Which one of the following statements is not correct?

Which of the following is not a gaseous air pollutant?

Match List I with List II and select the correct answer using the codes below

A)John Dalton                         1)Law of definite proportion by volume

B)Joseph Proust                      2)Law of multiple proportion

C)Antoine Lavoisier                 3)Law of definite proportion by weight

D)Joseph Louis Gay Lussac      4)Law of conservation of mass

A    B    C     D

Red phosphorous is used in the manufacture of safety matches.This is due to the fact that

Which of the statements regarding to Portland Cement are correct?

1.Silica imparts strength to cement

2.Alumina makes cement quick setting

3.Excess of lime increases strength of cement

4.Calcium sulphate decreases initial setting time of cement

Select the correct answer using the code below