Valence, oxidation states and chemical reactivity — practice questions

Question 1 · difficulty L2 · understanding

The correct set that contains all kinds (basic, acidic, amphoteric and neutral) of oxides is :

• A. Na 2 O, K 2 O, Al 2 O 3 and As 2 O 3
• B. Al 2 O 3 , As 2 O 3 , CO and NO
• C. K 2 O, Cl 2 O 7 , As 2 O 3 and NO
• D. Na 2 O, N 2 O, Al 2 O 3 and CO

Question 2 · difficulty L2 · understanding

Given below are two statements : Statement (I) : An element in the extreme left of the periodic table forms acidic oxides. Statement (II) : Acid is formed during the reaction between water and oxide of a reactive element present in the extreme right of the periodic table. In the light of the above statements, choose the correct answer from the options given below :

• A. Both Statement I and Statement II are false
• B. Both Statement I and Statement II are true
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Question 3 · difficulty L2 · understanding

Given below are two statements: Statement - I: Along the period, the chemical reactivity of the elements gradually increases from group 1 to group 18 . Statement - II: The nature of oxides formed by group 1 elements is basic while that of group 17 elements is acidic. In the light of the above statements, choose the most appropriate from the options given below:

• A. Statement I is False but Statement II is true
• B. Both Statement I and Statement II are False
• C. Statement I is True But Statement II is False
• D. Both Statement I and Statement II are True

Question 4 · difficulty L2 · understanding

Group-13 elements react with $$\mathrm{O}_{2}$$ in amorphous form to form oxides of type $$\mathrm{M}_{2} \mathrm{O}_{3}~(\mathrm{M}=$$ element). Which among the following is the most basic oxide?

• A. Al$$_2$$O$$_3$$
• B. TI$$_2$$O$$_3$$
• C. B$$_2$$O$$_3$$
• D. Ga$$_2$$O$$_3$$

Question 5 · difficulty L2 · understanding

Match List - I with List - II : List-I (Oxide) List-II (Nature) (A) $$C{l_2}{O_7}$$ (I) Amphoteric (B) $$N{a_2}O$$ (II) Basic (C) $$A{l_2}{O_3}$$ (III) Neutral (D) $${N_2}O$$ (IV) Acidic Choose the correct answer from the options given below :

• A. (A) - (IV), (B) - (III), (C) - (I), (D) - (II)
• B. (A) - (IV), (B) - (II), (C) - (I), (D) - (III)
• C. (A) - (II), (B) - (IV), (C) - (III), (D) - (I)
• D. (A) - (I), (B) - (II), (C) - (III), (D) - (IV)

Question 6 · difficulty L2 · understanding

Among the following, basic oxide is :

• A. SO 3
• B. SiO 2
• C. CaO
• D. Al 2 O 3

Question 7 · difficulty L2 · understanding

Given below are the oxides: Na 2 O, As 2 O 3 , N 2 O, NO and Cl 2 O 7 Number of amphoteric oxides is :

• A. 0
• B. 1
• C. 2
• D. 3

Question 8 · difficulty L2 · understanding

Match List - I with List - II : List - I List - II (a) NaOH (i) Acidic (b) $$Be{(OH)_2}$$ (ii) Basic (c) $$Ca{(OH)_2}$$ (iii) Amphoteric (d) $$B{(OH)_3}$$ (e) $$Al{(OH)_3}$$ Choose the most appropriate answer from the options given below

• A. (a)-(ii), (b)-(ii), (c)-(iii), (d)-(ii), (e)-(iii)
• B. (a)-(ii), (b)-(iii), (c)-(ii), (d)-(i), (e)-(iii)
• C. (a)-(ii), (b)-(ii), (c)-(iii), (d)-(i), (e)-(iii)
• D. (a)-(ii), (b)-(i), (c)-(ii), (d)-(iii), (e)-(iii)

Question 9 · difficulty L2 · understanding

Which pair of oxides is acidic in nature?

• A. CaO, SiO 2
• B. B 2 O 3 , CaO
• C. B 2 O 3 , SiO 2
• D. N 2 O, BaO

Question 10 · difficulty L2 · understanding

Total number of acidic oxides among $$\mathrm{N_2O_3,NO_2,N_2O,Cl_2O_7,SO_2,CO,CaO,Na_2O}$$ and $$\mathrm{NO}$$ is ____________.