Physical and Chemical Properties of Hydrogen

Q.

Complete and balance the reaction :

$\mathrm{Ca}+{\mathrm{H}}_2\mathrm{O}\to$

Q.

Give the information conveyed by the following information:

Zn + 2HCl $\to$ ZnCl₂ + H₂

Q.

The bond order of ${\mathrm{B}}_2$ molecule is_______?

Q. 33. CN is a strong field ligand. This is due to the fact that :- (1) It is a pseudohalide (2) It can accept electrons from metal species (3) It forms high spin complexes with metal species (4) It carries negative charge

Q.

Is nitrogen an inert gas?

Q.

Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions?

Q.

What is the oxidation state of p in ph3

Q.

Why ${\mathrm{AlCl}}_3$ does not show back bonding?

Q. Nascent hydrogen consists of:

1. Hydrogen ions in excited state
2. Hydrogen ions with excess energy
3. Solvated protons
4. Hydrogen atoms with excess energy

Q. Would you expect benzaldehyde to be more reactive or less reactive in nucleophilic addition reactions than propanal? Explain your answer.

Q.

The decreasing order of reactivity of different forms of hydrogen is:

1. Atomic hydrogen = Nascent hydrogen > Molecular Hydrogen

2. Nascent hydrogen > Atomic hydrogen > Molecular hydrogen

3. Atomic hydrogen > Nascent Hydrogen > Molecular Hydrogen

4. Molecular Hydrogen > Atomic Hydrogen = Nascent Hydrogen

Q. Between cuprous and cupric which is more stable and why

Q.

Is hydrogen gas flammable?

Q.

How do you Calculate Enthalpy of Hydrogenation ?

Q.

State the trend in chemical reactivity :

(i) across the period left to right

Q.

How can rancidity of fats and oils be prevented?

Q.

Hydrogen is heavier than air and readily soluble in water.

1. True
2. False

Q.

The litmus solution when shaken with charcoal becomes colorless. Explain

Q.

The head of a safety match contains-

1. Antimony trisulphide and potassium chlorate

2. Antimony chloride and potassium sulphide

3. Antimony carbonate

4. Potassium sulphide

Q. Which of the following does not occur during the process of charging a lead storage battery

1. Increase in concentration of electrolyte
2. Increase in relative density of electrolyte
3. Conversion of $PbS{O}_4$ to $Pb$ and $PbO$
4. Decrease in relative density of electrolyte

Q.

Explain why alkali and alkaline earth metals cannot be obtained by chemical reduction methods?

Q. The correct order of increasing $C-X$ bond length is:
($R$ is methyl group)

1. $RI>RBr>RCl>RF$
2. $RF>RCI>RBr>RI$
3. $RBr>RCl>RI>RF$
4. $RCl>RF>RI>RBr$

Q. Which of the following is not a chalcogen?

1. $Se$
2. $O$
3. $S$
4. $Na$

Q.

Give reason:

Liquid ammonia is used as a refrigerant.

Q.

Question 2

Why does $H^{+}$ ion always get associated with other atom or molecules?

(a) Ionisation enthalpy of hydrogen resembles that of alkali metals.

(b) Its reactivity is similar to halogens

(c) It resembles both alkali metals and halogens

(d) Loss of an electron from hydrogen atom results in a nucleus of very small size as compare to other or ions. Due to small size it cannot exist free.

Q. Electrolysis of $NaCl\left(aq\right)$ is carried out using inert electrodes, choose the correct option(s):

1. When concentrated $NaCl$ is used, oxygen gas is liberated at anode.
2. When dilute $NaCl$ is used, chlorine gas is liberated at anode.
3. When concentrated $NaCl$ is used, chlorine gas is liberated at anode.
4. When dilute $NaCl$ is used, oxygen gas is liberated at anode.

Q.

Nascent Hydrogen consists of ______

Q.

A gas that extinguishes the glowing splinter?

Q.

A mixture of carbon monoxide and hydrogen

Q. A dilute aqueous solution of $N{a}_{2}S{O}_4$ is electrolysed using platinum electrodes. The products at the anode and cathode are:

1. $O_2,H_2$
2. $S_2{O}_8^{2-},Na$
3. $O_2,Na$
4. $S_2{O}_8^{2-},H_2$