Author: Bbosa Science

Geometrical optic (light) revision questions and answers

07/17/2021 0

Geometrical optic revision questions and answers 1. (a) (i) derive the relationship, for convex lens, where u is the object distance, v is the image ... Read More

Waves A-level revision questions with answers

07/13/2021 0

(a) What is meant by interference pattern as applied to waves. (03marks) When two sound waves meet they superpose. The interference pattern produced depends on ... Read More

Magnetism (A-level revision questions with answers)

07/11/2021 0

1. (a)(i) Write down an expression for the force on a charge, q coulombs moving with velocity, u, at an angle, α, to a uniform ... Read More

Preparation of alkenes from tertiary alkyl halides

07/10/2021 0

Tertiary alkylhalides in presence of  hot solution of  excess alcohol and  potassium hydroxide undergo elimination reaction to form alkenes. The mechanism is described as  E1 ... Read More

Preparation of alkenes from primary alkyl halides

07/10/2021 0

Preparation of alkenes from primary alkyl halides Primary alkyl halide react with hot solution of excess alcohol and potassium hydroxide to form alkenes. the mechanism ... Read More

Preparation of alkenes from tertiary alcohols

07/10/2021 0

Preparation of alkenes from tertiary alcohols Tertiary alcohols react with hot concentrated sulphuric or phosphoric acid to  give alkenes. The mechanism is described as E1 ... Read More

Preparation of alkenes from primary alcohols

07/09/2021 0

Primary alcohol react with hot concentrated sulphuric or phosphoric acid to form alkenes. The mechanism is referred to as elimination bimolecular(E2) because water molecule is ... Read More

Polymerization of dienes

07/09/2021 0

Polymerization of dienes Alkenes with conjugated double bond undergo polymerization to form polyalkenes with double bonds Example Please Subscribe to promote this website. Subscription is ... Read More

Polymerization of alkene

07/09/2021 0

Polymerization of alkene This is the is the joining of very many small molecules called monomers to form big molecules called polymers In presence of ... Read More

Ozonolysis (reaction of ozone with alkenes)

07/09/2021 0

Ozonolysis (reaction of ozone with alkenes) Ozone reacts with alkene to form unstable ozonide that is reduced by zinc in presence of hydrochloric acid to ... Read More

Reaction of alkenes with hydrogen bromide in presence of a peroxide

07/09/2021 0

Reaction of alkenes with hydrogen bromide in presence of a peroxide In presence of a peroxide, alkenes react with HBr by free radial mechanisms; but ... Read More

Reaction of alkene with water

07/09/2021 0

Reaction of alkene with water. The reaction is catalyzed by  an acid sulphuric acid or phosphoric acid. Alcohols are produced Example 1 Ethene reacts with ... Read More

Reaction of alkenes with halogens in presence of water.

07/09/2021 0

Reaction of alkenes with halogens in presence of water. The reaction is carried out by bubbling alkenes through aqueous halogens. Example  Propene reacts with chlorine ... Read More

Reaction of alkenes with hydrogen halides (HX ; X = Cl, Br, I)

07/09/2021 0

Reaction of alkenes with hydrogen halides (HX ; X = Cl, Br, I) The reaction is carried out by bubbling HX through alkenes. Example 1 ... Read More

Reaction of alkenes with halogens

07/09/2021 0

Reaction of alkenes with halogens Halogens add across a double bond to form dihalogeno compounds. The reaction is carried out in an inert solvent like ... Read More

Reaction of alkenes with alkaline KMnO4 (potassium manganate) (VII) solution

07/09/2021 0

Reaction of alkenes with alkaline KMnO4 solution Dilute alkaline KMnO4 solution convert alkenes into compound called GLYCOLS (dihydroxyl alcohols) Please Subscribe to promote this website. ... Read More

Reduction of alkenes

07/09/2021 0

Reduction of alkenes They are reduced by hydrogen in presence of catalysts; nickel or platnum  to alkenes Example Please Subscribe to promote this website. Subscription ... Read More

Rules for naming alkanes or nomenclature of alkanes

07/09/2021 0

(a) Names of straight chain isomers alkanes Straight chain isomers are named according to the number of carbon atoms in the chain. (a) Naming branched ... Read More

What is alkyl groups?

07/09/2021 0

An alkyl group is an alkane less one hydrogen atom. Examples CH4                       Methane        CH3- methyl  group CH3CH3                Ethyl        ... Read More

Names of first ten straight chain alkanes

07/09/2021 0

Names of first ten straight chain alkanes Please Subscribe to promote this website. Subscription is free Share with a friend Your comment is valuable Thank ... Read More

Types of Isomerism in organic chemistry

07/09/2021 0

Types of isomerism Structural isomerism Optical isomerism Structural isomerism Here compounds differ in arrangement of atoms in a compound. (a) Chain isomerism: compound have the ... Read More

What is isomerism?

07/09/2021 0

what is isomerism? Isomerism is the existence of compound with the same molecular formulae but different arrangement of atoms in a compound. Please Subscribe to ... Read More

Dehydration of alcohol

07/09/2021 0

Dehydration of alcohol Alcohols are dehydrated by hot concentrated sulphuric or phosphoric acid to form alkenes. The mechanisms depend on the class of alcohols. Primary ... Read More

Oxidation of alcohols

07/09/2021 0

Oxidation of alcohols Alcohols are burnt in oxygen to produce carbon dioxide, water and heat. Due to production of heat on combustion, alcohols are used ... Read More

formation of alkylhalides from alcohols

07/09/2021 0

Formation of alkyl halides from alcohols Alcohols react with a variety of reagents to yield alkyl halides. The most commonly used reagents are hydrogen halides ... Read More

Reaction of alcohols with acid anhydride to form esters.

07/09/2021 0

Alcohols react with acid anhydride to form esters Example Please Subscribe to promote this website. Subscription is free Share with a friend Your comment is ... Read More

Reaction of alcohols with acid halides to form esters.

07/09/2021 0

Acid halides react with alcohols to form esters. Example Ethanoyl chloride reacts with methanol to form methylethanoate Please Subscribe to promote this website. Subscription is ... Read More

Reaction of alcohols with carboxylic acids to form esters

07/09/2021 0

Alcohols react with carboxylic acids in the presence of a mineral acid (phosphoric or sulphuric acid) to form esters. However, this is not a good ... Read More

Formation of ethers from alcohols

07/09/2021 0

Please Subscribe to promote this website. Subscription is free Share with a friend Your comment is valuable Thank you so much Read More

Laboratory preparation of alcohols

07/09/2021 0

  Please Subscribe to promote this website. Subscription is free Share with a friend Your comment is valuable Thank you so much Read More

Industrial preparation of alcohols

07/09/2021 0

  Please Subscribe to promote this website. Subscription is free Share with a friend Your comment is valuable Thank you so much Read More

Explain why a current carrying conductor placed in a magnetic field experience a force

06/26/2021 0

Explain why a current carrying conductor placed in a magnetic field experience a force The current in the wire setup a magnet field around the ... Read More

Explain the main precautions taken in the construction of an a.c. transformer

06/26/2021 0

Explain the main precautions taken in the construction of an a.c. transformer Low resistance copper wire are used to reduce I2R losses. Laminated core reduce ... Read More

Explain the application of eddy currents

06/26/2021 0

Explain the application of eddy currents. (03marks) Damping a 'galvanometer. In the galvanometer the coil is wound on a metal former. Eddy currents in the ... Read More

Explain how eddy currents can be produced. 

06/26/2021 0

Explain how eddy currents can be produced.  Eddy currents are currents induced in a conductor moving across magnetic field; these currents oppose the motion of ... Read More

Explain why an alternating current apparently flow through a capacitor whereas a direct current does not.

06/26/2021 1

Explain why  an alternating current apparently flow through a capacitor whereas a direct current does not. When a capacitor is connected to a d.c source, ... Read More

Derive an expression for the charge, Q, induced in a coil of N turns when the magnetic flux through it changes

06/26/2021 0

Derive an expression for the charge, Q, induced in a coil of N turns when the magnetic flux through it changes   Please Subscribe to ... Read More

Describe with the aid of a diagram, an absolute method of determining resistance

06/26/2021 0

Describe with the aid of a diagram, an absolute method of determining resistance The circuit is connected as above. The metal disc of known radius ... Read More

State one advantage of a.c over d.c

06/26/2021 0

State one advantage of a.c over d.c c can easily and cheaply be changed from one voltage to another. c can easily be transmitted with ... Read More

Explain why the primary current in the a.c. transformer increases when the secondary coil is connected to the load?

06/26/2021 0

Explain why the primary current in the a.c. transformer increases when the secondary coil is connected to the load?  When a load is connected to ... Read More

How can hysteresis loss be minimized in a.c. transformer?

06/26/2021 0

How can hysteresis loss be minimized in a.c. transformer? It is minimized by using soft magnetic materials like soft iron and perm alloy in which ... Read More

(iii) Explain why on average the power delivered to the inductor in one cycle is zero.

06/26/2021 0

Explain why on average the power delivered to the inductor in one cycle is zero. During the first quarter cycle, when current increases, work is ... Read More

Explain why the voltage at a generating power station must be stepped up to very high value for long distance transmission

06/26/2021 0

Explain why the voltage at a generating power station must be stepped up to very high value for long distance transmission At high voltage current ... Read More

Describe how the damping can be reduced in ballistic galvanometer

06/26/2021 0

Describe how the damping can be reduced in ballistic galvanometer Damping in ballistic galvanometer is reduced in the following ways Winding the coil on non-conducting ... Read More

State why the damping in the ballistic galvanometer should be as small as possible.

06/26/2021 0

State why the damping in the ballistic galvanometer should be as small as possible. When the oscillation in the ballistic galvanometer is damped, the deflection ... Read More

What is a Weber?

06/26/2021 0

What is a Weber? The weber is magnetic flux that passes normally though an area of 1m2. When the magnetic flux density is 1T. Please ... Read More

Explain why a moving coil ammeter is unsuitable for measuring alternating current

06/26/2021 0

Explain why a moving coil ammeter is unsuitable for measuring alternating current.  When an a.c is passed through a moving coil ammeter, the direction of ... Read More

Explain how an alternating current can be measured using a rectifier meter

06/26/2021 0

Explain how an alternating current can be measured using a rectifier meter When a.c is supplied to a rectifier meter, current flows in only one ... Read More

Describe an experiment which can be used to demonstrate self-induction

06/26/2021 0

Describe an experiment which can be used to demonstrate self-induction An iron cored coil is connected in series with a bulb, cell and switch as ... Read More

Explain why a current carrying conductor placed in a magnetic field experiences a force

06/26/2021 0

Explain why a current carrying conductor placed in a magnetic field experiences a force The current sets up magnetic field around the wire. When the ... Read More

Sketch on the same axes the variation with time of the voltage and current is a capacitor is connected to the voltage supply and explain your graph

06/26/2021 0

Sketch on the same axes the variation with time of the voltage and current is a capacitor is connected to the voltage supply and explain ... Read More

Show that when an inductor s connected to an a.c supply voltage of V = V0sin2πft, the resulting current lags the voltage by 900.

06/26/2021 0

Please Subscribe to promote this website. Subscription is free Share with a friend We value your comments Thank you so much Read More

Explain the variations of melting points of chlorides of period 3 elements

06/20/2021 1

Physical properties of chlorides of period 3 elements These are formed by reacting the elements with chlorine gas and the physical properties of their chlorides ... Read More

Explain the variations of boiling points of chlorides of period period 3 elements

06/20/2021 0

Boiling points of chlorides of period 3 elements The table below shows the boiling points of the chlorides of period 3 elements. Element Na Mg ... Read More

Animal production 2021 revision questions

06/18/2021 0

Animal production 2021   By Mungudit Davious Munguthdavious800@gmail.com +256 394847/7531322587 (a) A farmer wants to mix 16% proteins ration using maize which is 8% and ... Read More

A-level Animal production 2021 revision questions

06/18/2021 0

Agriculture revision questions for agriculture 3 Animal production 2021   By Mungudit Davious Munguthdavious800@gmail.com +256 394847/7531322587 (a) A farmer wants to mix 16% proteins ration ... Read More

Agriculture revision questions for agriculture 2 with answers

06/16/2021 0

Agriculture revision questions for agriculture 2 with answers Agricultural Economics 2021 By Mungudit Davious Munguthdavious800@gmail.com +256 394847/7531322587 (a) Describe the factors affecting labor efficiency (10marks)) ... Read More

Agriculture revision questions for agriculture 2

06/15/2021 1

Agriculture revision questions for agriculture 2 Agricultural Economics 2012 By Mungudit Davious Munguthdavious800@gmail.com +256 394847/7531322587 (a) Describe the factors affecting labor efficiency (10marks) (b) Outline ... Read More