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2876
What is the change in the oxidation number of phosphorus in the following reaction?

4P(s) + 5O2(ag) → 2P2O5(s)
  • A. 0 to 2
  • B. 0 to 5
  • C. 4 to 2
  • D. 4 to 5
  • E. 4 to 10
View Answer & Discuss (5) NECO 2003
2877
In the reaction 2H2S(g) + SO2(g) → 2H2SO(I)+3S(s)SO2is acting as _agent
  • A. a bleaching
  • B. a dehydrating
  • C. an oxidizing
  • D. a precipitating
  • E. a reducing
View Answer & Discuss (2) NECO 2003
2878

What is the number of moles of Na\(_H\)CO\(_3\) in 250cm\(^3\) of its solution if the solution contains 8.4 g of Na\(_H\)CO\(_3\) in 1 dm\(^3\) of the solution. [Na = 23, 0 = 16, C = 12, H = 1)

  • A. 1
  • B. 0.25
  • C. 0.05
  • D. 0.025
  • E. 0.01
View Answer & Discuss (10) NECO 2003
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2879

The type of reaction ethyne mainly undergoes is

  • A. addition
  • B. carboxylation.
  • C. esterification
  • D. saponification
  • E. substitution
View Answer & Discuss (5) NECO 2008
2880
Which of the following laws is obeyed If at constant temperature, 200cm of hydrogen at 1.5 × 10m5Nm-2pressure becomes 300cm3 at 1.0 × 105Nm-2 pressure?
  • A. Avogadro’s
  • B. Boyle’s
  • C. Charles’
  • D. Faraday’s
  • E. Graham’s
View Answer & Discuss (4) NECO 2008
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