Chemistry Past Questions and Answers

Some properties of chemical substances are mentioned below... i. sour taste ii. slippery touch iii. yields alkaline gas with ammonium salt iv. has pH less than 7 v. turns phenolphthalein pink. Which of the above are NOT typical properties of alkalis?

A I, iv and v
B Iv and v
C I and iv
D Ii and v
E Ii, iii and iv

Question 437:

A certain volume of gas at 298k is heated such that its volume and pressure are now four times the original values. What is the new temperature?

A 18.6k
B 100.0k
C 298.0k
D 1192.0k
E 4768.0k

Question 438:

Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because

A Zinx is not rendered passive by acid
B Hydrogen produced is oxidized to water
C Oxides of nitrogen are produced
D All nitrates are soluble in water
E Trioxonitrate(v)acid is a strong acid

Question 439:

The boiling point of water, ethanol, toluene and butan-2-ol are 373.0k, 351.3k, 383.6k and 372.5k respectively. Which liquid has the highest vapour pressure at 323.0k?

A Water
B Toluene
C Ethanol
D Butan-2-ol
E None

Question 440:

In what respect will two dry samples of nitrogen gas differ from each other if sample 1 is prepared by completely removing CO2 and O2 from air, and sample 2 is prepared by passing purified nitrogen(i)oxide over heated copper? sample 1 is

A Purer than sample 2
B Slightly denser than sample 2
C In all respects the same as sample 2
D Colourless but sample 2 has a light brown colour
E Slightly less reactive than sample 2