1. The first scientific theory of an atom was proposed by………….
2. Assertion: The standard unit for expressing mass of atom is amu. Reason: Atomic mass unit is one-twelth of the mass of a C-12 atom
3. Assertion: The volume occupied by 44 g of CO2 is 22.4 L Reason: The volume occupied by one mole of any gas is 22.4 L
4. The average atomic mass of Beryllium is 9.012 because of the presence of isotopes.
5. For the reaction A + 2B → C, 5 moles of A and 8 moles of B will produce…………
6. Out of the following the largest number of atoms are contained in ……………
7. The percentage of nitrogen in urea is about……………….
8. The mass percentage of hydrogen in ethane (C2H6) is…………….
9. The volume occupied by 3 moles of HCl gas at STP is……….
10. If 1.5 moles of oxygen combine with Al to form Al2O3, the mass of Al in g (atomic mass of Al = 27) used in the reaction is…..
11. Assertion: The nature of bond in HF molecule is ionic. Reason: The electronegativity difference between H and F is 1.9.
12. The ore forming elements, chalcogens are present in ……… group of the modern periodic table.
13. The covalent radii of Hydrogen, if the distance between the Hydrogen nuclei of the molecule is 0.74 Å is…………
14. In the third period, the first ionization potential is of the order……………
15. Electrolyte used in Hall’s process ______.
16. Three elements A, B and C are having the electronic configuration Is2 2s1, Is2 2s2 and Is2 2s2 2p1 respectively. Which element will have the lowest ionization energy?
17. The highly metallic element will have the configuration of………………
18. Assertion: Zinc blende is concentrated by Froth floatation process. Reason: Zinc blende is a sulphide ore.
19. Assertion: In thermite welding, aluminium powder and Fe2O3 are used. Reason: Aluminium powder is a strong reducing agent.
20. Assertion: To design the body of an aircraft, aluminium alloys are used. Reason: Aluminium becomes passive when it is treated with dil or con.HNO3.
21. A solution in which no more solute can be dissolved in a definite amount of solvent at a given temperature is called ______.
22. Solubility of NaCl in 100 ml water is 36 g. If 25 g of salt is dissolved in 100 ml of water how much more salt is required for saturation………………
23. When Silica gel is kept open, it absorbs moisture from the air, because it is hygroscopic in nature.
24. Formalin is an aqueous solution of………….
25. The effect of pressure on the solubility of a gas in liquids is given by…………
26. A supersaturated solution is one that contains more solute than the saturated solution at a given temperature. E.g. 40 g of sodium chloride in 100 g of water at 25°C.
27. The solubility of a gas in a liquid is inversely proportional to the pressure of the gas at a definite temperature.
28. The molecular formula of Epsom salt is ______.
29. Tin amalgam is an example of ……… solution.
30. Which one of the following is an example of an aqueous solution?
31. A reaction between carbon and oxygen is represented by C(s) + O2(g) → CO2(g) + Heat. In which of the type(s), the above reaction can be classified? (i) Combination Reaction (ii) Combustion Reaction (iii) Decomposition Reaction (iv) Irreversible Reaction
32. The chemical equation Na2SO4(aq)+BaCl2(aq)→BaSO4(s)↓+2NaCl(aq) represents which of the following types of reaction?
33. Which of the following statements are correct about a chemical equilibrium? (i) It is dynamic in nature (ii) The rate of the forward and backward reactions are equal at equilibrium (iii) Irreversible reactions do not attain chemical equilibrium (iv) The concentration of reactants and products may be different.
34. A single displacement reaction is represented by X(s)+2HCl(aq)→XCl2(aq)+H2(g). the following(s) could be X? (i) Zn (ii) Ag (iii) Cu (iv) Mg. Choose the best pair.
35. Powdered CaCO3 reacts more rapidly than flaky CaCO3 because of ………….
36. KI and Pb(NO3)2 solutions are mixed to give a precipitate. What is the colour of the precipitate?
37. Formation of calcium silicate from silica and calcium oxide is a combination reaction.
38. The Metathesis reaction among the following is………..
39. The decomposition of AgBr into grey coloured silver metal is an example of ……… reaction.
40. As the decomposition is caused by light, this kind of reaction is called ______.
41. Assertion: Detergents are more effective cleansing agents than soaps in hard water. Reason: Calcium and magnesium salts of detergents are water soluble.
42. Assertion: Alkanes are saturated hydrocrabons. Reason: Hydrocarbons consits of covalnet bonds.
43. The IUPAC name of an organic compound is Pentan-2-one. The secondary suffix is………
44. Molasses is fortified with ………… to increase the nitrogen content.
45. Assertion: Alkynes decolourise bromine water. Reason: Alkynes are unsaturated compounds.
46. Assertion: Denaturation of ethanol makes it unfit for drinking purpose. Reason: Ethanol is mixed with Pyridine for denaturation.
47. Assertion: Organic compounds contains covalent bond. Reason: Organic compounds have low melting and boiling points.
48. Assertion: Due to catenation a large number of carbon compounds are formed. Reason: Carbon compounds show the property of allotropy.
49. Pick out the unsaturated compound from the following ______.
50. Organic compounds are _____ in nature.