# INTRODUCTION

#### PART TWO SERIES

Welcome to second edition of the poschools jamb tutorials In this Jamb tutorial series , I will be revealing jamb repeated questions and likely jamb questions and answers to expect  in Chemistry.

If this is your first time seeing this “jamb repeated questions and likely jamb questions and answers”. I will recommend you to check my part one series first here

It should be noted that this jamb repeated questions and likely jamb questions and answers to expect in chemistry was prepared based on hot topics set in Jamb Chemistry.

This “Jamb repeated questions and likely jamb questions and answers that will be set in chemistry series” will be released in a batch of 50 hot key points to help you pass jamb chemistry.

This 50 hot key points on  jamb repeated questions series will be strictly for organic chemistry.

In other words, we will be listing out jamb repeated questions on organic chemistry and also likely jamb questions and answers to expect from organic chemistry in 2019 jamb chemistry exam.

Jamb Repeated questions and likely jamb questions and answers to pass chemistry 2019 UTME exam will also be available for  physics so its wise you keep in touch with poschools

Check out key points to blast Jamb chemistry by clicking here

#### Jamb repeated questions in chemistry (1 to 10)

1. Unsaturated organic compounds can be identified by the decolourization of Bromine water and potassium per manganate.
2. Tetrachloromethane is a chlorinated .
3. The alkane homologous series is given by $C_{n}H_{2n+2}$. Also NOTE that each consecutive member of this homologous series differs by a $CH_{2}$ group
4. The three-dimensional shape of methane molecule is tetrahedral
5. A compound with a Sweet smelling smell like that of fruits is an ester also known as alkanoate.
6. The organic compound $C_{3}H_{6}Br_{2}$ has 4 isomers and the isomers are:
• 1,1-dibromo-propane
• 1,2-dibromopropane
• 2,2-dibromopropane
• 1,3-dibromopropane
7. The organic compound $C_{4}H_{10}$ has 2 isomers and the isomers are:
• n-butane
• 2-methylpropane also known as isobutane
8. The organic compound $C_{5}H_{12}$(pentane) has 3 isomers and the isomers are:
• n-pentane
• 2-methylbutane
• 2,2-dimethypropane
9. The organic compound $C_{6}H_{14}$ has 5 isomers and the isomers are:
• n-hexane
• 2-methylpentane
• 3-methylpentane
• 2,2-dimethylbutane
• 2,3-dimethylbutane
10. The Cracking process is important in the petroleum industries because it helps to yield more engine fuels

#### Jamb repeated questions in chemistry (11 to 20)

1. The process of obtaining compound with lower boiling points from compounds with higher boiling and melting point is termed cracking
2. Alkaline hydrolysis of naturally occuring fat and oils yield soap and glycerol
3. The Carboxylic acid also known as the alkanoic acid is represented by RCOOH
4. The Esters also known as alkanoates can be representd by RCOOR’
5. In esterification of ethanol and ethanoic acid, the Conc.$H_{2}SO_{4}$ used in the reaction acts as a Dehydrating agent
6. Complete hydrogenation of ethyne will yield ethane
7. Complete oxidation of alcohol will yield carboxylic acid also knnown as alkanoic acid.
8. When alcohol vapor is passed through a solution of potassium dichromate a colour change from orange to green occurs
9. Ammoniacal silver nitrate solution can be used to distinguish Alkenes from Alkynes
10. Thr process of converting oils to magarine or solid fat is termed HYDROGENATION

#### Likely Jamb questions and answers in chemistry (21-30)

1. The salt (sodium chloride) present in the saponification process helps to separate out the soap from the glycerol
2. The organic compound $C_{3}H_{8}O$ has 3 isomers which are:
• 1-propanol
• 2-propanol
• methoxyethane
3. When ethanol is heated in excess conc tetraoxosulphate vi acid, the ethanol is dehydrated to ethene gas
4. Alkanoic acid react with trioxocarbonate salts with the evolution of carbon(iv)oxide gas(i.e effervescence occurs during reaction of alkanoic acid with a trioxocarbonate salt $Na_{2}CO_{3}$
5. Lead tetra-ethyl is used as anti-knock in petrol engines
6. The reaction that occurs when Palm-oil is added to potash is with the formation of foam is termed Saponification
7. Starch is converted to Ethyl alcohol by the process called Fermentation
8. The efficiency of petrol as fuel in high compression internal combustion will increase in the presence of increased branch chain alkanes
9. The fuction of the ash in the locally made black soup is to supply the alkali necessary for saponification to take place.
10. Water added to calcium carbide in a container produces a gas called acetylene

#### Likely Jamb Chemistry questions and answers31-40)

1. Detergent have the following general formula $RSO_{3}Na^{+}$
2. When excess Chlorine is mixed with ethene an organic compound with the name 1,2-dichloroethane is produced
3. The bond which joins two ethanoic acid molecule in its liquid state is the Hydrogen bond. Note that this hydrogen bond also joins two molecules of ethanol together.
4. The gas responsible for the fatal explosion in the coal mines is the methane gas
5. cycloalkane with the formula $C_{5}H_{10}$ has
6. Alkanals can be differentiated from alkanones by their reaction with Tollen’s reagent
7. glucose and cellulose are examples of polysachharide.
8. The carbon atoms in the alkane homologue are sp3 hybridized
9. The carbon atoms in the alkene homologue are Sp2 hybridized
10. The carbon atoms in the alkyne homologue are Sp hybridized

#### Jamb repeated questions and likely questions and answers in chemistry)

1. The presence of copper sulphate solution in tetraoxosulphate(vi) acid in the preparation of acetylene gas it to remove the phosphine impurity produce.
2. Bromine water will confirm the presence of unsaturation in an organic compound
3. When sodium is added to ethanol the compound produced is Sodium ethoxide while hydrogen gas is also liberated
4. The general formula for alkanals or aldehydes is RCHO
5. The general formula for alkanones or ketones is RCOR’ or $R_{2}CO$.
6. The general formula for ether or alkyoxide is R-O-R
7. The relative high boiling points of alcohols is due to the presence of hydrogen bond
8. The products obtained when hydrocarbon is burned in the presence of excess air is water vapour and carbon(iv)oxide
9. Sulphur is used for the vulcanization of rubber
10. Ethanol is used as a solvent in perfume

Alright guys. Stay tuned for part two hot key points to blast Jamb commerce

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Philip Obhenimen

Hello world, first I want to thank you for visiting my blog and hope you find the content useful. My name is JOHN PHILIP OBHENIMEN the CEO of poschools.com I am currently studying mechanical engineering in a reputable university. I am very passionate about educating young people on academics,career and skill acquisition. I pray that the Almighty God help assists me in accomplishing the above.