The pH of a 10ml aqueous solution of HCl is 4 The amount of water to be added to this solution in order to change its pH from 4 to 5 is?

1) 30 ml
2) 60 ml
3) 90 ml
4) 120ml 

Oil refineries, paper factories, textile and sugar mills, chemical factories are responsible for water pollution.These industries discharge harmful chemicals into revers and streams, and pollute water. The chemicals released include

1) arsenic

2) lead

3) fluorides

4) all of the above

The most efficient agent for the absorption of SO₃ is:

 1) 80% H₂S0₄.
2) 98% H₂S0₄.
3) 90% H₂S0₄.
4) 20% H₂S0₄

2,3-Dimethyl-2-butene can be prepared by heating which of the following compounds with a strong acid

1) (CH₃)₂C=CH-CH₂CH₃
2) (CH₃)₂CH-CH₂-CH=CH₂
3) (CH₃)₃C-CH=CH₂
4)

The element used by Rutherford in his famous scattering experiment was :

1) tin
2) gold
3) lead
4) silver

The arrangement of (CH₃)₃C−, (CH₃)₂CH−, CH₃CH₂− when attached to benzene or an unsaturated group, in increasing order of inductive effect is

$$1)\;(CH_3)_3C - < (CH_3)_2 CH - < CH_3CH_2 - \\2)\;CH_3CH_2 - < (CH_3)_2 CH - < (CH_3)_3 C- \\3)\;(CH_3)_2 CH - < (CH_3)_3 C - < CH_3CH_2 - \\4)\;(CH_3)_3 C - < (CH_3)CH_2 - < (CH_3)_2 CH-$$

 Nitrobenzene on reaction with conc. HNO₃/H₂SO₄ at 80-100°C forms which one of the following products?

1) 1,2-dinitrobenzene
2) 1,3-dinitrobenzene
3) 1,4-dinitrobenzene
4) 1,2,4-trinitrobenzene

During the electrolysis of fused sodium chloride,the anodic reaction is :

1) Oxidation of sodium ions
2) reduction of sodium ions
3) oxidation of chloride ions
4) reduction of chloride ions 

Silver iodide is used for producing artificial rain because AgI

1)  is insoluble in water

2)  has crystal structure similar to ice

3)  is easy to spray at high altitude

4)  is easy to synthesize

A colourless salt colours a bunsen flame as golden yellow, and, also turns moistened litmus paper into blue colour. The substance is:

1) Na₂CO₃
2) NaCl
3) Cu(OH)₂
4) K₂CO₃