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
Explanation:
What is the scientific name for washing soda?
Sodium carbonate (also known as washing soda or soda ash), Na2CO3 is a sodium salt of carbonic acid.
Scientific name for baking soda?
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula NaHCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. Since it has long been known and is widely used, the salt has many related names such as baking soda, bread soda, cooking soda, and bicarbonate of soda.
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 greenhouse gas?
A. Methane
B. Nitrous oxide
C. Carbon dioxide
D. Hydrogen
Answer: Option D
Explanation:
In order, the most abundant greenhouse gases in Earth's atmosphere are:
* Water vapor
* Carbon dioxide
* Methane
* Nitrous oxide
* ozone
* chlorofluorocarbons
