WAEC Past Questions and Answers - Page 1283

6,411.

A business is treated as being separated from owners. This statement is emphasized by

A.

Consistency concept

B.

Realization concept

C.

Going concern concept

D.

Business entity concept

Correct answer is D

No explanation has been provided for this answer.

6,412.

The accumulative fund of a non-for-profit making organization is

A.

Consistency concept

B.

Realization concept

C.

Going concern concept

D.

Business entity concept

Correct answer is D

No explanation has been provided for this answer.

6,413.

How many moles of copper would be deposited by passing 1 Faraday of electricity through a \(CuCl_2\) solution?

A.

2 moles

B.

0.5moles

C.

0.025moles

D.

1 mole

Correct answer is B

1 Faraday of electricity is equal to the charge of 1 mole of electrons, which is 96,485 coulombs. The reduction of copper(II) ions in solution to copper metal requires 2 electrons per ion, so 1 Faraday of electricity will deposit 0.5 moles of copper.
1 Faraday * (2 electrons/Cu ion) / (1 mole electrons/96,485 coulombs) * (1 mole Cu/2 electrons) = 0.5 moles Cu

6,414.

How many grammes of NaOH(s) would be needed to produce 100.0 cm3 of a 0.20 mol dm-3 NaOH, (aq)? [NaOH = 40.0]

A.

800.0g

B.

0.02 g

C.

20.0 g

D.

0.80 g

Correct answer is D

Amount (in moles) = Molarity × Volume
Amount (in moles) = 0.20 mol/dm³ × 100.0 cm³ / 1000 cm³/dm³ = 0.020 moles
Now, we can calculate the mass using the formula:
Mass = Amount × Molar Mass
Mass = 0.020 moles × 40.0 g/mol = 0.80 g
So, the correct answer is:0.80 g

6,415.

Thermal cracking of alkanes usually

A.

is an exothermic process

B.

produces only small alkanes

C.

involves decomposition

D.

requires hydrogen

Correct answer is C

Thermal cracking is a process used in the petroleum industry to break down long-chain alkanes (hydrocarbons) into smaller, more useful hydrocarbons. It involves the decomposition of high-molecular-weight hydrocarbons, such as heavy crude oil fractions or long-chain alkanes, into lower-molecular-weight hydrocarbons, like smaller alkanes and alkenes. During thermal cracking, high temperatures and sometimes pressure are applied to the feedstock (such as crude oil or natural gas) to initiate the decomposition reactions.