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Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

492.

By what amount must the temperature of 200cm3 of Nitrogen at 27°C be increased to double the pressure if the final volume is 150cm3 (Assume ideality)

A.

150°C

B.

177°C

C.

75°C

D.

120°C

Correct answer is A

Parameters given:

V1 = 200 cm3; T1 = 27 + 273 = 300K.

V2 = 150 cm3; T2 = ?

P2 = 2P1.

Using the Ideal Gas Equation:

P1V1T1=P2V2T2

P1×200300=2P1×150T2

23=300T2

T2 = 450K.

= 450K - 273K

= 177°C

177 - 27 = 150

That is the amount by which T1 must be increased.

494.

Which of the following statements does not show Rutherford's account of Nuclear Theory? An atom contains a region

A.

which contains protons and neutrons

B.

which is positively charged

C.

which is massive and can cause deflection of a few projectiles

D.

which is very large and in which close to 98% of projectiles pass undeflected

Correct answer is C

Rutherford's account of Nuclear theory does not include the fact that atoms contain a massive region and cause deflection of from projectiles.

495.

SO3 is not directly dissolved in water in the industrial preparation of H2SO4 by the contact process because

A.

SO3 is an acidic gas

B.

Acid is usually added to water and not water to acid

C.

The reaction between SO3 and water is violently exothermic

D.

SO3 does not dissolve readily in water

Correct answer is C

No explanation has been provided for this answer.