Question 41. Which one of the following is the correct sequence in increasing order of molecular weights of the hydrocarbons?

Question 42. Corrosion is  electro-chemical oxidation of metals in reaction with an oxidant such as  oxygen. Aluminium surface are often' anodized'. This means the deposition of a layer of

Question 43. When the temperature of a gas sample filled in a container is increased, its pressure increases. Which of the following are the reasons for it?
(a) Gas molecules exert more force on each other than before.
(b) Gas molecules move faster than before and strike the walls of the container more often.
(c) Each impact of the gas molecules on the walls of the container yields a greater force then before.
(d) Impacts are now distributed over a smaller area.

Question 44. Which one of the following is a mixed fertilizer?

Question 45. Which one of the following fuels causes minimum environmental pollution?

Question 46. Which of the following statements are true regarding heat?
(a) Heat is a form of energy
(b) Heat can be reflected by a mirror
(c) Heat is an electromagnetic radiation
(d) Heat cannot pass through vacuum

Question 47. Which one of the following polymers is widely used for making bullet proof material?

Question 48. 'Yellow cake', an item of smuggling across border is

Question 49. There is an immense number of distinct compounds that contain carbon atoms. Some sources suggest that there are about ten million known compounds. The number of carbon atoms in the following compounds vary.
What is the increasing order in which they are present in the compounds?
(a) Butane
(b) Methane
(c) Ethane
(d) Decane

Question 50. Which one of the following materials is very hard but very ductile at the same time?