logo



student ONLINE CANDIDATES : 85




PAYMENT FOR WAEC AND JAMB EXPO HAS STARTED, PAY NOW!!!



neco runs

WAEC / NECO / NABTEB /GCE SUBSCRIPTION PAYMENT EXPO


HOW TO PAY FOR WAEC/ NECO/ NABTEB /GCE ANSWER:

ALL SCIENCE ANSWERS + PRACTICAL COST: N5,500

ALL ART OR COMMERICAIL ANSWERS COST #4,500

 

WHATSAPP US AND SEND:- EXAM TYPE + MTN-CARD + PHONE NUMBER + SUBJECT TO 09055986588 (ONLY ON WHATSAPP)

UPDATE: Our Waec, Neco and Nabteb Exam Runs Payment is on, Earlyanswer is 100% Legit (Invite Your Classmates,Friends Here)

Answer Page

Answer Page

Confirmation page

Verify NECO / WAEC Payment

EARLYANSWER OFFICIAL WHATSAPP GROUP

JOIN OUR GENERAL WHATSAPP GROUP




« PREVIOUS POST:

| NEXT POST:

»

2020 NECO CHEMISTRY PRACTICAL QUESTIONS AND ANSWERS

(1)
Indicator used is methyl orange.
Volume of pipette used is 25cm³

Tabulate.
Titration; Rough|1st|2nd|3rd|

Final burette reading cm³|23.50|23.00|23.00|33.00|

Initial burette reading cm³| 00|0.00|0.00|10.00|

Volume of acid used(cm³) |23.50|23.00|23.00|23.00|

Average volume of A used = 23.00+23.00+23.00/3 =23.00cm³

Equation for the reaction
X²Co³(aq)+2HCl(aq)—->2XCl(aq)+H²O(s)+Cl(s)

(1i)
Concentration of A in moldm³ =concentration in gldm³.

3.6g of A =500cm²
Xg of A will be = 10000³
Xg=3.65*1000/500 =36.5/5 =7.3gldm³

Molar Mass of A HCl=1+35.5=36.5
Concentration of A =7.3gldm³/36.5gldm³
=0.20moldm³

(1ii)
Concentration of B in moldm³
concentration of A in moldm³ CA=0.20
Volume of used VA=23.00
Concentration of B in moldm³ CB=?
Volume of B used VB= 25.00

CAVA/CBVB = n(A)/n(B) =2/1
0.20*23.00/CB*25.00=2/1

2*CB*25.00=0.20*23.00*1
CB=0.20*23.00/50
Cb=46/50=0.092moldm-³

(1iii)
Molar mass of B in glmol
Concentration of B(moldm-³)= conc gldm³/molar mass
0.092=10.60gldm³/molar mass
0.092 * molar mass =10.60gldm³
Molar mass =10.60gldm³/0.092
=115.2glmd

(1iv)
Relative atomic mass of X in X²CO³
X²+12+3(16)=115.2
2x+12+48=115.2
2x+60=115.2
2x=115.2÷60
2x=55.2
x=55.2/2=276
====================================

(2i)
Tabulate.
TEST; C + 5cm³ of distilled water and shake thoroughly. Divide the solutions into three portions.

OBSERVATION; A pale green solution results

INFERENCE; salt is soluble

(2ii)
TEST; To the first portion add NaOH solution in drys

OBSERVATION; Dark green gelatinous was formed

INFERENCE; Fe²^+ present

(2iii)
TEST; then in excess

OBSERVATION; precipitate is insoluble

INFERENCE; Fe²^+ present

(2iii)
TEST; To the second portion add K3Fe(CN)6 solution

OBSERVATION; A dark blue precipitate formed

INFERENCE; Fe²^+ confirmed

(2iv)
TEST; To the third portion add AgNO³ solution

OBSERVATION; White Precipitate formed

INFERENCE; SO4²^- , CL^- CO²^- present

(2v)
TEST; To the results obtained in add dilute HNO3 in drops , then excess

OBSERVATION; White Precipitate is insoluble

INFERENCE; CL^- present

(2vi)
TEST; To the results obtained in add NH3 solution

OBSERVATION; White Precipitate dissolves

INFERENCE; CL^- Confirmed
================================

(3ai)
Filtration

(3aii)

 

(3bi)
I. Methyl Orange
II. Methyl orange
III. Phenolphthalein

(3bii)
A white Precipitate is observed. Effervescence occurs a gas is evolved which change lime water milky.
=========

Posted by on 28th September 2020.

Tags: ,

Categories: NECO

HOW TO WIN MTN CARD FROM EARLYANSWER
 
CLICK HERE TO SHARE THIS WEBSITE TO YOUR WHATSAPP FRIENDS / GROUPS AND WIN MTN CARD NOW

Chat Admin After You Share To 20 People On Whatsapp to Redeem The Price

Click here to submit your phone number for free updates about WAEC, NECO, NABTEB, GCE.

2023/2024 EXAM RUNS UPDATES👇

CLICK HERE TO GET WAEC 2023 EXAM RUNS


CLICK HERE TO GET NECO 2023 EXAM RUNS


CLICK HERE TO GET NABTEB 2023 EXAM RUNS


Our Answer Page for All Examination

4 Responses

  1. i love you guy

    by No cash on Oct 20, 2020

  2. please I need chemistry practical answers

    by Anonymous on Oct 21, 2020

  3. Nafiu

    by Thanks on Mar 13, 2022

  4. Anonymous

    by Pls is this the ans of this year neco chemistry practical on Jul 13, 2022

Leave a Reply

« PREVIOUS POST:

| NEXT POST:

»