Important Question for ssc exams

.1.Brass gets discoloured in air because of the presence of which of the following gases in air?
A.Oxygen
B.Hydrogen sulphide
C.Carbon dioxide
D.Nitrogen
Answer: Option B

2.Which of the following is a non metal that remains liquid at room temperature?
A.Phosphorous
B.Bromine
C.Chlorine
D.Helium
Answer: Option B

3.Chlorophyll is a naturally occurring chelate compound in which central metal is
A.copper
B.magnesium
C.iron
D.calcium
Answer: Option B

4.Which of the following is used in pencils?
A.Graphite
B.Silicon
C.Charcoal
D.Phosphorous
Answer: Option A

5.Which of the following metals forms an amalgam with other metals?
A.Tin
B.Mercury
C.Lead
D.Zinc
Answer: Option B

6.Chemical formula for water is
A.NaAlO2
B.H2O
C.Al2O3
D.CaSiO3
Answer: Option B

7.The gas usually filled in the electric bulb is
A.nitrogen
B.hydrogen
C.carbon dioxide
D.oxygen
Answer: Option A

8.Washing soda is the common name for
A.Sodium carbonate
B.Calcium bicarbonate
C.Sodium bicarbonate
D.Calcium carbonate
Answer: Option A

9.Quartz crystals normally used in quartz clocks etc. is chemically
A.silicon dioxide
B.germanium oxide
C.a mixture of germanium oxide and silicon dioxide
D.sodium silicate
Answer: Option A

10.Which of the gas is not known as green house gas?
A.Methane
B.Nitrous oxide
C.Carbon dioxide
D.Hydrogen
Answer: Option D