Explanation

(a) Ways by which the Central bank regulates the activities of Commercial banks are:

(i)Open market operation:Central bank uses treasury bills which it sells to commercial banks when cash flow is desired to be restricted and purchase them when cash-flow is to be enhanced.

(ii)Liquidity ratio: Central bank requires commercial banks to maintain certain proportion or ratio of deposit at the central bank to control their propensity to lend.

(iii)Directives: Sometimes, the central bank issues specific instructions to the commercial banks for lending and saving policies, e.g., commercial banks convert their short term loans to long-term or medium-term-loans, especially in a depressing economy.

(iv) Special deposit: This is the percentage of deposit which the central bank requires commercial banks to make with at times when the economy is experiencing inflation.

(v) Moral persuasion: This is an appeal by the central bank to rnmercial banks to restructure its lending activities.

(vi) Regulating the Bank rate: When the bank rate rises, it riffles a reduction in loans granted by commercial banks while the fall encourages the bank to give more loans.

Factors to be considered by d bank manager before granting a loan to customers are:

(i) Customers' ability to pay. How long the customer has been banking with it.

(iii) The credibility of the customer in terms of credit worthiness

(iv) The position of the customer's account.

(v) The worth of the customer's collateral security, referee and guarantor.

(vi) The amount and period of repayment expressed by the customer.

(vii) The viability of the business.

Explanation

(a)(i) Define the term Hygroscopic: Hygroscopic substance – is defined as a substance which absorbs moisture on exposure to the atmosphere but does not form solution or change state.

(ii) Give two differences between a physical and a chemical change:

(iii) Using the kinetic theory of gases, explain briefly the Charles' law: At constant pressure, when the temperature of a gas is increased, the molecules gain more kinetic energy and move faster. The distance between the molecule increases resulting in increased in the volume of the gas.

(b)(i) Arrange the following compounds in order of increasing boiling points:

CO\(_2\), CS\(_2\), NaH

CO\(_2\) — Weak vander Waal's forces.

CS\(_2\) — Stronger vander Waals's forces.

NaH — With ionic forces stronger than vander Waal's forces.

(ii) Write a balanced equation to illustrate the reaction of chlorine gas with cold dilute sodium hydroxide.

Cl\(_{2(g)}\) + 2NaOH\(_{(aq)}\) \(\to\) NaCl\(_{(aq)}\) ; NaCI\(_{(g)}\) + H\(_2\)O\(_{(l)}\)

(c) In a certain reaction, 15.0g of impure magnesium sample reacted with excess hydrochloric acid liberating 8.6dm\(^3\) of hydrogen gas at s.t.p

(I) Write a balance equation for the reaction.

Mg\(_{(g)}\) 2HCI\(_{(aq)}\) ---> MgCl\(_{2(ag)}\) + H\(_{2(g)}\).

(ii) Calculate the: I. Mass of pure magnesium in the sample

Mg + 2HCI \(\to\) MgCl\(_2\) + H\(_2\)

1 mole H\(_2\) = 1 moles mg

n(H\(_2\)) = \(\frac{8.6}{ 22.4}\)

= 0.384moles.

Hence, number of moles of Mg = 0.384moles

Mass of Mg = mole x molar mass

= 0.384 x 24

= 9.21g.

II. % purity = \(\frac{\text{Mass of pure Mg}}{\text{Mass of impure Mg}}\) x 100

Mg = \(\frac{9.21}{15.0}\) x 100

= 61.4%

Ill. From the equation;

Moles of cl\(^{-2}\) = 2 x moles of Mg

= 2 x 0.384

= 0.768 moles

No of Cl\(^{-}\) produced x N\(_A\)

= 0.768 x 6.02 x 10\(^{23}\)

= 4.62 x 10\(^{23}\) Cl\(^{-}\)

Correct Answer: A. uninsurable risk

Correct Answer: D. a river port

Correct Answer: C. It was dark. The flood covered the bridge. The lorry crashed into the stream.

Correct Answer: D) Lowest in the tube with sandy soil

Explanation

Three 30cm lengths of glass tubing are tightly packed with different types of soil (clay, sand, and loamy soil) respectively and stood in a beaker of water for one week. The question is asking what will happen to the level of water in the tubes after one week. The options are: lowest in the tube with clay, the same in all the tubes, lowest in the tube with loamy soil, highest in the tube with sandy soil, and lowest in the tube with sandy soil (which is the correct option). When soil is packed tightly in a tube, it creates small spaces or pores between the soil particles. The size of these spaces varies depending on the type of soil. Sandy soil has larger spaces between particles, whereas clay has smaller spaces. Loamy soil is a mix of sand, silt, and clay and has medium-sized spaces. When the tubes are stood in a beaker of water, the water will move up the tubes through the spaces between the soil particles. However, because the size of the spaces varies between the different types of soil, the rate of water movement will also vary. Since sand has larger spaces between particles, water will move up the tube with sandy soil the fastest, resulting in the highest water level in that tube. On the other hand, clay has smaller spaces between particles, so water will move up the tube with clay the slowest, resulting in the lowest water level in that tube. Loamy soil has medium-sized spaces, so the water level in the tube with loamy soil will be in between the water levels of the tubes with clay and sand. Therefore, the correct option is D, lowest in the tube with sandy soil.

Correct Answer: D. ruse

Correct Answer: D. Partition Africa among European power

Correct Answer: D. reducing demand for a particular type of crop

Correct Answer: B. can be refracted and diffracted