2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
=============================
CHEMISTRY OBJ:
1-10: ABDCBCABAC
11-20: DACBBACCAA
21-30: CBCDCAAACB
31-40: AACACBABAA
41-50: DBBDDBDCDB
=============================
(1ai)
Fermentation is the process in which a substance breaks down into a simpler substance. Microorganisms like yeast and bacteria usually play a role in the fermentation process, creating beer, wine, bread, yogurt and other foods.
(1aii)
Zymase
(1b)
-The strength of an acid
-The PH of the solution
(1c)
Fe+H2SO4->FESO4 + H2
H2SO4=10cm^3
Concentration=1mol/dm^3
Amount=Vol * Concentration
=10/100*1
=0.01mol
1mol=56g
0.01mol=56*0.01
=0.56g
Mass of unreacted=5-0.056
=4.44g
(1d)
(i) NaOH(aq)
(ii) Poly-propenitrite
(1e)
A catalyst increases the rate of a chemical by swinging it’s activation every.
(1f)
(i) CH3CooH + NH3 —->CH3CooH2 + H2O
(ii) Ethanoamide
(1g)
(a) It doesn’t corrode easily.
(b) it doesn’t react with contain inside.
(c) It can stand for a long period of time.
(1h)
(a) Sweet production industries
(b) perfume industries.
(1i)
(a) E
(b)
(1j)
(a) it increases the volume water in ocean and seas.
(b) It causes increase in rainfall and also corrode painted surfaces
============================
2ai)
Collision theory states that the rate of a reaction depends on the rate of collision of the reactant molecules. Hence effective collision determines the rate of the reaction because it is the collision that leads to the formation of a product.
(2aii)
When the rate of collision increases, the rate at which molecules collide with each other will also increase thereby making the kinetic energy of the molecules to also increase. The temperature will also increase because temperature is a measure of average kinetic energy.
(2bi)
Draw your diagram
(2bii)
C2H5OH + 3O2 —->2CO2 + 3H2O
1mole of ethanol = 3moles of O2
2.5moles of ethanol will require 3 × 2.5/1 = 7.5moles of O2.
but 1 mole of gas = 22.4dm3
7.5moles = 7.5 × 22.4 = 168dm3 of O2.
(2Ci)
Esterification is the formation of an Ester by the reaction between Alkanol and an acid.
(2cii) Two uses of alkanols
(i) They are used as solvents for cellulose
(ii) They are uses in making perfumes and cosmetics.
(iii) They are used for quick drying of paints and nail varnishes.
(2ciii)
Sodium Ethanoate
(2di)
Tin
(2dii )
This is because the galvanized plate is corrosion-resistant. It has a protective coating which prevents further oxidation of the metal.
=============================
(3ai)
H H H H H
| | | | |
H-C-C-C-C-C-C=C-H Heptene
| | | | | |
H H H H H H
(3aii)
The sixth member of Allene C7H14 =
7(molecular mass of carbon) + 14(molecular mass of H)
= 7(12) + 14(1)
= 84 + 14 = 98gmol-¹
(3aiii)
-Cracking is the breaking down of higher molecules into smaller molecules while reforming is the change in the functional group or activity of the compound.
-In cracking more than one product or component is formed. But in reforming one product can still be gotten.
(3bi)
Enthalpy of Neutralization change is the heat change which offers when one mole of H+ from an acid reacts with one mole of OH- from an alkali to form one mole of water.
(3bii)
Weigh about 100cm³ of dil HCL(aq) and that of KOH(aq) of equal volume and put each into a glass calorimeter. The temperature of the two Solutions are taken. The mean volume of the temperature of the acid and base taken. Then quickly transfer the alkali to the acid, turn and take the final temperature of the solution. Record the mass of the mixture. Find the temperature difference.
Total heat covered = mass × specific heat capacity × temperature change.
(3ci)
I – copper
II – silver
(3cii)
Because silver is below copper in the electrochemical series.
(3ciii)
Oxidation – anode
Reduction – Cathode
(3civ)
Cu(s)+2Ag+ –>Cu²+ + 2Ag
(3d)
(i) Brown hydrated Iron(iii)oxide (FeO3 . xH2O)
(ii) 4Fe(s) + 3O2(g)+2xH2O ->2Fe2O3. xH2O(s)
(iii) Haematite
============================================
(4ai)
(4aii)
Na2SO3(aq) +2HCl(aq) ->2NaCl(aq)+H2O(l)+SO2(g)
(4aiii)
Dry the gas evolved by passing it through H2SO4 and collect it by downward delivery
(4aiv)
Because it is denser than air
(4bi)
It states that there is a mixture of gases which do not react chemically together,then the total pressure exerted by the mixture is the sum of the partial pressure of the individual gases that make up the mixture
(4bii)
T1=12C=285K
P1=690mmHg
V1=30cm^3
T2=273K
P2=760mmHg
V2=?
Using general gas law
V1P1/T1=V2P2/T2
V2=V1P1T2/T1P2
=(30*690*273)/(285*760)
V2=26cm^3
(4ci)
Cl2(g)+H20(l)->HCl(aq)+HOcl(aq)
2HOCl(sunlight)->2HCl(aq+O2(g)
(4cii)
Litmus turns red because of the presence of acid HCl
(4di)
Chlorine->Bromine->iodine (increasing boiling point)
(4dii)
Because water has two lone pairs of electrons as compared to ammonia which has one
COMPLETE CHEMISTRY QUESTIONS & ANSWERS NOW AVAILABLE. subscribe for the expo if you don’t want late answers
.
READ BELOW MESSAGES TO LEARN HOW TO SUBSCRIBE .
==================================================
CLICK HERE TO VIEW THE ANSWERS
==================================================
ANSWERS WILL BE SENT TO OUR SUBSCRIBERS BEFORE THE EXAM
EXPOLORD.CO TEAM ,ASSURE YOU NOTHING LESS THAN B2 IN THIS SUBJECT..ALL YOU NEED TO DO IS TO SUBSCRIBE.
Read below carefully to know how to subscribe for it.
-=-=-=-=-=-=-=HOW TO SUBSCRIBE=-=-=-=-=-=-=
DIRECT TO MOBILE AS SMS:
On this Direct mobile package we will send the Obj & Essay directly to your submitted phone numbers as early as we can…
>>>>>
Send 800 MTN CARD to 07068492504 + Subject name + phone number + i paid for direct sms
PASSWORD PAYMENT:
On this package of subscription, We will send a Password directly to your phone number, which will be Used to access the Answers Online. on our ANSWER PORTAL.
>>>>>
Send N400 MTN CARD to 07068492504 + Subject name + phone number with message i paid for online password
Our Online/Link Subscribers Will Get There answers on WWW.EXPOLORD.CO/ANSWERS-PAGE
WAEC 2018 RUNS SUBSCRIPTION
Our Subscription Price List For Direct Mobile.
(i) Per Subject: N800 each
(ii) Maths & English: N1000 each
Our Subscription Price List for WhatsApp Message.
(i) Per Subject: N600 each
(ii) Maths & English: N1000 each
Our Subscription Price List For Password Answers.
(i) Per Subject: N400 each
(ii) practicals Per Subject: N300 each
(iii) Maths & English: N800 each
HOW TO MAKE PAYMENT
Send
(i) Payment name/Your name.
(ii) Subject Name (e.g CHEMISTRY)
(iii) MTN Recharge Card Pin(s)
(iv) Phone number to 07068492504
Remember Success is not a must, is an Option.
Don’t let this little amount of money make you fail this exam.
WARNING:-Please Don’t Even Come for Free Answers, because it Would’nt be Posted. Take me Serious This Time.
Make Sure you Subscribe if you Don’t Want to be on Hot Seat
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
2018 WAEC RUNZ CHEMISTRY ESSAY & OBJ QUESTIONS AND ANSWERS
The truth just shines thogurh your post