Correct Answer: A. sulfuric acid

Explanation

The contact process is used for the industrial production of sulfuric acid, not any of the options provided. The process involves the oxidation of sulfur dioxide to sulfur trioxide which is then absorbed in sulfuric acid to form oleum. The oleum is then diluted with water to form sulfuric acid.

Correct Answer: A) hex-3-ene

Correct Answer: A. Cryolite

Correct Answer: D. decreasing the activation energy of the reaction

Correct Answer: D) X-rays

Explanation

(a)(i) Quantum numbers assigned to an electron in an atom are

9(i) n - (principal) quantum number

(ii) L - (azimuthal) sub principal quantum number

(iii) m - (magnetic quantum number) and (iv) s - (spin quantum number)

(ii) The maximum number of electrons that can occupy the 3d orbital is 10.

(b) The element p represented by the electronic configuration 1s\(^2\)s\(^2\)2p\(^6\)3s\(^2\)

(i) The electronic configuration of its ions is 1s\(^2\)2s\(^2\)2p\(^6\) Most likely formula of the chloride of P is PCl\(^2\)

(iii) P is a good reducing agent. Reducing agents are electron donors OR P would readily lose 2(two) electrons to form noble gas structure.

(c)(i) Electron affinity is defined as the energy evolved or liberated when 1 mole of an element in form of gaseous atoms form negative ions OR The energy liberated or absorbed when one mole of electron is added to an element in form of gaseous atoms.

(ii) Ammonia can participate in dative bonding because dative bonding involves the sharing of an electron pair donated by one atom. The nitrogen in ammonia has a lone pair of electrons which can be donated for sharing.

(d)(i) if an element in group IV loses an alpha particle, the product would belong to group II.

(ii) Since both X and Y are equally toxic, Y constitutes a greater health hazard than X which has a shorter half life because half life is the time taken to decay to half the initial value remains for a longer period in the body and being toxic causes damage for a longer period.

Explanation

(a)(i) A labelled diagram for the laboratory preparation of a dry, sample of sulphur (iv) oxide.

(Any one situable but must correspond to reactants in the diagram)

(ii) Balanced chemical equation for the reaction in 4(a)(i)

NaSO\(_{3(aq)}\) + 2HCl\(_{(aq)}\) —> 2NaCl\(_{3(aq)}\) H2O\(_{(l)}\) + SO\(_{2(g)}\)

OR

K\(_{2}\)SO\(_{3(aq)}\) + 2HCl\(_{(aq)}\) —> H\(_2\)O\(_{l}\) + SO\(_{2(g)}\)

OR

NaSO\(_{3(aq)}\) + H\(_2\)SO\(_{4(aq)}\) —> 2Na\(_{2}\)SO\(_4\) + H\(_2\)O\(_{(l)}\) + SO\(_{2(g)}\)

(iii) Precaution in the preparation of the gas in 4(a)(i). The gas should be prepared in a fume cupboard (chamber).

(iv) Reason for the precaution. It is because the gas is poisonous.

(b)(i) Dalton's law of partial pressures states that for a mixture of gases which do not react, the total pressure is equal to the sum of the partial pressures of the individual gases.

(ii) Volume of methane (CH\(_4\)) collected over water at temperature of 12°C and a pressure of 700mmHg was 30cm\(_3\).

Volume of the gas (dry) at s.t.p.

\(\frac{P_1V_1}{T_1} = \frac{P_2 V_2}{T_2}\)

\(P_1\) = (700 — 10) = 690 mmHg (dry gas)

\(T_1\) = 12 + 273 = 285 K

\(V_2\) = \(\frac{P_1V_1T_2}{P_2T_1}\)

P\(_2\) = 760mmHg, T\(_2\) = 273k

\(V_2\) = \(\frac{690 \times 30 \times 273}{760 \times 285}\)

\(V_2\) = 26.09cm\(^3\)

\(V_2\) = 26.10cm\(^3\)

(c)(i) Equation for the reaction between chlorine and water. Cl\(_{2(g)}\) + H\(_2\)O \(\to\) HCI + HCIO

(ii) Litmus paper turned red (from blue to red) because H\(^+\) ions are released or HCI produced is acidic. Also HCIO produced is acidic too. The solution is acidic.

(d)(i) Trend in the boiling points of chlorine, bromine and iodine. Boiling point of iodine is greater than that of bromine which is greater than that of chlorine. Boiling point increases from chlorine to iodine.

(ii) Water has a higher boiling point than ammonia because water has stronger hydrogen bonds than ammonia. Also because oxygen atom has two lone pairs of electrons and nitrogen atom has one pair of electron. Also oxygen is more electronegative than nitrogen.

Correct Answer: A) ionic bonding

Explanation

Bond dissociation energy refers to the amount of energy required to break a bond between two atoms. The higher the bond dissociation energy, the stronger the bond.

The options given are ionic bonding, covalent bonding, hydrogen bonding, metallic bonding, and van-der-waals bonding.

The correct answer is Option A, which is ionic bonding. Ionic bonding involves the transfer of electrons from one atom to another, resulting in positively-charged cations and negatively-charged anions that are held together by electrostatic attractions. These attractions are very strong, hence the high bond dissociation energy of 500 KJ mol-1 can be assigned to ionic bonding.

Covalent bonding involves the sharing of electrons between atoms, while hydrogen bonding involves a special type of dipole-dipole interaction between molecules containing hydrogen and electronegative elements. Metallic bonding involves the sharing of electrons between metal atoms, while van-der-waals bonding involves weak intermolecular forces between nonpolar molecules.

To learn more about chemical bonding and bond dissociation energy, please see the relevant sections of the recommended textbooks

Correct Answer: B. + 4 to + 6

Correct Answer: A) hydrate iron (III) oxide