2024 NECO: HOW TO GET NECO QUESTION AND ANSWER BEFORE EXAM START

JUPEB: 2024 JUPEB EXAMINATION TIMETABLE

EXPO: 2024 NECO ANSWER DAILY SUBSCRIPTION PRICE LIST

NECO: 2024 NECO OFFICIAL TIMETABLE

# NECO 2018 Chemistry Practical Answer – June/July Expo

NECO Chemistry Practical Solution Questions and Answer – June/July 2018 Expo Runz

START SUBSCRIBING FOR ENGLISH ANSWER NOW BEFORE SUBSCRIPTION CLOSE. ENGLISH IS FIRST COME FIRST SERVE.

DIRECT MOBILE = N1,000

ALL OUR ANSWER IS BEFORE EXAM. DON’T DOUBT IT

You remember maths day. No free Answer————————————————————–

(1a)
Tabulate:

Titrations |Rough|1st |2nd |3rd |
Initial burette reading |0.00 |0.00 |2.00 |5.00 |
volume of Acide used |18.00|15.60|15.40|15.50|

(1ai)
Average volume of Acid used
VA = (VA1 + VA2 + VA3)cm3/3
VA = (15.60+15.40+15.50)/3
VA = 46.50/3
VA = 15.50cm3

(1aii)
2HCl(aq)+Na2CO3(aq)–>2NaCl(aq)+H2O(l)+CO2(g)

(1bi)
CA VA/CB VB =NA/NB
0.1moldm^-3 x 15.50cm3/CB x 25cm3 x 2/1
CB x 25cm3 x 2 = 0.1moldm^-3 x 15.50cm3 x 1
CB x 50 = 1.55
CB = 1.55/50 = 0.031moldm^-3

(1bii)
25cm^3—->0.031mole
1000cm^3—->x
x=1000*0.031/25=31/25
x=1.24moldm^-3

(1biii)
concentration in mold^-3 =Con glm^3 /molar mass
0.031moldm^-3=x/106
x=0.031*106
x=3.286gldm^3

================================

2a)

Tabulate

2ai)
OBSERVATION:

i)C dissolves in water

ii)formation of white precipitate

iii)White precipitate dissolves in itel

INFERENCE:

i)C is soluble in water

ii)CO3^-2,SO4^-2,SO3^2- suspected

iii)CO3^2-,SO3^2-, suspected

2bi)
OBERSVATION:

i)effervescence occurs with the evolution of a gas

ii)the solutions turns to pink

INFERENCE:
i)CO3^2-,SO3^2-, suspected

ii)CO3^2-,Confrimed

================================

3ai)
Zinc chloride reaction with HaOH form white gelatinous precipitate solution in excess HaOH.
Ammonium trioxocarbonate(iv) on reaction with HaoH evolves a gas which turns red litmus paper blue and lime water milky. Calcium trioxocarbonate(iv) on reaction with HaoH forms white powdery precipitate insoluble in excess HaOH.

3aii)
i)liquid substance–> crystallization
ii)Solid substance–> precipitation

3bi)
i)Evaporation takes place at all temperatures, while boiling occurs at a particular temperatur (at boiling point).
ii)Evaporation takes place from the surface, whereas the entire liquid boils.

3bii)
Carbon(iv)oxide does not support combustion

3ci)
molar solution is an aqueous solution that contains 1 mole (gram-molecular weight) of solute in 1 liter of the solution.

3cii)
Indicator

3ciii)
i)methyl orange
ii)Phenolphthalein.

================================

=======Completed======

GOODLUCK

=========================

Expospy.com posts all exam expo answer earlier than others

============================

GOODLUCK!!!