Chemistry 2016 Jamb Examination
Chemistry 2016 Jamb Examination
Question 11
The colour of litmus in an alkaline medium is
The correct option is D. Blue.
Litmus is a pH indicator that changes color based on acidity or alkalinity. In an alkaline (basic) medium, litmus turns blue, while in an acidic medium it turns red.
Litmus is a pH indicator that changes color based on acidity or alkalinity. In an alkaline (basic) medium, litmus turns blue, while in an acidic medium it turns red.
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Question 12
The compounds CH\(_3\)CH\(_2\)CHO and CH\(_3\)COCH\(_3\) can be distinguished from each other using
The correct option is C. Tollen's reagent.
CH\(_3\)CH\(_2\)CHO is an aldehyde (propanal), while CH\(_3\)COCH\(_3\) is a ketone (propanone). Tollen's reagent oxidizes aldehydes to carboxylic acids and produces a silver mirror, but it does not react with ketones. Thus, it distinguishes the two compounds.
CH\(_3\)CH\(_2\)CHO is an aldehyde (propanal), while CH\(_3\)COCH\(_3\) is a ketone (propanone). Tollen's reagent oxidizes aldehydes to carboxylic acids and produces a silver mirror, but it does not react with ketones. Thus, it distinguishes the two compounds.
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Question 13
Which of the following statements is true about 2-methylpropane and butane
The correct option is B. They are members of same homologous series.
Both 2-methylpropane (isobutane) and butane are alkanes with molecular formula C\(_4\)H\(_{10}\). They are structural isomers and therefore belong to the same homologous series but have slightly different physical properties.
Both 2-methylpropane (isobutane) and butane are alkanes with molecular formula C\(_4\)H\(_{10}\). They are structural isomers and therefore belong to the same homologous series but have slightly different physical properties.
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Question 14
The process that requires the use of hard water in its operation is
The correct option is B. Bottling.
In the bottling of mineral water, hardness (especially temporary hardness) is desirable because it provides essential minerals like calcium and magnesium, improving taste and quality. In other processes like laundry or dyeing, soft water is preferred.
In the bottling of mineral water, hardness (especially temporary hardness) is desirable because it provides essential minerals like calcium and magnesium, improving taste and quality. In other processes like laundry or dyeing, soft water is preferred.
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Question 15
What is the concentration of a solution containing 2g of NaOH in 100cm\(^3\) of solution?
[Na = 23, O = 16, H = 1]
[Na = 23, O = 16, H = 1]
The correct option is C. 0.50 mol dm\(^{-3}\).
Given:
Mass of NaOH = 2 g
Molar mass of NaOH = 23 + 16 + 1 = 40 g mol\(^{-1}\)\[ \text{Number of moles} = \dfrac{2}{40} = 0.05 \; \text{mol} \]Volume = 100 cm\(^3\) = 0.1 dm\(^3\)
Concentration\[ = \dfrac{0.05}{0.1} = 0.5 \; \text{mol dm}^{-3} \] Hence, the concentration of the solution is 0.50 mol dm\(^{-3}\).
Given:
Mass of NaOH = 2 g
Molar mass of NaOH = 23 + 16 + 1 = 40 g mol\(^{-1}\)\[ \text{Number of moles} = \dfrac{2}{40} = 0.05 \; \text{mol} \]Volume = 100 cm\(^3\) = 0.1 dm\(^3\)
Concentration\[ = \dfrac{0.05}{0.1} = 0.5 \; \text{mol dm}^{-3} \] Hence, the concentration of the solution is 0.50 mol dm\(^{-3}\).
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Question 16
The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is
The correct option is B. Cobalt-60.
Cobalt-60 emits strong gamma radiation, which can penetrate metals. It is used in industrial radiography to detect internal defects in welds and castings without damaging the material.
Cobalt-60 emits strong gamma radiation, which can penetrate metals. It is used in industrial radiography to detect internal defects in welds and castings without damaging the material.
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Question 17
The compound produced when sodium peroxide is heated with excess sodium is
The correct option is B. Na\(_2\)O.
When sodium peroxide (Na\(_2\)O\(_2\)) is heated with excess sodium, it is reduced to sodium oxide:
\[ \text{Na}_2\text{O}_2 + 2\text{Na} \rightarrow 2\text{Na}_2\text{O} \]
Thus, the product is sodium oxide (Na\(_2\)O).
When sodium peroxide (Na\(_2\)O\(_2\)) is heated with excess sodium, it is reduced to sodium oxide:
\[ \text{Na}_2\text{O}_2 + 2\text{Na} \rightarrow 2\text{Na}_2\text{O} \]
Thus, the product is sodium oxide (Na\(_2\)O).
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Question 18
The pollutant that contributes to the depletion of the ozone layer is
The correct option is A. CFCs.
Chlorofluorocarbons (CFCs) release chlorine atoms in the stratosphere, which react with ozone molecules, breaking them down and causing ozone layer depletion.
Chlorofluorocarbons (CFCs) release chlorine atoms in the stratosphere, which react with ozone molecules, breaking them down and causing ozone layer depletion.
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Question 19
Which of the following properties is not peculiar to matter?
The correct option is B. Random motion of particles increases from gas to solid.
This statement is false because random motion decreases from gas → liquid → solid. In solids, particles are tightly packed and vibrate in fixed positions, showing minimal random motion.
This statement is false because random motion decreases from gas → liquid → solid. In solids, particles are tightly packed and vibrate in fixed positions, showing minimal random motion.
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Question 20
Cast iron is used in making
The correct option is D. Stoves and cookers.
Cast iron is hard and brittle with high carbon content, making it suitable for manufacturing heavy and heat-resistant items such as stoves, cookers, and engine blocks.
Cast iron is hard and brittle with high carbon content, making it suitable for manufacturing heavy and heat-resistant items such as stoves, cookers, and engine blocks.
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"Forty more days and Nineveh will be overturned." When Jonah passed this message to the people of Nineveh, what did they do?
For this question, select the option that best explains the information conveyed in the question.
These job cuts are just the thin end of the wedge
I. change of state
II. Diffusion
III. Radiation
IV. Osmosis
Which of the processes above can be explained using the kinetic theory?