Q. Heavy water implies
1) deuterated water
2) water which is used in heavy industries such as thermal power
3) water which contains SO2-4 and CI- od calcium and magnesium
4) water which has maximum density
Q. Dead organs are generally stored in formalin. Formalin is
1) aqueous formaldehyde
2) aqueous ferrous sulphate
3) aqueous formic acid
4) aqueous ferric alum
Q. When items of jewellery made of metals such as copper or nickel are placed in a solution having a salt of gold, a thin film of gold is deposited by
1) passing an electric current
2) cooling to below 0 degree C
3) heating above 100 degree C
4) just keeping it for 10 minutes
Q. Rainwater collected after 30 to 40 minutes of raining is not suitable for drinking because it
1) contains dissolved toxic chemicals
2) contains bacteria and dirt
3) is deficient in minerals
4) is acidic
Q. Glass is actually:
1) a vitrifies liquid
2) a crystalline solid
3) an ionic solid
4) an elastic solid
Q. Solutions in test tubes containing H2O and aqueous NaOH can be differentiated with the help of:
1) red litmus
2) blue litmus
3) Na2CO3
4) HCl (aqueous)
Q. A student heated some sulphur in a spatula and collected the gas 'X'. Which one among the following is correct about 'X'?
1) X is SO2 and it turns moist litmus to blue
2) X is SO3 and it turns moist litmus to red
3) X is SO2 and it turns moist litmus to red
4) X is SO3 and it turns dry litmus to blue
Q. When concentrated H2SO4 spills on the surface, it should be immediately cleaned:
1) with a piece of cloth
2) by adding cold water
3) by adding solid Na2Co3
4) by adding solid BaCl2
Q. Which of the statements given below is/are correct?
1. chloride of calcium
2. bicarbonate of calcium
3. sulphate of magnesium
4. bicarbonate of magnesium
Select the correct answer using the code given below:
1) 1 and 3 only
2) 1 only
3) 2 and 4
4) 1, 2 and 3
Q. Which of the following statements about diamond are correct?
1. It is used as a gem in jewellery because of its ability to reflect light.
2. It is a good conductor of electricity
3. It is used for cutting glass, marble stones and other hard materials
4. It is used for drilling of rocks
Select the correct answer using the code given below:
1) 1, 3 and 4
2) 2, 3 and 4
3) 1, 2 and 3
4) 2 and 4 only