#### Public exam five mark questions in Basic Concepts of Chemistry and Chemical Calculations

11th Standard

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Chemistry

Time : 01:40:00 Hrs
Total Marks : 100

Part - A

20 x 5 = 100
1. Write note on combination reaction.

2. Write note on decomposition reaction

3. Explain displacement reaction.

4. What are disproportionation reaction?

5. Arrange the elements silver, Zinc and copper in the order of their decreasing electron releasing tendency and justify your arrangement with an appropriate experiment.

6. Distinguish between the following.
(i) Atomic and molecular mass
(ii) Atomic mass and atomic weight
(iii) Empirical and molecular formula
(iv) Moles and molecules.

7. In a reaction, A + B2 $\longrightarrow$ AB2, identify the limiting reagent if any in the following reaction mixtures
(i) 300 atoms of A + 200 molecules of B
(ii) 2 moles of A + 3 moles of B
(iii) 100 atoms of A + 100 molecules of B
(iv) 5 moles of A + 2.5 moles of B
(v) 2.5 moles of A + 5 moles of B

8. Explain the term competitive electron transfer reaction with an example.

9. Balance the following equations by oxidation number method.
CuO + NH3 ⟶ Cu +N2 + H2O

10. Balance the following equations by oxidation number method.
P + HNO3 ⟶ HPO3 + NO + H2O

11. Balance the following equations by oxidation number method.
KIO3 + SO2 + H2O ⟶ KHSO4 + H2SO4 + I2

12. Balance the following equations by oxidation number method.
C6H12O6 + H2SO4 ⟶ CO2 + SO2 + H2O

13. Balance the following equations by oxidation number method.
C4H10 + O2 ⟶ CO2 + H2O

14. Balance the following equations by oxidation number method.
NH3 + F2 ⟶ HF + N2

15. Balance the following equations by oxidation number method.
K2Cr2O7 + HI ⟶ KI + Crl3 + H2O + I2

16. Balance the following equations by oxidation number method.
Zn + HNO3 ⟶ Zn(NO3)2 + N2O + H2O

17. Balance the following equations by oxidation number method.
Ag + HNO3 ⟶ AgNO3 + H2O + NO

18. Balance the following equations by oxidation number method.
K2Cr2O7 + FeSO4 + H2SO4 ⟶ K2SO4 + Cr2(SO4)3 + Fe2(SO4)3 + H2O

19. Balance the following equations by oxidation number method.
KBr + MnO2 + H2SO4 ⟶ KHSO4 + MnSO4 + H2O + Br2

20. Balance the following equations by oxidation number method.
KMnO4 + KOH + H2O2 ⟶ K2MnO4 + O2 + H2O

21. An inorganic compound an analysis gave the following composition. Na = 14.31%, S = 9.97%, H = 6.22%, O = 69.5%. Assume all the hydrogen atoms are present in combination with oxygen as water of crystallization. The molar mass of the compound is 322 g mol-1. Find its molecular formula.

22. Calculate the number of molecules of oxygen gas that occupies a volume of 224 rot at 273K.at 3 atm.

23. Balance the following equation by ion electron method.
Cr2O72- + Fe2+ ⟶ Cr3+ + Fe2+ in acidic medium.

24. Balance the following equation by ion electron method.
Cr2O72-+C2H4O ⟶ Cr+3 + C2H4O2

25. Balance the following equation by ion electron method.
Zn + NO3- ⟶ Zn + NH4+2