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Saturday, 08 August 2026
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Chemistry Past Questions and Answers

Chemistry Questions

Question 351:
20 cm <sup style='font-size: smaller;'>3</sup> of hydrogen gas are sparked with 20cm <sup style='font-size: smaller;'>3</sup> of oxygen gas in an endimoeter at 373k (100 <sup style='font-size: smaller;'>o</sup>C) and 1 atmosphere. The resulting mixture is cooled to 298 K (25 <sup style='font-size: smaller;'>o</sup>C) and passed over calcium chloride. The volume of the residual gas is
  • A 40 cm <sup style='font-size: smaller;'>3</sup>
  • B 20 cm <sup style='font-size: smaller;'>3</sup>
  • C 30 cm <sup style='font-size: smaller;'>3</sup>
  • D 10cm <sup style='font-size: smaller;'>3</sup>
  • E 5cm <sup style='font-size: smaller;'>3</sup>
View Answer & Explanation
Question 352:
For the reaction NH4NO2 \(\to\) N2 + 2H2O, calculate the volume of nitrogen that would be produced at S. T. P from 3.2 g of the dioxonitrate(iii)salt. (Relative atomic masses: N = 14, O = 16, H = 1)
  • A 2.24 dm <sup style='font-size: smaller;'>3</sup>
  • B 2.24 cm<sup style='font-size: smaller;'>3</sup>
  • C 1. 12<sup style='font-size: smaller;'>3</sup>
  • D 1. 12dm <sup style='font-size: smaller;'>3</sup>
  • E 4. 48 dm <sup style='font-size: smaller;'>3</sup>
View Answer & Explanation
Question 353:
A molar solution of caustic soda is prepared by dissolving
  • A 40 g NaOH in 100 g of water
  • B 40 g NaOH in 1000 g of water
  • C 20 g NaOH in 500 of solution
  • D 20 g NaOH in 1000 g of solution
  • E 2o g NaOH in 80 g of solution
View Answer & Explanation
Question 354:
Which among the elements 1. Carbon 2. Oxygen 3. Copper 4. Bromine 5. Zinc, will NOT react with either water or steam?
  • A 1 and 2
  • B 2 and 3
  • C 3 and 4
  • D 1, 2, and 3
  • E 2, 3, and 5
View Answer & Explanation
Question 355:
Naphthalene when heated melts at 354 K (81 <sup style='font-size: smaller;'>o</sup>C). At this temperature the molecules of naphthalene
  • A Decompose into smaller molecules
  • B Change their shape
  • C Are oxidized by atmospheric oxygen
  • D Contract
  • E Become mobile as the inter molecular forces are broken
View Answer & Explanation