Reactivity Towards Air

Q. Which of the following has the highest $p\pi -p\pi$ bonding tendency?

1. $N$
2. $P$
3. $As$
4. $Sb$

Q. The bond order of carbonyl $(C-O)$ bond after back-bonding:

1. Increases.
2. Decreases.
3. Remains constant.
4. Cannot be predicted.

Q.

Water-gas is a mixture of equal volumes of hydrogen and water vapor.

1. True
2. False

Q. Water gas is the mixture of which gas?
(P) Carbon dioxide
(Q) Hydrogen
(R) Carbon monoxide

1. P and Q
2. Q and R
3. P and R
4. P, Q and R

Q. Which among the following is strongest oxidising agent?

1. $Pb{O}_2$
2. $Sn{O}_2$
3. $Ge{O}_2$
4. $Si{O}_2$

Q. Name of the group-16 element which shows maximum catenation.

1. Sulphur
2. Oxygen
3. Selenium
4. Tellurium

Q. All members of group 14 when heated n in oxygen form oxides. Which of the following is the correct trend of oxides?

1. Dioxides $C{O}_2,Si{O}_2$ and $Ge{O}_2$ are acidic while $Sn{O}_2$ and $Pb{O}_2$ are amphoteric.
2. Monoxides react with haemoglobin to form toxic compounds.
3. All oxides burn with blue flame.
4. CO, GeO, SnO and PbO are amphoteric.

Q.

Carbon forms a large number of compounds due to:

1. Tetravalency

2. Variable valency

3. Large chemical affinity

4. Property of catenation

Q. Match the column I with column II and mark the appropriate choice.

	Column I		Column II
(A)	Coal gas	(i)	$CO+H_2$
(B)	Synthesis gas	(ii)	$C{H}_4$
(C)	Producer gas	(iiii)	$H_2+C{H}_4+CO$
(D)	Natural gas	(iv)	$CO+N_2$

1. $\left(A\right)\to \left(i\right),\left(B\right)\to \left(ii\right),\left(C\right)\to \left(iii\right),\left(D\right)\to \left(iv\right)$
2. $\left(A\right)\to \left(i\right),\left(B\right)\to \left(iii\right),\left(C\right)\to \left(ii\right),\left(D\right)\to \left(iv\right)$
3. $\left(A\right)\to \left(iv\right),\left(B\right)\to \left(iii\right),\left(C\right)\to \left(ii\right),\left(D\right)\to \left(i\right)$
4. $\left(A\right)\to \left(iii\right),\left(B\right)\to \left(i\right),\left(C\right)\to \left(iv\right),\left(D\right)\to \left(ii\right)$

Q. Pb${}_3$O${}_4$ is regarded as a mixed oxide of PbO and PbO${}_2$. How many parts of PbO${}_2$ are present in it?

Q. Identify the group $14A$ element that best fits each of the following descriptions:

1. (a)$Pb$; (b)$C$; (c)$Si$; (d)$C$
2. (a)$Pb$; (b)$C$; (c)$Pb$; (d)$C$
3. (a)$Pb$; (b)$C$; (c)$Si$; (d)$Si$
4. (a)$Sn$; (b)$C$; (c)$Si$; (d)$C$

Q. Write the chemical equations of the reactions involved in solvay process of preparation of sodium carbonate.

Q. Each molecule of inert gases is diatomic.

1. True
2. False

Q. The oxide which is strongest acid is:

1. $T{l}_2{O}_3$
2. $Pb{O}_2$
3. $Sn{O}_2$
4. $C{O}_2$

Q. A metal carbonate $X$ on treatment with a mineral acid liberates a gas which when passed through an aqueous solution of a substance $Y$ gives back $X$. The substance $Y$ on reaction with the gas obtained at the anode during electrolysis of brine gives a compound $Z$ which can decolourise coloured fabrics. The compounds $X,Y$ and $Z$ respectively are:

1. $CaC{O}_3,Ca(OH{)}_2,CaOC{l}_2$
2. $Ca(OH{)}_2,CaO,CaOCl,$
3. $Ca(OH{)}_2,CaC{O}_3,CaOC{l}_2$
4. $CaC{O}_3,CaOC{l}_2,Ca(OH{)}_2$

Q. Red lead $\left(P{b}_3{O}_4\right)$ reacts with conc. $HCl$ and conc. $H_{2}S{O}_4$ separately liberating _________ and _________ gases respectively.

1. $C{l}_2,O_2$
2. $H_2,O_2$
3. $O_2,S{O}_2$
4. $C{l}_2,S{O}_2$

Q. Choose the correct statement among the following.

1. When the match is struck against the rubbing surface, some red phosphorous gets converted into white phosphorous.
2. The job of a fire extinguisher is to cut off the supply of carbon dioxide, and hence the fire is controlled.
3. The substances which vapourise during burning, do not give flames.
4. The substances which have very high ignition temperature are called inflammable substances.

Q. Hydrocarbons are burnt in air to produce:

1. carbon dioxide
2. ozone
3. carbon
4. water

Q.

Carbon forms a large number of compounds due to:

1. Variable valency

2. Large chemical affinity

3. Tetravalency

4. Property of catenation