(d) Sodium silicate
Ans: (b)
130. The chemical substance which is easily soluble in water is [UPPCS (Pre) 1993]
(a) carbon
(b) nitrogen
(c) ammonia
(d) iodine
Ans: (c)
131. Before X-ray examination (coloured X-ray) of the stomach, pateints are given suitable salt of barium because-
(a) Barium salts are white in colour and this helps stomach to appear clearly
(b) Barium is a good absorber of X-rays and helps stomach to appear clearly
(c) Barium salts are easily available
(d) Barium allows X-rays to pass through the stomach
Ans: (b)
132. Tear gas is : [Uttarakhand PCS 2003]
(a) hydrogen sulphide
(b) chlorine
(c) hydrogen chloride
(d) ammonia
Ans: (b)
133. The most abundantly occurring element in the earth-crust is : [BPSC (Pre) 1998]
(a) oxygen
(b) nitrogen
(c) manganese
(d) silicon
Ans: (a)
134. Which one among the following polymers is used for making bullet proof material? [CDS, 2012]
(a) Polyvinyl Chloride
(b) Polystyrene
(c) Polyethylene
(d) Polyamide
Ans: (b)
135. Oxygen and Ozone are: [CDS, 2012]
(a) allotropes
(b) isotopes
(c) isomers
(d) isobars
Ans: (a)
136. Which one of the following is not a mixture? [COS, 2010]
(a) Toothpaste
(b) Toilet soap
(c) Baking soda
(d) Vinegar
Ans: (c)
137. Which one of the following is the correct sequence of the reactivity order of the elements? [NDA 2010]
(a) Cu > Mg > Zn > Na
(b) Na > Zn > Mg > Cu
(c) Cu > Zn > Mg > Na
(d) Na > Mg > Zn > Cu
Ans: (b)
138. Which of the following is assumed to be the most fundamental chemical in the chemical industry? [BPSC (Pre)
1999]
(a) H2CO3
(b) HNO3
(c) H2SO4
(d) HCI
Ans: (c)
139. The electrolyte used in the car battery is: [BPSC (Pre) 1998]
(a) hydrochloric acid
(b) sulphuric acid
(c) nitric acid
342