Correct Answer: A. ethanol

Correct Answer: C. Do a chromatogram of the colouring extract

Correct Answer: B. increases the solubility of a solid in a liquid but decreases the solubility of a gas in a liquid.

Explanation

-The solubility of gases in liquids decreases with increasing temperature. Conversely, adding heat to the solution provides thermal energy that overcomes the attractive forces between the gas and the solvent molecules, thereby decreasing the solubility of the gas -The solubility of most solid or liquid solutes increases with increasing temperature

Correct Answer: C) hydrogen bonding

Explanation

(a) i) Temporary hardness and permanent hardness.

(ii) Temporary hardness

— Calcium hydrogen rioxocarbonate IV or magnesium hydrogentrioxocarbonate(IV). Permanent hardness

— Calcium etraoxosulphate (VI) or magnesium tetraoxosulphate (VI).

Temporary hardness:

iii) Ca(HCO\(_3\))\(_2\) + Ca(OH)\(_2\) \(\to\) 2CaCO\(_3\) + H\(_2\)O

OR Ca(HCO\(_3\))\(_2\) \(\to\) CaCO\(_3\) + H\(_2\)O + CO\(_2\)

Permanent hardness: CaSO\(_4\) + Na\(_2\)CO\(_3\) \(\to\) CaCO\(_3\) + Na\(_2\)SO\(_4\)

(iv) It forms precipitate of calcium salt or ;cum with soap that waste soap.

(b)(i) 1. Glucose solution —Equal to 7

II. Chlorine water — Less than 7

II. Lime water — Greater than 7

IV. Sour milk — Less than milk.

(ii) I. An acidic oxide reacts with only alkali to form salt and water only while amphoteric oxide react with both acids and alkalis to form salt and water only.

II. A dilute acid contains more water than a concentrated acid.

III. An acid salt contains replacement iydrcgen while a normal salt does not.

(c)(i) Fe\(_{(S)}\) + H\(_2\)SO\(_{4(aq)}\) \(\to\) FeSO\(_{4(aq)}\) + H\(_{2(g)}\) ;

Molar mass of FeSO\(_4\) 56 + 32 + 64 = 152

1 mole of Fe produces 152 mass of FeSO\(_4\) ;

0.5 mole of Fe will produce \(\frac{0.5 \times 152}{1}\) = 76g

ii) Monoclinic and rhombic sulphur

(d)(i) When a piece of damp starch - iodide paper is plunged in a gas ar of chlorine, the paper turns from white to blue or blue black.

(ii) Chlorine displaces iodine from starch odide. The iodine reacts with starch to form a blue black complex.

(iii) Products formed are hydrogen Chloride and nitrogen.

Explanation

(a) The type of process involved in the reaction is called dehydration

(b) The basicity of the acid is 2

(c)

Explanation

(a)(i) Loss of mass in anode = 7.20 – 4 = 3.20g

Mass of cathode after the experiment = 5.75 + 3.20

= 8,95g.

(ii) I. Anode : Cu \(\to\) Cu\(^{2+}\) + 2e\(^-\)

II. Cathode : Cu\(^{2+}\) + 2e\(^-\) \(\to\) Cu

(iii) Colour of solution does not change because copper ions discharged at the cathode are replaced by copper ion (Cu\(^{2+}\)) produced at the anode.

(iv) 1 mole Cu = 2F mole of Cu deposited = \(\frac{3.2}{63.5}\) = 0.05

number of Faradays used = 0.05 x 2 = 0.1F

Quantity of electricity used = 80 x 60 x 2 = 9600C

9600 = 0.1F

F = \(\frac{9600}{0.1}\) = 96000C

(b) MnO\(^-_4\) + 1\(^-\) + H\(^+\) \(\to\) I\(_2\) + H\(_2\)O + Mn\(^{(2+)}\)

(i) 2\(^-\) - 2e \(\to\) I\(_2\) (oxidation).

(ii) MnO\(^-_4\) + 8H\(^+\) + 5e\(^-\) \(\to\) Mn\(^{(2+)}\) + 4H\(_2\)O (reduction)

(c)(i) Tin ore (SnO\(_2\)) or casseterite is crushed and washed with water. It is roasted in air, the product is mixed with powdered charcoal and heated strongly at about 1300°C to obtain molten tin.

(ii) Uses of tin: (1) It is used for making alloys (2) It is used for coating steel or for tin plating (electroplating).

(iii) Corresponding property: (1) It has high tensile strength, lightness (2) It is non-toxic, non-corrosive, inert and unreactive.

(d)(i) Pollution is the contamination of the environment by substances in concentrations that can cause injur, to lives and property.

(ii) It is dangerous to run a generator in a room because the carbon (II) oxide released from the exhaust combines with blood, leading to blood poisoning which can result to death.

Correct Answer: D. NaCI

Correct Answer: B. KCIO₃

Correct Answer: C) both reactants and products

Explanation

The given reaction is:

2CO(g) + O\(_2\)(g) \(\iff\) 2CO\(_2\)(g)

This reaction is at equilibrium, which means that the rate of the forward reaction (formation of CO\(_2\) is equal to the rate of the reverse reaction (formation of CO and O\(_2\).

According to Le Chatelier's principle, when a system at equilibrium is subjected to stress (such as change in pressure, temperature, or concentration), the system will adjust itself in order to partially counteract the applied stress and restore a new equilibrium.

In this case, when the reaction is subjected to stress, the system will try to counteract the stress by shifting the equilibrium position either to the right (favoring the forward reaction) or to the left (favoring the reverse reaction). This shifting will cause a change in the concentration of both reactants (CO and O\(_2\) and products (CO\(_2\).

Therefore, the correct answer isOption C: both reactants and products, as their concentrations will change when the system tries to restore equilibrium after being subjected to stress.