NSMQ 2025 TRIER QUESTIONS AND ANSWERS (TRUE/FALSE).

1. Alkanes undergo free radical substitution.

Ans: True

2. Benzenes do not undergo combusting reactions.

Ans: False

3. Nucleophiles are electron-rich species

Ans: False

4. Nucleophiles are species that must have free electron pairs.

Ans: False. (A carbon–carbon double bond can act as a nucleophile).

5. All the elements in the second period of the Periodic Table form covalent hydrides.

Ans: False (some are ionic)

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6. Ammonia, a hydride of nitrogen, reacts with oxygen in the air at room temperature to give NO gas.

Ans: False (will only react when heated).

7. Hydrides such as NH₃, H₂O, and NaH are referred to as electron-rich hydrides

Ans:  True

8. While lithium hydride is wholly ionic, beryllium hydride is a highly polarized covalent molecule.

Ans: True

9. The activity of a radioactive sample is directly proportional to the number of active nuclei present in the sample.

Ans: True

10. The activity of a radioactive sample decreases with time.

Ans: True

11. All active nuclei present in a radioactive specimen decay during the lifetime of the specimen.

Ans: False

12. The activity of a radioactive substance is completely random

Ans: True

13. The oil used for metal storage must be water-soluble.

Ans: False (It must be water-insoluble, like mineral oil.)

14. Wavelength is the distance between two consecutive crests of a wave.

Ans: True (Standard definition.)

15. Higher frequency waves have longer wavelengths.

Ans: False (Higher frequency = shorter wavelength.)

16. Visible light has wavelengths between 400 nm and 700 nm.

Ans: True (Violet to red light.)

17. Sound waves in air have wavelengths measured in meters.

Ans: True (E.g., 20 Hz sound has ~17 m wavelength.)

18. Linear momentum and velocity vectors always point in the same direction.

Ans: True (Since p = mv, direction matches.)

19. An object’s momentum can change even if its speed is constant.

Ans: True (If direction changes, e.g., circular motion.)

20. A car turning left without changing speed has constant momentum.

Ans: False (Direction changes → momentum changes.)

21. In the absence of external forces, momentum is conserved.

Ans: True (Newton’s first law.)

22. Permutations can be used when selecting a committee from a group.

Ans: False

23. In permutations, the order of items matters.

Ans: True

24. In combinations, repetitions are allowed.

Ans: False

25. The total number of combinations of selecting all possible subsets from a set of elements is 2

Ans: True

26. Two matrices can be added only if they have the same dimensions.

Ans: True

27. The product of a matrix and the identity matrix of compatible size is the matrix itself.

Ans: True

28. A square matrix has an inverse if and only if its determinant is non-zero.

Ans: True

29. The transpose of a matrix is obtained by flipping it over its main diagonal.

Ans: True

30. The frequency of the sound produced by an approaching siren as heard by a stationary observer is greater than the frequency heard when the siren is receding.

Ans: True

31. The frequency of the sound produced by a stationary siren as heard by an approaching observer is the same as the frequency heard by a receding observer.

Ans: False

32. The frequency of the sound produced by an approaching siren as heard by an observer moving towards the siren is greater than the frequency heard when the observer is stationary.

Ans: True

33. The frequency of the sound produced by a stationary siren as heard by an observer moving towards the siren is the same as the frequency heard by a receding observer.

Ans: False

34. Meiosis is the type of cell division that results in the production of zygotes.

Ans: False (gametes)

35. Mitosis consists of two successive divisions.

Ans: False

36. Mitosis is generally followed by equal division of the cell’s content into two daughter cells that have identical genomes.

Ans: True

37. Mitosis helps to preserve and perpetuate the genetic constitution of an organism.

Ans: True

38. The transport of carbon dioxide by the blood is principally dependent on the solubility of carbon dioxide in the blood

Ans: False

39. The transport of carbon dioxide by the blood is principally dependent on the ability of haemoglobin to bind and transfer carbon dioxide.

Ans: False

40. The transport of carbon dioxide by the blood is principally dependent on the presence of carbonic anhydrase in red blood cells.

Ans: True

41. The transport of carbon dioxide by the blood is principally dependent on its partial pressure and the presence of oxyhaemoglobin.

Ans: True

42. The Bohr model explains the emission spectrum of multi-electron atoms accurately.

Ans: False – It only works for hydrogen/hydrogen-like ions (e.g., He⁺).

43. Electrons in the Bohr model move in fixed circular orbits called “stationary states.”

Ans: True – These orbits have quantized angular momentum.

44. The Bohr model violates Heisenberg’s Uncertainty Principle.

Ans: True – It assumes exact electron paths (position/momentum can’t both be known precisely).

45. The energy of an electron in the Bohr model increases as it moves farther from the nucleus.

Ans: True – Energy levels converge as n increases

46. The biosphere includes only the Earth’s surface and oceans.

Ans: False – It spans the atmosphere (up to 8 km), lithosphere, and hydrosphere.

47. Photosynthetic organisms in the biosphere produce most of the Earth’s oxygen.

Ans: True – Algae and plants contribute ~70% of atmospheric O₂.

48. The biosphere interacts with the atmosphere but not the geosphere.

Ans: False – It interacts with all Earth systems (e.g., weathering by lichens).

49. The ozone layer is part of the biosphere.

Ans: False – It’s in the stratosphere (abiotic part of the atmosphere).

50. Homogeneous catalysts are in the same phase as the reactants.

Ans: True – Example: H⁺ ions (aqueous) catalyzing ester hydrolysis.

51. Heterogeneous catalysts increase reaction rates by lowering activation energy.

Ans: True – They provide active sites (e.g., Pt in catalytic converters).

52. Enzymes are examples of heterogeneous catalysts.

Ans: False – They’re homogeneous (same phase as substrates).

53. Homogeneous catalysts are easier to separate from products than heterogeneous ones.

Ans: False – Heterogeneous catalysts (e.g., solid Pt) are easily filtered out.

Preamble: For a monoatomic idea gas,

54. At constant pressure, volume is directly proportional to temperature (Charles’s Law).

Ans: True

55. The internal energy of a monoatomic ideal gas depends only on its pressure.

Ans: False – It depends on temperature

56. Work done by the gas during expansion equals PΔV

Ans: True

57. The graph of y = (x – 3)² is the same as the graph of y = x², but moved 3 units to the right.

Ans: True

58. The graph of y = x² – 4 is the same as the graph of y = x², but moved 4 units to the right.

Ans: False

59. The graph of y = x² + 1 is the same as the graph of y = x², but moved 1 unit up.

Ans: True

60. The graph of y = – x² is the same as the graph of y = x², but is reflected across the y-axis.

Ans: False

61. A circle is the set of points in a plane that are equidistant from a given fixed point.

Ans: True

62. A line segment determined by the center and any point on the circle is called the diameter.

Ans: False

63. The circle x² + y² = 16 has its center at the origin.

Ans: True

64. The circle (x – 4)² + (y + 3)² =10 has a center in the second quadrant.

Ans: False

65. The heat capacity at constant pressure is less than at constant volume

Ans: False

66. A higher Ka value indicates a stronger acid

Ans: True

67. Ka is a dimensionless quantity

Ans: False

68. Ka depends on the concentration of the acid solution

Ans: True

69. pKa = -log Ka, so a lower pKa means weaker acidity

Ans: False

70. Secretin is produced by the stomach lining.

Ans: False – It’s secreted by the duodenum (small intestine).

71. Secretin stimulates the pancreas to release bicarbonate.

Ans: True – Neutralizes stomach acid in the duodenum.

72. Secretin inhibits gastric acid secretion in the stomach.

Ans: True – Part of a negative feedback loop.

73. Secretin is a steroid hormone.

Ans: False – It’s a peptide hormone (27 amino acids).

74. The derivative of a constant is zero.

Ans: True

75. The integral of a function gives the area under the curve.

Ans: True

76. If a function is differentiable, it must also be continuous.

Ans: True

77. The derivative of sin x is − cos x

Ans: False

78. The axis of symmetry of a parabola always passes through the y-axis.

Ans:  False

79. The focus of a parabola is always inside the curve.

Ans: True

80. For a parabola, the directrix is always parallel to the x-axis.

Ans: False

81. A parabola can have more than one axis of symmetry.

Ans: False

82. The enthalpy of combustion of diamond is the same as the enthalpy of formation of carbon dioxide

Ans: False

83. The enthalpy of combustion of C₂H₄ is equivalent to the enthalpy of formation of carbon dioxide and water

Ans: False

84. The enthalpy of neutralization of a strong acid is equivalent to the enthalpy of formation of water

Ans: True

85. The enthalpy of combustion of hydrogen gas is the same as the enthalpy of formation of water

Ans: True

86. The hydrogen bond in NH₃ is greater than that of H₂

Ans: False

87. The greater the electronegativity of the element attached to Hydrogen, the weaker the polarization of the bond.

Ans: False

88. The hydrogen bond in the N-H bond is weaker than that of the O-H bond.

Ans: False

89. The strength of a dipole–dipole is dependent on the electronegativity difference between the bonding atoms.

Ans: True

90. The electrical resistance of a metal increases as the temperature increases.

Ans:  True

91. The electrical resistance of a semiconductor increases as the temperature is increased.

Ans:  False

92. A magnetic field decreases the magnitude of the Hall coefficient.

Ans:  True

93. The presence of a magnetic field increases the resistivity of semiconductors.

Ans: True

94. The electromotive force of a battery comprising three identical cells in series equals three times the electromotive force of one of the cells.

Ans: True

95. The electromotive force of a battery comprising two identical cells in parallel equals half the electromotive force of one of the cells.

Ans: False

96. The internal resistance of a battery comprising two identical cells in parallel equals half the internal resistance of one of the cells.

Ans: True

97. The internal resistances of a battery comprising two identical cells in parallel are also parallel

Ans: True

98. tan²A = sec²A + 1.

Ans: False

99. cot²A = cosec²A – 1.

Ans: True

100. cos²A – sin²A = 1.

Ans: False

101. cos²A – sin²A = -1.

Ans: False

• NSMQ 2022 BIOLOGY PAST QUESTIONS AND ANSWERS.

• NSMQ 2022 Quarter Final Problem of the Day Questions and Answers.

• NSMQ2023; (ABOUT 234) PHYSICS TRUE OR FALSE PAST QUESTION AND ANSWER.

102. Primary alkanols have the –OH group attached to a carbon bonded to only one other carbon.

Ans: True (e.g., ethanol).

103. Tertiary alkanols can be oxidized to form aldehydes.

Ans: False (They resist oxidation due to steric hindrance).

104. Secondary alkanols have two alkyl groups attached to the carbon bearing the –OH group.

Ans: True (e.g., isopropanol).

105. Methanol is a tertiary alkanol.

Ans: False (It’s primary; the –OH is on a carbon with no alkyl groups).

106. Mushrooms are photosynthetic organisms.

Ans: False (They are fungi and decompose organic matter).

107. The visible part of a mushroom is its reproductive structure.

Ans: True (The fruiting body produces spores).

108. All mushrooms are edible.

Ans: False (Some are highly toxic, e.g., death cap).

109. Mushrooms belong to the plant kingdom.

Ans: False (They are in the fungi kingdom).

Preamble: An object moves in a circle with constant speed:

110. The velocity of the object is constant.

Ans: False (Direction changes, so velocity is not constant).

111. The acceleration is directed toward the center of the circle.

Ans: True (Centripetal acceleration).

112. The kinetic energy of the object remains constant.

Ans: True (Speed is constant, so KE = ½mv² is unchanged).

113. No work is done on the object because the speed is constant.

Ans: False (Work is zero if force is perpendicular to displacement).

114. The oxidation state of oxygen is always –2.

Ans: False (Exceptions: peroxides like H₂O₂, where it’s –1).

115. In NaCl, chlorine has an oxidation state of –1.

Ans: True.

116. The oxidation state of sulphur in H₂SO₄ is +6.

Ans: True.

117. Free elements (e.g., O₂) always have an oxidation state of zero.

Ans: True.

118. Antibiotics are effective against viral infections.

Ans: False (Only works on bacteria).

119. Fever is always a symptom of bacterial infection.

Ans: False (Can also occur in viral infections or inflammation).

120. All bacteria are harmful to humans.

Ans: False (e.g., gut microbiota is beneficial).

121. Tuberculosis is caused by a bacterium.

Ans: True (Mycobacterium tuberculosis).

122. 1 kilometre is equivalent to 1000 meters.

Ans: True.

123. 1 litre is equal to 1000 cubic centimetres (cm³).

Ans: True.

124. 1 watt-hour is equivalent to 3600 joules.

Ans: True (1 W = 1 J/s; 1 hour = 3600 s).

125. 1 atmosphere (atm) is exactly 760 mmHg.

Ans: True (Standard definition).

126. A rational function is the ratio of two polynomials.

Ans: True

127. A rational function can never have vertical asymptotes.

Ans: False

128. If the degree of the numerator is greater than the degree of the denominator, the rational function has a horizontal asymptote at = 0

Ans: False

129. A rational function can have both vertical and horizontal asymptotes.

Ans: True

130. A statement that is always true, regardless of the truth values of its components, is called a tautology.

Ans: True

131. The negation of a false statement is always true.

Ans: True

132. The disjunction (OR) of two false statements is false.

Ans: True

133. The conjunction (AND) of two true statements is false.

Ans: False

134. Time is a discrete variable.

Ans: False

135. The number of students in a school is a discrete variable.

Ans: True

136. The height of a student is a continuous variable.

Ans: True

137. The set of whole numbers is a discrete variable

Ans: True

138. Amphibians are more closely related to bony fishes than to reptiles

Ans: True

139. The lateral line system is more developed in amphibians than in bony fishes.

Ans: False

140. The sense of vision is more developed in amphibians than in bony fishes.

Ans: True

141. The sense of smell is more developed in bony fishes than in amphibians.

Ans: True

142. The lower portion of the pistil of a flower produces pollen.

Ans: False

143. A gametophyte is the diploid multicellular stage in the alternation of generations life cycle of plants and algae.

Ans: False (Haploid)

144. In bryophytes, the sporophyte represents the longer-lived, nutritionally independent, and more visible stage of the life cycle.

Ans: False

145. The sporophyte of a moss contains no chlorophyll of its own and grows parasitically on its gametophyte mother

Ans: True

146. Energy in reflected light does not depend on the angle of incidence

Ans: False

147. Energy in reflected light increases with the increase in angle

Ans: False

148. Energy in reflected light decreases with the increase in angle of incidence

Ans: False

149. Energy in reflected light becomes maximum for an angle of incidence equal to 45°

Ans: True

150. An electric field is most directly related to the potential energy of a test charge.

Ans: False

151. As used in the definition of electric field, a “test charge” has zero charge.

Ans: False

152. A test charge is a conventional charge and can be negative or positive

Ans: True

153. Electric field lines are trajectories of a test charge.

Ans: False

PREAMBLE: During the electrolysis of copper (II) sulphate using platinum electrodes, the addition of litmus solution to the anode compartment will result in.

154. The litmus turns blue, but no gas is evolved.

Ans: False

155. The litmus turns blue, and oxygen gas is evolved

Ans: False

156. The litmus turns red, and hydrogen gas is evolved

Ans: False

157. The litmus turns blue, and hydrogen gas is evolved.

Ans: False

158. HCl is a more concentrated acid than CH₃COOH because it dissociates to a greater extent to produce more H⁺ ions in solution

Ans: False

159. Because HNO₃ has a bigger Ka than HF, it is a stronger acid

Ans: True

160. Phenol is a stronger acid than water because the phenoxide ion formed after the loss of the H⁺ ion is stabilized by resonance.

Ans: True

161. HClO₃ is a stronger acid than HClO because the central atom in HClO₃ has a lower oxidation number.

Ans: False

162. Glycolysis occurs in the mitochondria.

Ans:    False

163. Glycolysis can occur with or without oxygen.

Ans:    True

164. Glycolysis is the first step in both aerobic and anaerobic respiration.

Ans:    True

165. Glycolysis is a reversible process

Ans: False

166. Gills replace lungs during the metamorphosis of tadpoles to toads.

Ans: False

167. The Tail disappears during the metamorphosis of frogs.

Ans: True

168. Limbs disappear during the metamorphosis of frogs.

Ans: False

169. The thyroxine and growth hormone are responsible for metamorphosis in frogs

Ans: False

170. Under a reflection in the x-axis, the point (x, y) → (x, -y).

Ans:    True

171. Under a reflection in the y-axis, the point (x, y) → (-x, y).

Ans:    True

172. Under a reflection in the origin, the point (x, y) → (-y, -x).

Ans:     False

173. Under a reflection in the y = x, the point (x, y) → (y, x).

Ans:    True

174. If the discriminant is positive, the roots of a quadratic equation are positive.

Ans: False

175. If the discriminant is negative, the roots of a quadratic equation are negative.

Ans: False

176. If the discriminant is zero, the roots of a quadratic equation are equal.

Ans: True

177. The discriminant tells how many solutions a quadratic function has.

Ans: False

178. The resultant of two equal forces inclined at 120° is equal to the magnitude of one force.

Ans: True (Resultant = √(F²+ F² + 2F²cos120°) = F)

179. If two forces of magnitude 10 N each act at 90°, their resultant is 10√2 N.

Ans: True (R = √(10² + 10²) = 10√2 N)

180. Two equal forces at 180° cancel each other out.

Ans: True (Resultant = F – F = 0)

181. The resultant of two equal forces at 60° is greater than either force.

Ans: True (R = √(F² + F² + 2F²cos60°) = F√3 > F)

182. An oxidizing agent gains electrons during a reaction.

Ans: True (Oxidizing agents are reduced by accepting electrons)

183. In the reaction Zn + Cu²⁺ → Zn²⁺ + Cu, Cu²⁺ is the oxidizing agent.

Ans: True (Cu²⁺ oxidizes Zn by accepting electrons)

184. A strong reducing agent is a weak oxidizing agent.

Ans: True (They are inversely related in redox potential)

185. Oxygen is always the oxidizing agent in combustion reactions.

Ans: False (Not always; e.g., fluorine can oxidize oxygen in OF₂ formation)

186. Two coherent waves of the same frequency will always interfere constructively.

Ans: False (Depends on phase difference; destructive if out of phase by π)

187. Beats are produced when two waves of slightly different frequencies interfere.

Ans: True (Beat frequency = |f₁ – f₂|)

188. Two sound waves of the same frequency must have the same wavelength in air.

Ans: True (λ = v/f, where v is constant in the same medium)

189. Two light waves of the same frequency will have the same speed in glass.

Ans: False (Speed depends on refractive index, which varies with wavelength)

190. Phototropism is plant growth in response to light.

Ans: True (Shoots grow toward light)

191. Gravitropism in roots is always negative (grows upward).

Ans: False (Roots show positive gravitropism—grow downward)

192. Thigmotropism is a response to touch (e.g., vines coiling around supports).

Ans: True

193. Hydrotropism is movement toward water, independent of gravity.

Ans: True (Roots grow toward moisture even if upward)

194. The ozone layer absorbs most of the Sun’s ultraviolet (UV) radiation.

Ans: True (Blocks 97–99% of UV-B and UV-C)

195. CFCs (chlorofluorocarbons) are the primary cause of ozone depletion.

Ans: True (They release chlorine radicals that destroy ozone)

196. The ozone hole is a region where ozone concentration increases.

Ans: False (It’s a region of severe ozone depletion).

197. Ground-level ozone is beneficial for protecting life from UV rays.

Ans: False (Only stratospheric ozone is protective; ground-level ozone is a pollutant)

198. All animals are heterotrophs.

Ans: True (They rely on organic carbon for energy)

199. Fungi are heterotrophs that decompose organic matter.

Ans: True (Saprophytic nutrition)

200. Parasitic plants like mistletoe are autotrophs.

Ans: False (They are partial heterotrophs, stealing nutrients from hosts)

201. Heterotrophs produce their own food via photosynthesis.

Ans: False (Only autotrophs do this; heterotrophs consume others)

202. The angle at the center of a circle is twice the angle at the circumference subtended by the same arc.

Ans:  True

203. Angles in the same segment of a circle are always equal.

Ans: True

204. A tangent to a circle is perpendicular to the radius drawn to the point of contact.

Ans: True

205. The opposite angles of a cyclic quadrilateral add up to 90°.

Ans: False

206. The gradient (slope) of a vertical line is always zero.

Ans: False

207. Two lines are perpendicular if the product of their gradients is −1.

Ans: True

208. The equation of a straight line in slope-intercept form is y = mx + by, where mmm is the x- intercept.

Ans: False

209. The x-coordinate of any point on the y-axis is zero.

Ans: True

210. All woody plants are perennial.

Ans: True (They live for multiple years.)

211. Herbaceous plants develop a thick, lignified stem.

Ans: False (Woody plants do; herbaceous plants have soft stems.)

212. Bamboo is classified as a woody plant.

Ans: True (Despite its grass-like appearance, it has lignin.)

213. Woody plants cannot photosynthesize.

Ans: False (Their leaves and green stems can photosynthesize.)

214. All ants are social insects that live in colonies.

Ans: True (They are eusocial.)

215. Ants have a pair of wings throughout their adult lives.

Ans: False (Only reproductive ants have wings temporarily.)

216. Ants communicate solely through sound.

Ans: False (They use pheromones, touch, and vibrations.)

217. Worker ants are always sterile females.

Ans: True (In most species, workers are infertile females.)

218. The rate-determining step is the fastest in a reaction mechanism.

Ans: False (It’s the slowest step.)

219. Changing the concentration of a reactant in the rate-determining step affects the overall reaction rate.

Ans: True (It directly impacts the rate.)

220. The rate law of a reaction is based on the stoichiometry of the overall equation.

Ans: False (It’s derived from the rate-determining step.)

221. Catalysts speed up reactions by altering the rate-determining step.

Ans: True (They provide an alternative pathway with lower activation energy.)

222. Sodium is stored in oil to prevent contact with water vapor.

Ans: True (It reacts violently with water.)

223. Lithium can be safely stored in open air.

Ans: False (It tarnishes quickly; oil storage is needed.)

224. Potassium is less reactive than sodium, so it doesn’t require oil storage.

Ans: False (Potassium is more reactive and needs oil.)

225. Algology is the study of algae.

Ans: True

226. Unicellular Algae are members of Protista.

Ans: True

227. Bacillariophyta are dinoflagellates.

Ans: False

228. Dinoflagellates are bioluminescent.

Ans: True

229. Bacillariophyta are mostly heterotrophs.

Ans: False. (Diatoms are mostly autotrophs)

Preamble:  Consider these statements about X-rays and Ultraviolet radiation

230. X-rays travel faster in a vacuum than ultraviolet rays.

Ans: False

231. X-rays have shorter wavelengths than Ultraviolet rays.

Ans: True

232. X-rays cannot be diffracted, unlike ultraviolet waves.

Ans: False

233. X-rays have a higher penetrating ability than Ultraviolet rays.

Ans: True

234. X-rays have a lower frequency than ultraviolet waves.

Ans: False

Preamble:  This is a prime number.

235. 253

Ans: False

236. 257

Ans: True

237. 277

Ans: True

238. 283

Ans: True

239. 381

Ans: False

Preamble:   Brine is a concentrated aqueous sodium chloride. Brine is electrolyzed in a diaphragm cell; some of the main purposes of the diaphragm are to . . .

240. Prevent NaOH from reacting with HCl.

Ans: False

241. Prevent NaOH from reacting with Cl₂

Ans: True

242. Prevent Cl₂ from reacting with H₂

Ans: False

243. Prevent HCl from reacting with Na

Ans: False

244. Prevent backflow so Cl₂ doesn’t recombine with H₂.

Ans: True

Preamble:  Some of the major reasons that make tongue rolling a discontinuous variation is that;

245. There are many different types of tongue rollers.

Ans: False

246. A person can roll their tongue only when they are young.

Ans: False

247. It is not solely determined by a single dominant gene.

Ans: True

248. Tongue rolling has to be learnt.

Ans: False

249. Tongue rolling is something that a person can or cannot do.

Ans: True

Preamble:   A parallel-plate capacitor is connected to a battery; a sheet of dielectric material is inserted between the plates without disconnecting the battery . . .

250. The Charge stored decreases

Ans: False

251. The energy stored is unchanged

Ans: False

252. The energy stored increases

Ans: True

253. The potential difference between the plates decreases

Ans: False

254. The capacitance is unchanged

Ans: False

Preamble: In a cyclic quadrilateral;

255. The sum of the product of the opposite sides equals the product of the diagonals.

Ans: True

256. All four vertices of the inscribed quadrilateral lie on the circumference, but they are not concyclic.

Ans: False (They are concyclic)

257. The perpendicular bisectors of the sides are not always concurrent.

Ans: False (Always concurrent)

258. The sum of a pair of opposite angles is always supplementary.

Ans: True

259. The measure of an exterior angle at a vertex equals the opposite exterior angle.

Ans: False.

Preamble: When combined in appropriate molar ratios, the following can form a buffer solution;

260. HCHO₂ and NaCHO₂

Ans: True

261. NaOH and HCOONa

Ans: False

262. NH₄Cl and HCl

Ans: False

263. HCl and NH₃

Ans: True

264. HCl and NaCl

Ans: False

Preamble: This reaction is endothermic;

265. The decomposition of Calcium Carbonate.

Ans: True

266. The burning of magnesium ribbon.

Ans: False

267. Thermal decomposition of limestone.

Ans: True

268. The combustion of methane.

Ans: False

269. The reaction of water with anhydrous copper (II) Sulphate.

Ans: False

270. An object with a changing speed will always have a changing momentum.

Ans: True

271. Two colliding objects will exert equal forces upon each other, even if their mass is significantly different.

Ans: True

272. During a collision, an object does not always encounter an impulse and a change in momentum.

Ans: False

273. The velocity change of two respective objects involved in a collision will always be equal.

Ans: True

274. In a collision, the net impulse experienced by an object is equal to its momentum change.

Ans: True

Preamble: This is a reserve food of some Algae.

275. Leucosin

Ans: True

276. Laminapos

Ans: False

277. Floridian Starch

Ans: True

278. Moreens

Ans: False

279. Oils

Ans: True

Preamble:  Copper (II) Sulphate can be prepared by adding excess Copper (II) Carbonate to sulfuric acid. One reason an excess of Copper (II) Carbonate is added is to;

280. To ensure that all the Copper (II) Carbonate has reacted.

Ans: False

281. To increase the rate of the reaction.

Ans: False

282. To ensure all the sulfuric acid has reacted.

Ans: True

283. To increase the yield of Copper II Sulphate.

Ans: False

284. To maintain a stable temperature.

Ans: False

285. If A = {1, 2, 3, 4, 5}, then the number of proper subsets of A is 31.

Ans: True

286. The powerset of a singleton set has a cardinal number of 2.

Ans: True

287. Any singleton set has only a single subset.

Ans: False (it has a null set and the set itself)

288. Between any two irrational numbers is another irrational number.

Ans: True

289. A singleton is always finite.

Ans: True

Preamble: Consider the following statements about elastic and plastic deformation;

290. Elastic deformation and plastic deformation are proportional to the applied force.

Ans: False

291. Elasticity is an intrinsic material property, while plasticity is an extrinsic material property.

Ans: True

292. Elastic deformation and plastic deformation cause no change in volume.

Ans: False

293. Elastic deformation is reversible, but plastic deformation is not reversible.

Ans: True

294. Elastic deformation causes heating of the material, but plastic deformation does not.

Ans: False

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