CBSE Class 11 Chemistry Some Basic Concepts of Chemistry MCQs Set B

Question: A mixture of sand and iodine can be separated by

• a) sublimation
• b) crystallisation
• c) distillation
• d) fractionation

Answer: sublimation

Question: Difference in density is the basis of

• a) gravity separation
• b) molecular sieving
• c) ultrafiltration
• d) molecular attraction

Answer: gravity separation

Question: Which of the following is an example of a heterogeneous substance?

• a) Candle
• b) Pieces of copper
• c) Table salt
• d) Bottled water

Answer: Candle

Question: Which of the following substances cannot be separated in

• a) Solid glucose
• b) Salt and sugar
• c) Sugar and water solution
• d) None of these

Answer: Solid glucose

Question: Which of the following statements about a compound is incorrect?

• a) A compound retains the physical properties of its constituent elements.
• b) The ratio of atoms of different elements in a compound is fixed
• c) A compound cannot be separated into its constituent elements by physical methods of separation.
• d) A molecule of a compound has atoms of different elements.

Answer: A compound retains the physical properties of its constituent elements.

Question: A mixture contains two or more substances in ________

which are called its ________.

• a) any ratio, components
• b) fixed ratio, elements
• c) any ratio, elements
• d) fixed ratio, compounds

Answer: any ratio, components

Question: Which one of these is not a pure compound?

• a) Sucrose solution
• b) H₂O₂
• c) O₃
• d) H₂O

Answer: Sucrose solution

Question: One fermi is

• a) 10^–13 cm
• b) 10^–12 cm
• c) 10^–15 cm
• d) 10^–10 cm

Answer: 10^–13 cm

Question: The prefix 10¹⁸ is

• a) exa
• b) giga
• c) kilo
• d) nano

Answer: exa

Question: The prefix zepto stands for (in m)

• a) 10^–21
• b) 10^–12
• c) 10⁹
• d) 10^–15

Answer: 10^–21

More Questions...............................

Question: Which has highest weight ?

• a) 1 m³ of water
• b) 10 litre of Hg
• c) A normal adult man
• d) All have same weight

Answer: 1 m³ of water

Question: Which one of the following set of units represents the smallest and largest amount of energy respectively?

• a) eV and L-atm
• b) erg and cal
• c) J and erg
• d) cal and eV

Answer: eV and L-atm

Question: A measured temperature on Fahrenheit scale is 200 °F. What will this reading be on Celsius scale ?

• a) 93.3 °C
• b) 40° C
• c) 94° C
• d) 30° C

Answer: 93.3 °C

Question: Which of the following is not a SI unit?

• a) litre
• b) candela
• c) metre
• d) mole

Answer: litre

Question: The prefix 10^–24 is

• a) yocto
• b) yotta
• c) zeta
• d) zepto

Answer: yocto

Question: Many countries use Fahrenheit scale for expressing temperature of atmosphere. If temperature in any such country is measured 41°F then what is its value in celcius scale and would you expect hot or cold atmosphere in that country?

• a) 5°C, cold
• b) 15°C, cold
• c) 25°C, normal
• d) 41°C, hot

Answer: 5°C, cold

Question: A sample was weighted using two different balances. The results were

(i) 3.929 g (ii) 4.0 g
How would the weight of the sample be reported?

• a) 3.9 g
• b) 3.93 g
• c) 3g
• d) 3.929 g

Answer: 3.9 g

Question: 0.00016 can be written as ____A ____ in scientific notaiton. Here, A refers to

• a) 1.6 × 10^–4
• b) 24.50 × 10^–9
• c) 24.50 × 10^–7
• d) 2.450 × 10^–8

Answer: 1.6 × 10^–4

Question: If the true value for an experimental result is 6.23 and the results reported by three students X, Y and Z are :

X : 6.18 and 6.28
Y : 6.20 and 6.023
Z : 6.22 and 6.24
Which of the following option is correct :

• a) Both X & Y neither precise nor accurate, Z both precise and accurate.
• b) Both X & Z precise & accurate, Y not precise
• c) X precise and accurate, Y not precise, Z precise
• d) X precise, Y accurate, Z precise and accurate

Answer: Both X & Y neither precise nor accurate, Z both precise and accurate.

Question: The number of significant figures for the three numbers 161 cm, 0.161 cm, 0.0161 cm are

• a) 3,3 and 3 respectively
• b) 3,4 and 4 respectively
• c) 3,4 and 5 respectively
• d) 3,3 and 4 respectively

Answer: 3,3 and 3 respectively