Correct Answer: C) 2-Methylpropan-1-ol

Explanation

It cannot be butan-1-ol since the acid is branched rather than straight chained. Rather, the answer should be 2-Methylpropan-1-ol since the acid has its functional group at the end.

Correct Answer: C. Bromine

Correct Answer: B. helium

Explanation

(a) If R, S and T respectively are an alkene, alkene and a terminal alkyne:

(i) S and T would undergo addition reaction.

(ii) k, S and T would undergo combustion.

(iii) R and T would undergo substitution.

(b)(i) An alkanol is converted into an alkene by dehydration.

(ii) The third member of the alkanol series is propanol or propan - 2 - ol.

(c)(i) Chemical test for alkanoic acid: Add (saturated) NaHCO\(^{3}\) or Na\(_2\)CO\(_3\)(solution), effervescence or gas evolved indicating alkanoic acid.

(ii) The reaction of methanoic acid with ethanol in the presence of mineral acid.

Equation: HCOOH + CH\(_3\)CH\(_2\)OH —> HCOOC\(_2\)H\(_5\) + H\(_2\)O

(iii) Role of mineral acid in (ii) above, is catalysis or acts as catalyst

(d) Cassava was pressure-cooked, then malt was added at 55°C for 2 hours followed by yeast. After 2 days at 27`C an organic product J and gas H were obtained

(i) H was CO\(_2\).

(ii) Starch is polysaccharide / complex carbohydrate. During treatment with malt, it was hydrolysed by diastascgcmylase Diastase

in malt to sugar / maltose.

(C\(_6\)H\(_{10}\)O\(_5\))n + nH\(_2\)O --> \(_n\)C\(_12\)H\(_{22}\)O\(_{11}\)

Correct Answer: C) 56 and 139

Explanation

The given nuclear reaction is:

\(^{235}_{92}U + ^1_0n \rightarrow ^{94}_{36}Kr + Ba + 3^1_0n\)

When a slow-moving neutron bombards Uranium-235, it undergoes nuclear fission, producing Krypton-94 and Barium (Ba) as well as releasing three more neutrons. To find the atomic number and mass of Barium, we need to apply the law of conservation of mass and atomic number in nuclear reactions.

The law of conservation of mass states that the sum of the masses on the left side of the equation must be equal to the sum of the masses on the right side. Similarly, the law of conservation of atomic number states that the sum of the atomic numbers on the left side of the equation must be equal to the sum of the atomic numbers on the right side.

Let's first find the atomic number of Barium:

On the left side, we have Uranium with an atomic number of 92 and a neutron with an atomic number of 0, giving a total atomic number of 92. On the right side, we have Krypton with an atomic number of 36, and Barium with an unknown atomic number. So, we can write:

\(92 = 36 + Z_{Ba}\)

Solving for the atomic number of Barium, we get:

\(Z_{Ba} = 92 - 36 = 56\)

Now let's find the mass of Barium:

On the left side, we have Uranium with a mass of 235 and a neutron with a mass of 1, giving a total mass of 236. On the right side, we have Krypton with a mass of 94, Barium with an unknown mass, and three neutrons each with a mass of 1, giving a total mass of \(94 + A_{Ba} + 3\). So, we can write:

\(236 = 94 + A_{Ba} + 3\)

Solving for the mass of Barium, we get:

\(A_{Ba} = 236 - 94 - 3 = 139\)

Therefore, the atomic number and mass of Barium are 56 and 139, respectively. The correct answer isOption C: 56 and 139.

Correct Answer: A. Silicon

Correct Answer: D) do not settle out on standing, suspensions do

Correct Answer: C. iron

Correct Answer: B) 12.5s

Explanation

When gases pass through a porous plug, the rate at which they flow through the plug depends on their molecular weights. This concept is described byGraham's law of effusion, which states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass.

Graham's law can be expressed mathematically as:

\( \frac{Rate_1}{Rate_2} = \sqrt{\frac{M_2}{M_1}} \)

Where:

• Rate_1 andRate_2 are the rates of effusion of gas 1 and gas 2, respectively.
• M_1 andM_2 are the molar masses of gas 1 and gas 2, respectively.

In this question, we are given that 100 cm

Explanation

(a) (i) Faraday's first law of electrolysis states that the amount of a substance discharged at/dissolved from an electrode is directly proportional to the quantity of electricity that passes through the electrolyte.

OR

- The mass of an element deposited at the electrode is directly proportional to the quantity of electricity passed.

(ii) Strong electrolytes dissociate/ionize completely in aqueous solutions while weak electrolytes dissociate/ionize only slightly/partially in aqueous solution.

(b)

-it burns in air/oxygen;

- it undergoes addition reaction;-it undergoes polymerization,

- it undergoes substitution/precipitation reaction.

(c)i) hydrocarbon with double/triple bond/multiple bonds between at least a pair of carbon atoms.

(ii) CH\(_3\)COOH + CH\(_3\)OH? CH\(_3\)COOCH\(_3\) + H\(_2\)

(ii) Methylethanoate (d) addition of concentrated H\(_2\)SO\(_4\) ; - removal of the ester as soon as it forms; - increase the concentration of one of the reactants.

(e) 65.0g of Zn\(^2+\) will produce 6.02 x 10\(^23\) molecules of H\(_2\), OR 65.0g Zn = I molecule of H\(_2\)

∴ 3.75g of Zn = \(frac{3.75}{ 65}\) X 6.02 x 10\(^23\)

= 3.4 X 10 molecules

(f) Sea level rising: -severe climate changes,depletion of coral reefs; -alters ecosystem balance/setting animal on the move; - severe drought; flooding or( areas); - polar ice melting

(g)(i) equation B, H\(_2\) +C\(_2\)H\(_4\) --> C\(_2\)H\(_6\)

(ii) In equation B, H changes from zero to-1; C changes from +2 to +3 as Concentration (i)

(h)(i) an electron in an atom exists/revolves a circular orbit; - energy of an electron is quantified / has a fixed value; - an electron emits energy in the form of radiation when it moves from a higher energy state to a lower energy State.

(ii) Bohr's model cannot explain the more complicated spectra lines observed in spectra Other than that of hydrogen. (i) temperature; pressure/volume; -concentration

(j) (i) produces a gas/effervescence/bubbles- given off;- HCI will produce a more vigorous reaction/CH\(_3\)COOH will produce a less vigorous reaction.