Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
MCl
MCl2
MCl3
M2Cl6
Correct answer is C
Percentage by mass of M = 20.22%
Percentage by mass of Cl = ?
100 - 20.22 = 79.78%
Mass given ration of M
M = 20.22/27 = 0.75
Chlorine = 79.78/35.5 = 2.24
Divide by the smallest
M = 0.75/0.75 = 1
Cl = 2.24/0.75 = 3
∴ The formula = MCl3
0.3g
1.5g
2.4g
3.0g
Correct answer is B
Molar conc. =no.of moles／Vol in dm3
Vol=250cm3= 0.25dm3
Molar conc=0.5M
No of moles=molar conc *Vol in dm3
=0.5*0.25
=0.125mole of HCl
2moles of HCl → １Mole of Mg
0.125 mole →(0.125*1)/2
=0.0625mole of Mg
Reacting mass=no of moles* molar mass
Mg=24
Mass=0.0625*24
=1.5g
Which of the following will have its mass increased when heated in air?
Helium
Magnesium
Copper pyrites
Glass
Correct answer is B
No explanation has been provided for this answer.
91K
182K
273K
819K
Correct answer is A
From P1/T1 = P2/T2 = 9/273 = 3/T2
T2 x 9 = 273 x 3
T2 = (273 x 3)/9
T2 = 91K
Propane
Oxygen
Methane
Ammonia
Correct answer is C
No explanation has been provided for this answer.