Valency and Oxidation States

Q. The oxidation state of nitrogen varies from:

1. $-3$ to $+5$
2. $0$ to $+5$
3. $-3$ to $1$
4. $+3$ to $+5$

Q.

Why do alkali metals have low ionization energy?

Q.

What is the electron configuration of an $\mathrm{Mn}$ atom in the ground state?

Q.

Name two elements you would expect to show chemical reactions similar to Magnesium. What is the basis of your choice?

Q.

What is the ground-state electron configuration of $\mathrm{Pb}$?

Q. The number of valence electrons in the elements A and B are 3 and 6 respectively. The most probable compound formed from A and B is:

1. $A_{2}B$
2. $A{B}_2$
3. $A_2{B}_3$
4. $A_6{B}_3$

Q.

Elements of group 14

(a) exhibit oxidation state of +4 only

(b) exhibit oxidation state of +2 and +4

(c) form $M^{2–}$ and $M^{4+}$ ion

(d) form $M^{2+}$ and $M^{4+}$ ions

Q.

What is Group 11 called?

Q.

an Alkoxide ion is a stronger base than a hydroxide ion. Why?

Q.

Difference between valency , covalency , and oxidation state

Q. What is the magnetic moment of $K_3\left[Fe{F}_6\right]$

1. 5.91 B.M.
2. 4.89 B.M.
3. 3.87 B.M.
4. 6.92 B.M.

Q.

Compare the chemistry of actinoids with that of the lanthanoids with special reference to:

(i) electronic configuration (iii) oxidation state

(ii) atomic and ionic sizes and (iv) chemical reactivity.

Q.

The most common oxidation state of an element is -2. The number of electrons present in its outermost shell is:

Q. Which of the following compounds contain phosphorus with an oxidation state of $+5$?

1. Pyrophosphoric acid
2. Hypophosphorous acid
3. Orthophosphorous acid
4. Hypophosphoric acid

Q. Which metal exhibits more than one oxidation states in their compounds.

1. $Na$
2. $Fe$
3. $Mg$
4. $Al$

Q. A solution of $N{a}_2{S}_2{O}_3$ is standarised iodometrically against $0.167$ gram of $KBr{O}_3$. This process requires $50\text{mL}$ of the $N{a}_2{S}_2{O}_3$ solution. What would be the normality of the $N{a}_2{S}_2{O}_3$ solution?
(Molar mass of $KBr{O}_3$ is $167\text{g/mol}$)

1. $0.2\text{N}$
2. $0.02\text{N}$
3. $0.12\text{N}$
4. $0.72\text{N}$

Q. Statement I $P{b}^{4+}$ compounds are stronger oxidising agents than $S{n}^{4+}$ compounds.
Statement II The higher oxidation states for the group 14 elements are more stable for the heavier members of the group due to 'inert pair effect'.(J2008, 3M)

1. Statement I is true; Statement II is true; Statement II is the correct explanation of Statement I.
2. Statement I is true; Statement II is true; Statement II is not the correct explanation of Statement I.
3. Statement I is true; Statement II is false.
4. Statement I is false; Statement II is true.

Q.

The chemistry of the actinoid elements is not so smooth as that of the Lanthanoids. Justify this statement by giving some examples from the oxidation state of these elements.

Q.

Where would you locate the element with electronic configuration 2, 8 in the Modern Periodic Table?

1. Group 8

2. Group 2

3. Group 18

4. Group 10

Q. An element with mass number 81 contains 31.7% more neutrons as compared to protons. Find the symbol of the atom.

1. ${}_{34}^{81}Se$
2. ${}_{35}^{81}Br$
3. ${}_{36}^{81}Kr$
4. ${}_{37}^{81}Rb$

Q.

What is the no of unpaired electrons and sum of spin of Gd

Q.

Which is more ionic $\mathrm{NaCl}\mathrm{or}{\mathrm{AlCl}}_3$?

Q.

In ${\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}$ what are their secondary valency and the number of hydrogen bonds?

1. $6\mathrm{and}4$

2. $4\mathrm{and}1$

3. $5\mathrm{and}1$

4. $6\mathrm{and}5$

Q. Group 14 elements exhibit +2 and +4 oxidation states, +2 oxidation state is more stable than +4 in case of

1. C
2. Pb
3. Sn
4. Si

Q.

What is the difference between oxygen and oxide?

Q.

The number of electrons lost, gained or shared by an atom of an element is known as ………………………

Q.

Suggest a list of the substances where carbon can exhibit oxidation states from –4 to +4 and nitrogen from –3 to +5.

Q.

Which among the following Xe compounds is highly explosive and a powerful oxidising agent ?

1. XeO₃

2. XeOF₄

3. XeF₄

4. XeF₂

Q. The species that contains 24 protons, 26 neutrons and 22 electrons would be represented by the symbol:

1. ${}^{50}{V}^{3+}$
2. ${}^{26}C{r}^{2+}$
3. ${}^{50}C{r}^{2+}$
4. ${}^{26}M{n}^{2+}$

Q.

Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?
(a) Valence principal quantum number (n)
(b) Nuclear charge (Z)
(c) Nuclear mass
(d) Number of core electrons.