Decomposition of potassium nitrate 2. Formation of ammonium chloride **D.** 120 cm³ of a gas is taken at 27.3 K. The temperature is then raised at 0°C. What is the new volume of the gas? The pressure is kept constant. **IV.** **A.** An element X has 2 electrons in its M shell, it forms a bond with an element Y which has 7 electrons in the third orbit. **(2)** 1. Write the formula of the compound formed. **(1)** 2. Show by orbital diagram the formation of a compound between X and Y. **(2)** **B. Arrange the following as per the instructions given in the brackets:** **(2)** 1. Cl, Na, Al (Increasing atomic size) 2. Cl, F, I (Decreasing reactivity) **C. State the type of bond in each of the following** **(3)** 1. Oxygen 2. Nitrogen 3. Ethane **D.** **(2)** 1. Name any two green house gases. 2. State one effect of green house gases on the atmosphere. **V.** **A.** Answer the following question based on the Laboratory method of preparation of hydrogen: **(3)** 1. Write the equation. 2. How is the gas collected? 3. Name the drying agent. **B. Answer the following questions based on Mendeleev's periodic table.** **(3)** 1. Name an element whose properties were predicted. 2. Name an element whose atomic weight was corrected. 3. How many elements were known at that time? **VI.** **A. Calculate the percentage of nitrogen in urea NH₂CONH₂ [C=12, H=1, O=16, N=14]** **(3)** **B. Calculate the valency:** **(3)** 1. An element having 8 electrons in the M shell. 2. Carbon in methane 3. An element having 2 electrons in the N shell. **C. Explain the following** **(4)** 1. Potassium is stored under kerosene oil. 2. Anhydrous iron [III] chloride turns to a solution when exposed to air. 3. A solution copper sulphate cannot be stored in a pot made of iron. 4. Non - metals are good oxidising agents. **VII.** **A. Differentiate between the following by a chemical test:** **(3)** 1. Calcium chloride and Potassium chloride by a Flame test 2. Sodium sulphide and sodium sulphite by adding dilute sulphuric acid. 3. Chlorine and Hydrogen chloride by litmus paper. **B.** One litre of a gas at 10°C is heated till both its volume and pressure are tripled. Find the new temperature. **(3)** **C.** State the type of the reactions each of the following represent. **(2)** 1. Cu(NO₃)₂ + 2CuO + 4 NO₂ + O₂ 2. Pb(OH)₂ + 2HNO₃ → Pb(NO₃)₂ + 2H₂O **D. State the:** **(2)** 1. Effect of cooling a saturated solution. 2. Effect of heating a saturated solution. **VIII.** **A. Answer the following questions based on the metal activity series:** **(3)** 1. Highly reactive element 2. Least active metal 3. A metal which cannot displace hydrogen from dilute acids. **B. State the conditions required for the following reactions:** **(3)** 1. Formation of the ammonia. 2. Decomposition of hydrogen peroxide. 3. Decomposition of water. **C. Two elements 'P' and 'Q' belong to the same period of the modern periodic table and in Group 1 and Group 17 respectively. Compare the characteristics in tabular form.** **(2)** 1. Valence electrons. 2. Types of ions. **D. State the value of pressure in** **(2)** 1. atm 2. mm Hg