101) In vulcanization, natural rubber is heated with
102) Which one of the following does not wet the walls of the glass vessel in which it is kept?
(D) None of these
103) Dialysis is used for people with defective kidneys. It involves the process of
104) The substance coated on plastic tape-recorder tapes is.
(A) Zinc oxide
(B) Manganese oxide
(C) Iron sulphate
(D) Iron oxide
105) Which form of phosphorus is used in safety matches?
(A) White phosphorus
(B) Yellow phosphorus
(C) Red phosphorus
(D) Black phosphorus
106) Permanent hardness of water can be removed by adding
(A) Potassium permanganate
(C) Bleaching powder
(D) Washing soda
107) The first synthetic fiber made by man was
108) Gypsum is added to cement clinker to
(A) Increase the tensile strength of cement
(B) Bind the particles of calcium silicate
(C) Decrease the rate of setting of cement
(D) Facilitate the formation of colloidal gel