Topic wise Mole Concept Questions, Exercises of Chemistry

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Topic-WiSE

Question

Bank for

Chapter :

Basic

Concepts of

Chemistry

Set 1

Topics Covered: Application of chemistry ,Matter,Classification of matter,Mixture (meaning ,examples & types) ,Atoms,Molecules,Elements Compounds,Subatomic particles(all 3 in detail-their, masses, charge, sign, representation,formula), Specific charge,Symbol of an element,Mass number,Atomic number,Atomicity,Ions(meaning ,examples & types),number of subatomic particles in an atom,number of subatomic particles in an iron and formula to obtain them. Q1. Which branch of chemistry deals with the study of carbon compounds except oxides of carbon and carbonates? A. Inorganic B. Organic C. Physical D. Analytical Q2. Which of the following is not a physical property of matter? A. Mass B. Volume C. Reactivity D. Density Q3. Which of the following is a homogeneous mixture? A. Air B. Oil and water C. Sand and salt D. Iron fillings and sulphur Q4. Which of the following is a chemical change? A. Melting of ice B. Rusting of iron C. Boiling water D. Sublimation of iodine Q5. Which of the following is a triatomic molecule? A. H₂ B. O₃ C. N₂ D. He Q6. The charge on an electron is:

A. N = Z + A

B. N = A – Z

C. N = A/Z

D. N = Z – A

Q16. Which of the following is a cation? A. Cl⁻ B. Na⁺ C. OH⁻ D. SO ²₄ ⁻ Q17. An element has atomic number 11 and mass number 23. Its number of protons and neutrons are: A. 11, 12 B. 12, 11 C. 23, 11 D. 11, 23 Q18. Which scientist discovered the electron? A. Rutherford B. Thomson C. Goldstein D. Chadwick Q19. The number of atoms present in 1 mole of a substance is: A. 3.011 × 10²² B. 6.022 × 10²³ C. 1.602 × 10 ¹⁹⁻ D. 9.11 × 10 ³¹⁻ Q20. Which particle determines the chemical properties of an atom? A. Proton B. Neutron C. Electron D. Nucleus Q21. Identify the heterogeneous mixture: A. Air B. Brass C. Smoke D. Sugar solution Q22. Atomicity of phosphorus is: A. 2 B. 4 C. 8 D. 5 Q23. Which of the following is not a subatomic particle? A. Electron B. Proton C. Positron D. Neutron

Q24. Mass number is equal to: A. Protons only B. Protons + Electrons C. Protons + Neutrons D. Electrons + Neutrons Q25. Which of the following is not an element? A. Oxygen B. Iron C. Water D. Nitrogen Q26. Which one of the following is an example of compound? A. Air B. Brass C. Sodium chloride D. Soil Q27. The charge on a proton is: A. –1.602 × 10 ¹⁹ C⁻ B. +1.602 × 10 ¹⁹ C⁻ C. 0 C D. +9.11 × 10 ³¹ C⁻ Q28. The number of protons in Cl ⁻is: A. 16 B. 17 C. 18 D. 19 Q29. An ion having more electrons than protons is called: A. Cation B. Anion C. Isotope D. Isobar Q30. Which is correct for isotopes? A. Same Z, different A B. Same A, different Z C. Same number of neutrons D. Same mass Q31. Specific charge is defined as: A. Charge per mass B. Mass per charge C. Mass per volume D. Charge per volume Q32. Which has the lowest mass? A. Proton B. Neutron C. Electron D. Alpha particle

Q42. Which type of mixture scatters light? A. Solution B. Colloid C. Suspension D. Both b and c Q43. Who proposed the plum pudding model? A. Rutherford B. Bohr C. Thomson D. Dalton Q44. What is the formula of calculating electrons in an ion? A. e ⁻= Z + charge for cations B. e ⁻= Z – charge for cations C. e ⁻= Z – charge for anions D. e ⁻= Z + charge for anions Q45. Which of the following is a monatomic element? A. Ne B. N₂ C. O₂ D. Cl₂ Q46. The ratio of charge to mass of an electron was first measured by: A. Thomson B. Millikan C. Rutherford D. Chadwick Q47. The number of neutrons in ³⁵ ₁₇Cl is: A. 17 B. 18 C. 35 D. 52 Q48. Which of the following represents an isotope pair? A. ¹H, ²H B. ¹²C, ¹⁴N C. ¹⁶O, ¹⁶S D. ²³Na, ²⁴Mg Q49. Which of the following is not a correct match? A. e ⁻ : –1.602 × 10 ¹⁹ C⁻ B. p ⁺ : +1.602 × 10 ¹⁹ C⁻ C. n⁰ : +1.602 × 10 ¹⁹ C⁻ D. e ⁻ mass : 9.11 × 10 ³¹ kg⁻ Q50. The number of protons in ⁵⁶ ₂₆Fe³ ⁺is: A. 23 B. 26 C. 29 D. 30

Set 2

Topics Covered:

**1. Scientific notation

2. Significant figures
3. Rounding off of single digit as well as multiple digits 4.Addition/ Subtraction/ Multiplication/Division of Significant figures
4. Precision and accuracy(concept, meaning,difference)
5. International System of units (SI) ( basic physical quantities and their SI units + supplementary units) & physical properties and chemical properties(meaning, difference, examples)
6. Temperature ( meaning,temperature scales ,SI unit ,relationship between Kelvin and Celsius ,relationship between Fahrenheit and Celsius /formulas for interconversion)
7. Dalton Atomic Model ( explanation -detailed information,counterpoints) 9.Isotopes,Isobars,Isotones,Isodiapers isoelectronic,Isoelectronic, Isosters
8. Law of chemical combinations**

PART 1- (Questions 1-150)

Q1. Express 0.000567 in scientific notation. Q2. Convert 7.89 × 10⁴ into standard form. Q3. Which of these is correct scientific notation? (a) 45.6 × 10³ (b) 4.56 × 10³ (c) 0.456 × 10⁴ (d) 456 × 10² Q4. Which of the following is the correct representation of 6,500,000? (a) 6.5 × 10⁷ (b) 6.5 × 10⁶ (c) 65 × 10⁵ (d) 0.65 × 10⁷ Q5. Convert 2.34 × 10 ³ to decimal form.⁻ Q6. Convert 0.00000567 to proper scientific notation. Q7. Which number is greater? (a) 5.2 × 10 ³ (b) 4.8 × 10 ²⁻ ⁻

Q34. 4.500 × 10² has how many significant figures? Q35. Which has more significant figures? (a) 2.30 (b) 2.003 (c) Both same Q36. Identify significant figures in 3.4 × 10 ².⁻ Q37. 0.00052 has how many significant figures? Q38. 700 has how many significant figures (no decimal)? Q39. Which has 1 significant figure? (a) 0.04 (b) 40 (without decimal) (c) Both a & b Q40. Which has the least number of significant figures? (a) 2.3 × 10³ (b) 0.0023 (c) 230.0 (d)

Q41. Round 4.564 to 3 significant figures. Q42. Round 0.004562 to 2 significant figures. Q43. Round 9.995 to 3 significant figures. Q44. Multiply 2.34 (3 sig. figs.) × 1.2 (2 sig. figs.) — answer in correct sig. figs. Q45. Divide 3.45 (3 sig. figs.) by 1.5 (2 sig. figs.) — correct sig. figs. Q46. Add 2.45 + 1.2 — correct sig. figs. Q47. Subtract 5.678 – 2.4 — correct sig. figs. Q48. Round 0.00456 to 1 significant figure. Q49. Round 3.9995 to 4 significant figures. Q50. Round 123456 to 3 significant figures (scientific notation form). Q51. 2.34 × 1.56 =? (correct sig. figs.) Q52. 12.3 ÷ 0.00456 =? (correct sig. figs.) Q53. (3.45 + 2.1) × 1.2 — correct sig. figs. Q54. Round 8.765 to 2 significant figures. Q55. Round 0.0009995 to 2 significant figures. Q56. Round 9999 to 2 significant figures. Q57. Multiply 1.234 × 0.0056 — correct sig. figs. Q58. Divide 45.67 by 2.1 — correct sig. figs. Q59. Add 456.7 + 45.67 — correct sig. figs.

Q60. Round 78.99 to 3 significant figures. Q61. Which describes closeness to true value? (a) Accuracy (b) Precision Q62. Which describes closeness among repeated values? (a) Accuracy (b) Precision Q63. A measurement of 5.1 cm for an actual length of 5.0 cm is: (a) Accurate (b) Precise (c) Both Q64. Consistently getting 4.8 cm when true value is 5.0 cm shows: Q65. High accuracy but low precision means: Q66. High precision but low accuracy means: Q67. Which instrument generally has better precision? (a) Meter scale (b) Vernier caliper Q68. Which is more precise: 2.30 g or 2.3 g? Q69. Which is more accurate if true value is 50 g? (a) 49.9 g (b) 50.5 g Q70. Precision is related to: (a) Random errors (b) Systematic errors Q71. Accuracy is affected mainly by: (a) Random errors (b) Systematic errors Q72. Measuring same object repeatedly and getting same reading indicates: Q73. Accuracy improves by: (a) Reducing systematic errors (b) Reducing random errors Q74. Precision improves by: (a) Reducing systematic errors (b) Reducing random errors Q75. Which statement is true? (a) High accuracy always means high precision (b) Both can be independent Q76. Which is more precise? (a) 4.500 g (b) 4.50 g Q77. Which is more accurate if true mass = 10.00 g? (a) 9.98 g (b) 10.05 g Q78. Which affects precision more? (a) Least count of instrument (b) Zero error Q79. Which affects accuracy more? (a) Least count of instrument (b) Calibration error Q80. Consistent but wrong readings mean: (a) Accurate (b) Precise (c) Both (d) Neither Q81. SI unit of length is: Q82. SI unit of mass is: Q83. SI unit of time is: Q84. SI unit of temperature is:

Q108. Identify the chemical property: (a) colour (b) melting point (c) odour (d) ability to react with chlorine Q109. Which of the following has a unit of kg·m/s²? (a) work (b) force (c) pressure (d) energy Q110. The SI base unit for time is defined by: (a) period of pendulum (b) vibrations of cesium- 133 atom (c) Earth’s rotation (d) frequency of light Q111. Which of the following scales does NOT use absolute zero? (a) Kelvin (b) Celsius (c) Rankine (d) none Q112. Convert 0°C to Kelvin. Q113. Temperature difference of 100°C corresponds to how many Kelvin? Q114. Which of the following is correct: (a) K = °C + 273 (b) °C = K – 273 (c) °F = (9/5)°C + 32 (d) all Q115. The temperature 98.6°F in °C is approximately: (a) 37°C (b) 36°C (c) 38°C (d) 35°C Q116. Convert 0°F to Celsius. Q117. Which is larger: 10°C rise or 20°F rise? Q118. Absolute zero corresponds to: (a) −273°C (b) −459°F (c) 0 K (d) all Q119. Which formula is correct? (a) °C = (5/9)(°F – 32) (b) °F = (9/5)°C + 32 (c) K = °C + 273.15 (d) all Q120. Convert 350 K to °C. Q121. Dalton’s atomic theory proposed that: (a) atoms are indivisible (b) atoms of same element have same mass (c) atoms combine in simple whole number ratios (d) all Q122. Which statement is inconsistent with Dalton’s theory? (a) Atoms are indivisible (b) Atoms of different elements differ in mass (c) Atoms can be created or destroyed in a chemical reaction (d) Compounds are formed by combination of atoms Q123. Which discovery challenged Dalton’s indivisibility postulate? (a) electron (b) proton (c) neutron (d) nucleus Q124. Which of the following was NOT part of Dalton’s postulates? (a) Atoms cannot be subdivided (b) Atoms combine in whole number ratios (c) Atoms can change into other atoms (d) Chemical reactions involve rearrangement of atoms Q125. Which law is explained by Dalton’s theory? (a) Law of conservation of mass (b) Law of constant proportion (c) Law of multiple proportion (d) all

Q126. Which is NOT correct: (a) Atoms of an element have identical properties (b) Atoms of different elements can have the same mass (c) Atoms cannot be destroyed (d) Atoms combine in simple ratios Q127. Isotopes are atoms having: (a) same Z, different A (b) same A, different Z (c) same n, different p (d) same p, different n Q128. Isobars are: (a) same A, different Z (b) same Z, different A (c) same n, different A (d) same A, different n Q129. Isotones are: (a) same n, different Z (b) same p, different n (c) same A, different Z (d) same Z, different A Q130. Isoelectronic species have: (a) same electrons (b) same protons (c) same neutrons (d) same mass Q131. Which pair is isoelectronic? (a) N³ , O²⁻ ⁻ (b) Na , Ne (c) F , O²⁺ ⁻ ⁻(d) all Q132. Isodiaphers have: (a) same difference between neutrons and protons (b) same mass number (c) same protons (d) same electrons Q133. Isosters have: (a) same number of atoms & electrons (b) same number of protons (c) same Z (d) same n Q134. Which pair is isobaric? (a) ¹⁴C, ¹⁴N (b) ¹⁶O, ¹⁶N (c) ³⁷Cl, ³⁷Ar (d) ¹²C, ¹³C Q135. Law of conservation of mass was proposed by: (a) Lavoisier (b) Dalton (c) Proust (d) Gay- Lussac Q136. Law of constant proportion states: (a) compounds always contain same elements in fixed ratio (b) elements combine in whole numbers (c) mass is conserved (d) all Q137. Law of multiple proportion is given by: (a) Dalton (b) Lavoisier (c) Proust (d) Avogadro Q138. Which law is illustrated by H O₂ ₂ and H O? (a) multiple proportion (b) constant₂ proportion (c) conservation of mass (d) reciprocal proportion Q139. Law of reciprocal proportion states: (a) if elements A and B separately combine with C, the ratio of masses of A and B that combine with same mass of C is same as ratio in which A and B combine with each other (b) mass is conserved (c) all compounds have same ratio (d) none Q140. Which reaction follows law of conservation of mass? (a) CaCO ₃ → CaO + CO ₂ (b) 2H ₂+ O ₂ → 2H O (c) C + O₂ ₂ → CO ₂(d) all Q141. Which is correct according to Dalton? (a) atoms are indivisible (b) atoms of an element are identical (c) atoms combine in simple ratios (d) all

(d) 6 Q153. The value 7.89 rounded to 2 significant figures is: (a) 7. (b) 8. © 7. (d) 7. Q154. The result of 3.456 + 2.1 (to the correct number of significant figures) is: (a) 5. (b) 5. © 5. (d) 5. Q155. Which of the following has the highest precision? (a) 5.2 cm (b) 5.21 cm © 5.213 cm (d) 5 cm Q156. Which statement about accuracy is correct? (a) It is the closeness of measurements to each other (b) It is the closeness of a measurement to the true value © It is unaffected by systematic errors (d) It is the same as precision

Q157. Which is NOT a base quantity in SI units? (a) Length (b) Time © Mass (d) Force Q158. Which is the SI unit of luminous intensity? (a) Candela (b) Lumen © Lux (d) Watt Q159. Which of the following is a physical property? (a) Rusting of iron (b) Melting point of ice © Burning of paper (d) Digestion of food Q160. Which of the following is a chemical property? (a) Colour (b) Density © Reactivity with oxygen (d) Boiling point Q161. The Celsius equivalent of 300 K is: (a) 26°C

(d) Bohr Q166. Which of the following is NOT a postulate of Dalton’s Atomic Theory? (a) Atoms are indivisible (b) Atoms of different elements have different masses © Atoms can be created or destroyed (d) Atoms combine in whole number ratios Q167. Which discovery disproved Dalton’s idea that atoms are indivisible? (a) Discovery of isotopes (b) Discovery of electron © Discovery of proton (d) Discovery of neutron Q168. Which pair are isotopes? (a) ¹²C and ¹³C (b) ¹⁴C and ¹⁴N © ²H and ³He (d) ¹⁶O and ¹⁶S Q169. Which are isobars? (a) ¹⁴C and ¹⁴N (b) ¹²C and ¹³C © ²H and ³H (d) ¹⁶O and ¹⁸O

Q170. Isotones have: (a) Same number of protons (b) Same number of neutrons © Same number of nucleons (d) Same number of electrons Q171. Which pair are isotones? (a) ¹³C and ¹⁴N (b) ¹²C and ¹²O © ¹⁶O and ¹⁶N (d) ¹⁷O and ¹⁸O Q172. Isoelectronic species have: (a) Same number of protons (b) Same number of neutrons © Same number of electrons (d) Same mass number Q173. Which pair is isoelectronic? (a) N³ ⁻ and O²⁻ (b) Na ⁺ and Mg²⁺ © F ⁻and Ne (d) All of these Q174. Which law states that a chemical compound always contains the same proportion of elements by mass? (a) Law of multiple proportions