Monday, May 30, 2016

NECO 2016/2017 May/June Chemistry Praticals Answers Posted Here [31/05/2016]

>>>...Continue Reading After The Below Advertisement...>>>
CURRENT EXAMINATION:

NECO Chemistry Praticals Questions & Answers [31/05/2016];
TO GET ANSWERS EARLIER CLICK ON THIS LINK AND LIKE OUR FACEBOOK PAGE

TO GET ANSWERS EARLIER CLICK ON THIS LINK AND FOLLOW US ON TWITTER PAGE 

1)
volume of pipette used =25.0cm^3
indicator used =methyl orange
burette reading|rough| 21.50|0.00|21.50|
final burette readings (cm^3)|1st|21.20| 0.00. 21.20|
initial burette reading(cm^3)|2nd|31.20|10.00| 21.20|
volume of a used (cm^3)|3rd|41.20|20.00|21.20|
average volume of a used =(21.20+21.20+21.20)cm^3/3
=63.60cm^3/3
=21.20cm^3
equation of the reaction
H2SO4(aq) + 2NaoH(aq)+2H2O(s)
nA=1,nB=2
A=4.90gldm^3 H2SO4
molar mass H2SO4
=(1*2)+32+(16*4)
=2+32+64
=98gmol^-1
molar conc A=mass con A/molar mass A
=4.90gldm^3/98glmol
=0.05moldm^3
CAVA/CBVB=nA/nB
0.05moldm^3*21.20cm^3/CB*25.0cm^3=1/2
0.05moldm^3*21.20*2=CB*25.0
CB=0.05molldm^3*21.20*2/25.0
CB=0.0848moldm^3
in mass conc B =Molar B*MolarBmass
B=NaoH
=23+16+1
=40gmol-^3
mass conc B =0.0848moldm^3 * 40gmol
mass con B = 3.392gldm^3
% mass of impusx 100%/total mass of implusty
mass of implus =(4.0-3.392)gldm^3
=0.608gldm^3
%impurity =0.608gldm^3*100%/4.0gldm^3
=15.2%
------------------------------------------------------------------------------------------------------------------
(2ai)
Observation: The salt sample dissolves completely
Inference: C is a mixture of soluble salts

(2aii)
Observation: White precipitate insoluble in excess NaOH(aq)
Inference: Ca^2+ present

(2aiii)
Observation: No visible reaction
Inference: Ca^2+ is present

(2aiv)
Observation: Brownish fume is produced
Inference: NO2(g) form, NO3^- present

(2av)
Observation: Formation of brown gas which forms a ring junction with FeSO4
Inference: NO2 form, NO3^- confirmed

(2bi)
Observation: D dissolves completely. Formation of dirty green precipitate insoluble in excess NaOH(aq)
Inference: D is soluble in salt, Fe^2+ present

(2bii)
Observation: Formation of a white precipitate.precipitate remains insoluble in HCl(aq)
Inference: SO3^2-,CO3^2-,SO4^2- present,SO4^2

--------------------------------------------------------------------------------------------------------------------- 
3a] 

3ai)
Drawing lebel
-lid
-sticky tape(to hold paper)
-choroatographic paper
-gas jar
-applied spot of solute mixture
-ion
3aii)
principle of dillution, C1 V1=C2 V2
2.0molldm^3*40
3bi)
ethanol---->ethanoic (acid)---->trioxonotrate(v) (acid)
3bii)
indicators are used to determine the end point of the reaction and to test the acidity or alkalinity of a solution
CALL OR TEXT MR CHINEKS ON 08107431933 TO SUBSCRIBE FOR NECO Verified And Confirmed NECO Chemistry Praticals Questions & Answers
NOTE: 
DIRECT MOBILE=N600
LINK(ONLINE ANS) = N400 
Forward Your Name,MTN PIN,Subject Name, Phone number to: 08107431933

SUBSCRIPTION ENDS 30 MINUTES BEFORE EXAM COMMENCES

NOTE:  
Online Answers comes 1hrs:30mins after the Commencement.

Protected by Copyscape
Recommended And Important Links To Check-Out

JAMB: 2017 Assistance Programme [Enter Here]


WASSCE: 2017 Help/Assistance Programme [Enter Here]


➤ 2017 JAMB, WAEC, NECO, NABTEB Students Group [Join Now]


➤ Chapter Summary Of Independence [JAMB Recommended Novel For UTME] In PDF


➤ 2017/18 JAMB Brochure [UTME/DE](PDF Format Only)


JAMB 2017 UTME/DE Registration Guidelines


2017/18 JAMB Brochure(PDF Format Only)


2017/18 JAMB Recommended Novels For Lit-In-Eng Students


JAMB 2017 Registration Centres/Cafe(s)Nationwide


Check JAMB Mock Exam Center Allocation Online Free


JAMB General Admission Entry Requirements [UTME/DE]


94 Likely Questions From Each Chapter Of JAMB Novel- In Dependence


No comments:

Post a Comment

We Appreciate And Welcome Comments... Please Try To Drop Your Comment Or Views For This Post....

Note : All Comments Are Moderated And No Spamming
Text/Whats-app: +2348107431933.
Available Monday-Friday -10am-6pm

Next Previous Home

Post Top Ad

Post Center Ad

Post bottom Ad

ADVERTISEMENT: TAP HERE TO CLOSE THIS AD

DMCA.com Protection Status