Correct Answer: C. alkyne

Explanation

When water is dropped on calcium carbide (CaC₂), a chemical reaction occurs to produce calcium hydroxide and a gaseous hydrocarbon.

The balanced chemical equation for the reaction is:

CaC₂ (s) + 2H₂O (l) → Ca(OH)₂ (aq) + C₂H₂ (g)

The gaseous product formed is C₂H₂, which is commonly known as acetylene.

Now, let's classify C₂H₂:

• Alkanes are saturated hydrocarbons with only single bonds (e.g., ethane, C₂H₆).

• Alkenes are unsaturated hydrocarbons with at least one carbon-carbon double bond (e.g., ethene, C₂H₄).

• Alkynes are unsaturated hydrocarbons with at least one carbon-carbon triple bond (e.g., ethyne, C₂H₂).

• Alkanols are alcohols, which contain a hydroxyl (-OH) functional group (e.g., ethanol, C₂H₅OH).

Since C₂H₂ (acetylene or ethyne) contains a carbon-carbon triple bond (H-C≡C-H), it is classified as an alkyne.

The final answer is C

Explanation

(I). The President is the Chief Executive of the country who performed the day to day administration of the country.

(ii). He inaugurated the National Assembly at the beginning of each session.

(iii). He assented to bills passed by the National Assembly into laws.

(iv). He appointed key officers e.g. ministers, ambassadors, the CBN Governor, Director of government agencies among others.

(v). He represented the country at international conferences like UNO, AU, Commonwealth, ECOWAS, etc.

(vi) He was the Commander-in-Chief of the Armed Forces.

(vii). He performed ceremonial functions

(viii). He exercised prerogative of mercy: He pardoned convicted persons or those found guilty of treasons.

(ix). He signed treaties with other countries on behalf of the country.

(x). He formulated policies for good governance.

(xi). He prepared and presented annual budget to the National Assembly for approval

(xii). He was empowered to declare a state of emergency/maintenance of law and order.

(xiii). He presides over executive council.

(xiv). He received ambassadors from other countries/ He maintained external relations with other countries.

(xv). He could declare war subject to the approval of the National Assembly.

(xvi). Declare National Assembly close i.e. prorogue

Correct Answer: B. tactic movement

Correct Answer: C. aggressor

Correct Answer: D. product differentiation

Correct Answer: D. \(\begin{pmatrix} 0 & 10 \\ 9 & -4 \end{pmatrix}\)

Explanation

\(P = \begin{pmatrix} 2 & 1 \\ 5 & -3 \end{pmatrix} ; Q = \begin{pmatrix} 4 & -8 \\ 1 & -2 \end{pmatrix}\)

\(2P = \begin{pmatrix} 4 & 2 \\ 10 & -6 \end{pmatrix}\)

\(2P - Q = \begin{pmatrix} 4 & 2 \\ 10 & -6 \end{pmatrix} - \begin{pmatrix} 4 & -8 \\ 1 & -2 \end{pmatrix}\)

= \(\begin{pmatrix} 0 & 10 \\ 9 & -4 \end{pmatrix}\)

Correct Answer: A. At least two witnesses

Correct Answer: A. 2

Explanation

\(\frac{3x + 4}{(x - 2)(x + 3)}≡\frac{P}{x + 3}+\frac{Q}{x - 2}\)

\(\frac{3x + 4}{(x - 2)(x + 3)}=\frac{P(x-2)+Q(x+3)}{(x-2)(x+3)}\)

=\(3x+4=P(x-2)+Q(x+3)\)

=\(3x+4=Px-2P+Qx+3Q\)

=\(3x+4=Px+Qx-2P+3Q\)

=\(3x+4=(P+Q)x-2P+3Q\)

Equating x and the constants

P+Q=3------(i)

2P+3Q=4-------(ii)

From equation (i)

P=3-Q------(iii)

Substitute (3-Q) for P inequation (ii)

=-2(3-Q)+3Q=4

=-6+2Q+3Q=4

=-6+5Q=4

=5Q=4+6

=5Q=10

∴Q=\(\frac{10}{5}=2\)

Correct Answer: D. perishable

Correct Answer: C. has to be very careful in his relationship with Wang

Explanation

can't be too careful is an idiomatic phrase. The phrase simply means that one shouldn't take (unnecessary) risks, that one needs to be watchful, prepared, or prudent: you can't be too careful: used for saying that it is important not to take risks.