Oxidation States

Q.

What is the oxidation number of chlorine? Explain with examples.

Q.

What is the oxidation number of nitrogen in ${\mathrm{NO}}_2$?

Q. Which of the following is correct regarding oxidation states of \oxygen and fluorine in $O{F}_2\&O_2{F}_2$?

1. Oxidation state of fluorine is -1 in both the compounds.
2. Oxidation state of oxygen is +1 in $O_2{F}_2$
3. Oxidation state of oxygen is +2 in $O{F}_2$
4. All of the above.

Q. The difference in oxidation state of $Cl$ atom in $HCl{O}_4$ and $HCl{O}_3$ respectively is:

1. 0
2. 1
3. 2
4. 3

Q. Air contains 20 percent O2 by volume. How many cc of air will be required for oxidation of 100 cc of acetylene.

Q.

Define covalency.

Q.

Why is manganese dioxide used as a catalyst in the laboratory for preparation of oxygen?

Q. Fluorine exhibits only $-1$ oxidation state whereas other halogens exhibit $+1,+3,+5\text{and}+7$ oxidation states also. Explain.

Q. If the atomic number of an element is $33$, it will be placed in the periodic table in the:

1. First group
2. Third group
3. Fifteenth group
4. Seventeenth group

Q.

What is the oxidation state of H in PH₃?

Q. Orange solution of potassium dichromate turns yellow on adding sodium hydroxide to it. Give reason.

Q.

6. Explain why-carbon dioxide is collected by the upward displacement of air?

Q. The oxidation state of $Cl$ in $C{l}_2{O}_7$ is:

1. $+7$
2. $+5$
3. $+3$
4. $-7$

Q.

Electrovalent compounds have ______ (high/low) melting points.

Q.

How does the oxidation number of oxygen changes when oxygen reacts with fluorine

Q.

Electrovalent compounds have a _____ (low/high) boiling point.

Q.

What are the rules for finding oxidation number?

Q.

The atomic number of magnesium is 12 and of chlorine is 17. Show the formation of magnesium chloride by the transfer of electrons ${\mathrm{Mg}}^{+2}$.

Q. Compound ‘A’ was prepared by the oxidation of compound ‘B’ with alkaline $KMn{O}_4$. Compound ‘A’ on reduction with lithium aluminium hydride gives compound ‘B’. When compound ‘A’ is heated with compound ′B′ in the presence of $H_{2}S{O}_4$ it produces a fruity-smelling of compound ′C′. To which family do the compounds ‘A’, ‘B’ and ‘C’ belong?

Q.

Is a catalyst consumed in reaction?

Q. The oxide containing chlorine in the highest oxidation state is

1. 
2. 
3. 
4. 

Q.

Why do the metal oxide having more oxidation number more acidic

Q.

What is the use of manganese dioxide in the laboratory preparation of oxygen gas?

Q.

Is phenyl used for disinfection of drinking water?

Q.

What is Oxidation state of Fe inside and outside in Fe4[Fe(CN)6]

Q.

Difference between primary and daughters secondary valency

Q. Elements of which of the following groups will form anions most readily?

1. Alakali metals
2. Oxygen family
3. Nitrogen family
4. Halogens

Q.

Generally, transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid state?

1. $Cu{F}_2$
2. $C{u}_{2}C{l}_2$
3. $A{g}_{2}S{O}_4$
4. $Zn{F}_2$

Q. Electronic configuration of $F{e}^{3+}$ ion is

Q. Explain why Maximum covalency of nitrogen is four.