Welcome guest, Login or Register to gain full access
Neco Gce 2017 Chemistry Obj And Theory Answers – Nov/Dec Expo
Views: 762
Posts: 1
chidusky
chidusky (m)
0 year ago

NOTE THAT MATHEMATICS QUESTION AND ANSWERS ARE NOW READY WITH US!
-DIRECT ANSWER = #1000
-PASSWORD = #600
FORWARD TO 09033919669


NECO GCE - CHEMISTRY ANSWERS
Exam Time: Thursday, 9th November, 2017
Chemistry (Theory And Obj)
2pm – 5pm
===================

1-10 aaebbdcaac
11-20 abbcbddbcd
21-30 babdebbbcbb
31-40 cbbebbbcbb
41-50 e-cbbedbde
51-60 acbbdccedb


(3ai)
petroleum gas and petrol->kerosene->diesel->asphalt

(3aii)
I-asphalt
II-kerosene
III-petroleum gas and petrol
IV-asphalt

(3bi)
(i)ethene
(ii)propene

(3bii)
(i)structural isomerism
(ii)steveo isomerism

(3biii)
19R-1s^2 2s^2 2P^6 3S^2 3P^6 4S^1
10S-1S^2 2S^2 2P^6
24T-1S^2 2S^2 2P^6 3S^2 3P^6 4S^2 3D^4

(3biv)
group 6

(3ci)
I- AgNO3(aq) and BaCl2
II-BaCl2 and Na2SO4
III-Ca(NO3)2 and H2CO3(aq)

(3cii)
(i)fitteration
(ii)flocculation
(iii)disinfection

(3d)
Mass of NaCl
= mass of Nacl + mass of H2O
= (23 + 35.5) + 80g
= 58.5 + 80g = 138.5g
Hence
Since 39.8g at 100°C = 35.9g at 15°C
138.5g at 100°C = Xg at 15°C
X = 138.5 × 35.9/39.8g
= 124.9g at 15°C
Hence mass of Nacl precipitated
= 138.5 - 124.9g
= 13.6g of Nacl
==============================

(5a)
(i) increasing the surface area
By adding catalyst to the reaction
(ii)0.896dm^3 of CO2 was produced by 4g of caco3
(iii)
If 100g of caco3-----1mole of co2(22.4dm3)
4g------X
X=4*22.4/100
X=0.896dm3

(5bi)
(i)atom the smallest particle of a chemical element that can exist.
(ii)molecule is a group of atoms bonded
together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
=======================

(2a)
(i)Temporary hardness is caused by dissolved calcium hydrogencarbonate
(ii)Permanent hardness is caused by dissolved calcium sulfate.

(2bi)
(i)Temporary Hardness can be Removed By Boiling
(ii)Permanent hardness can be removed by ... washing soda (sodium carbonate); ion exchange; the use of polyphosphate water softeners.

(2bii)
Advantages
(i)Calcium ions in the water are good for children's teeth and bones.
(ii)Some brewers prefer using hard water for making beer.

(2biii)
Disadvantages
(i)It is more difficult to form a lather with soap.
(ii)Scum may form in a reaction with soap, wasting the soap.

(2ci)
A saturated solution is a chemical solution containing the maximum concentration of a solute dissolved in the solvent.

(2ciii)
- Anthracite Coal
- Bituminous coal
- Sub-bituminous coal

(2civ)
The anthracite coal: They are the purest forms of coal

(2d)
- Zinc is not a transition metal because it forms only Zn2+ ions with all the 3d electrons present.
- Zn not a transition metal, because it forms only Sc3+ ions with n d-electrons

(2dii)
Fine Chemicals: This is a chemical compound made in relatively small amounts and in a comparatively pure state.


================
KEEP REFRESHING THIS PAGE
================
Add a Comment:
Sponsored ads
  • Quick search
Who's viewing this