JAMB Past Questions and Answers - Page 1185

5,921.

If the volume of a given mass of a gas at 0ºc is 29.5cm\(^3\). What will be the volume of the gas at 15ºc, given that the pressure remains constant. 

A.

31.6

B.

62.2

C.

32.7

D.

31.1

Correct answer is D

Charles' law is a special case of the ideal gas law in which the pressure of a gas is constant.

Charles's law defines the direct relationship between temperature and volume.

GIVEN DATA: V\(_1\) = 29.5cm\(^3\),  V\(_2\) = ? ,  T\(_1\) = 0ºc or 273k,  T\(_2\) = 15ºc or 288k

\(\frac{V_1}{T_1}\) = \(\frac{V_2}{T_2}\)

V\(_2\) = \(\frac{V_1 x T_2}{T_1}\) → \(\frac{29.5 x 288}{273}\)

V\(_2\) = 31.1cm\(^3\)

5,922.

In which of the following will hydrogen form ionic compound? 

A.

HCL

B.

NaH

C.

NH\(_3\)

D.

CH\(_4\)

Correct answer is B

NaH is a saline (salt-like) hydride, composed of Na+ and H− ions

5,923.

2H\(_2\) + O\(_2\) → 2H\(_2\)O

From the equation above, calculate the volume of unreacted oxygen gas if a mixture of 50cm\(^3\) of hydroden and 75cm\(^3\) of oxygen are involved

A.

85cm\(^3\)

B.

50cm\(^3\)

C.

125cm\(^3\)

D.

55cm\(^3\)

Correct answer is B

Since 2 mol H\(_2\) reacted with 1 mol of O\(_2\)

: 50cm\(^3\) of hydrogen reacted with 25cm\(^3\) of oxygen

Remainder oxygen = Supplied amount - Reacted amount → 75cm\(^3\) - 25cm\(^3\)

= 50cm\(^3\)

5,924.

The concept which states that revenue should be recognized at the point when the sale is deemed to have been made is

A.

Matching

B.

Consistency

C.

Realization

D.

Going concern

Correct answer is C

No explanation has been provided for this answer.

5,925.

An organic compound contains 69% carbon, 15.3% hydrogen and 30.7% oxygen. Calculate the the empirical formula [C=12, H = 1, O = 16]

A.

C\(_4\)H\(_12\)O

B.

C\(_3\)H\(_9\)O

C.

C\(_4\)H\(_9\)O

D.

C\(_3\)H\(_8\)O

Correct answer is D

C  \(\frac{69}{12}\)   H  \(\frac{15.3}{1}\)     O  \(\frac{30.7}{16}\)

C = 5.75,  H = 15.3,  O = 1.92

C \(\frac{5.75}{1,92}\)    H  \(\frac{15.3}{1.92}\)     O  \(\frac{1.92}{1.92}\)

C\(_3\)H\(_8\)O