Class 9 Science MCQ Questions Structure of the Atom with Answers

MCQ Questions for Class 9 Science Chapter 4 Structure of the Atom with Answers

Q1. Which of the following has largest number of particles?
8g of `CH_{4}`
4.4g of `CO_{2}`
 34.2g of `C_{12}H_{22}C_{11}`
2g of `H_{2}`

Q2. The number of molecules in 16.0g of oxygen is:
6.02 `\times 10^{23}`
6.02 `\times 10^{-23}`
3.01 `\times 10^{-23}`
3.01 `\times 10^{23}`

Q3. The percentage of hydrogen in `\H_{2}`O is
8.88
11.12
20.60
80.0

Q4. Find the mass of oxygen contained in 1 kg of potassium nitrate `\KNO_{3}`
475.5g
485.5g
475.2g
485.2g    

Q5. How many moles of electron weight one kilogram?
6.023 `\times 10^{23}`
6.023 `\times 10^{8}`
9.108 `\times 10^{54}`
1.82 `\times 10^{8}`

Q6. 25.4g of iodine and 14.2g of chlorine are made to react completely to yield a mixture of `\ICl` and `\ICl_{3}`. Calculate the ratio of moles of `\ICl` and `\ICl_{3}`
1:1
2:1
3:1
1:2

Q7. The mass of sodium in 11.7 g of sodium chloride is:
2.3g
4.6g
6.9g
7.1g

Q8. The formula of a chloride of a metal M is `\MCl_{3}`. The formula of the phosphate of metal M will be:
`\MPO_{4}`
`\M_{2}PO_{4}`
`\M_{3}PO_{4}`
`\M_{2}(PO_{4})_{3}`

Q9. Which of the following contains the largest number of molecules?
0.2 mol 0f `\H_{2}`
8.0 g of `\H_{2}`
17 g of `\H_{2}O`
6.0 g of `\CO_{2}`

Q10. One gram of which of the following contains largest number of oxygen atoms?
`\O`
`\O_{2}`
`\O_{3}`
All contain same

Q11. The percentage by weight of `\O_{2}` in `\CaSO_{4}` (O = 16, S = 32, Ca = 40) is:
64
28.2
47.2
16.2

Q12. The percentage by weight of Zn in white vitriol, `\ZnSO_{4}.7H_{2}O` (Zn = 65, S = 32. O = 16, H = 1) is approximately:
23
33
43
13

Q13. The formation of `\SO_{2}` and `\SO_{3}` explain:
The law of conservation of mass
The law of multiple proportions
The law of definite properties
Boyle's law

Q14. The law of definite proportions was given by:
John Dalton
Humphry davy
Proust
Michael Faraday

Q15. Molecular mass is defined as the:
Mass of one atom compared with the mass of one molecule
Mass f one atom compared with the mass of one atom of hydrogen
Mass of one molecule of any substance compared with the mass of one atom of C – 12
None of the above

Q16. 0.001 g of C is required t write a letter with a graphite pencil. The total number of C atoms used in writing the letter is:
5.00 `\times 10^{12}`
5 `\times 10^{19}`
5.0 `\times 10^{24}`
6.023 `\times 10^{23}`

Q17. One mole of a gas occupies a volume of 22.4 L. This is derived from:
Berzelius’s hypothesis
Gay- Lussac’s law
Avogadro’s law
Dalton’s law

Q18. The mass of one C atom is:
6.023 `\times 10^{23}`
1.99 `\times 10^{-23}`
2.00 g
12 g

Q19. The chemical symbol for barium is:
B
Ba
Be
Bi

Q20. The chemical symbol P stands for:
Phosphorus
Potassium
Polonium
Promethium


Set 1 Set 2 set 3 Set 4 Set 5
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