Study and practice Chemistry past questions with answers and detailed explanations. Then test your knowledge using our interactive CBT practice platform and prepare confidently for your upcoming examinations.
When dilute aqueous solutions of lead (II) nitrate and potassium bromide are mixed, a precipitate is observed.
The products of this reaction are?
APbO(s) + Br- + KNO3
BBr2 + NO2(g) + PbBr2(s)
CPbO(s) + K+(aq) + Br(aq) + NO2(g)
DPbBr2(s) + K(aq) + K+(aq) + NO3(aq)
View Explanation & Discuss
Question 13
jamb1993
Which of the following is a property of ionic chlorides?
AThey can be decomposed by heat
BThey react with aqueous AgNO3 to give a white precipiate which is soluble in excess ammonia
CThey explode when in contact with dry ammonia
DThey react with concentrated tetraoxosulphate (IV) acid to give white fumes of chlorine gas
View Explanation & Discuss
Question 14
jamb1993
An experiment produces a gaseous mixtures of carbon (IV) oxide and carbon (II) oxide. In order to obtain pure carbon (II) oxide, the gas mixture should be?
Apassed over heated copper (II) oxide
Bbubbled through concentrated tetraoxosulphate (IV) acid
Cbubbled through sodium hydroxide solution
Dbubbled through water
View Explanation & Discuss
Question 15
jamb1993
Which of these salts will produce its metal, oxygen and nitrogen (IV) oxide on heating?
ASilver and trioxonitrate (V)
BSodium trioxonitrate (V)
CCalcium trioxonitrate (V)
DLithium trioxonitrate (V)
View Explanation & Discuss
Question 16
jamb1993
Which of these gases can be dried with concentrated H2SO4?
AHBr
BH2S
CNH3
DSO2
View Explanation & Discuss
Question 17
jamb1993
NaCI(s) + H2SO4(I) → HCI(g) + NaHSO4(s).
In the reaction above, H2SO4 behaves as?
Aa strong acid
Ban oxidizing agent
Ca good solvent
Da dehydrating agent
View Explanation & Discuss
Question 18
jamb1993
10g of a solid is in equilibrium with its own vapour.
When 1 g of a small amount of solid is added, the vapour pressure?
Aremains the same
Bdrops
Cincreases by 1%
Dincreases by 99%
View Explanation & Discuss
Question 19
jamb1993
The standard enthalpies of formation of CO2(g), H2O(g) and CO(g) in kJ mol- are -394, -242 and -110 respectively. What is the standard enthalpy change for the reaction CO(g) + H2(g)O → CO2(g) + H2(g)?
A-42 KJ mol-
B+42 KJ mol-
C-262 KJ mol-
D+262 KJ mol-
View Explanation & Discuss
Question 20
jamb1993
A reaction takes places spontaneously if?
A∆G = O
B∆S < O and ∆H > O
C∆H < T ∆S
D∆G > O
View Explanation & Discuss
Question 21
jamb1993
The oxidation states of chlorine in HOCL, HCLO3 and HCLO4 are respectively?
A-1, +5, and +7
B-1, -5 and 7
C+1, +3 and +4
D+1, +5 and +7
View Explanation & Discuss
Question 22
jamb1993
Which of the reactions occurs at the anode during the electrolysis of a very dilute aqueous solution of sodium chloride?
AOH- - e → OH
BCIsup>- - e → CI
COHsup>- + CIsup>-HCI + O2
DNa+ - esup>- Hg (Na)/(Hg) amalgam
View Explanation & Discuss
Question 23
jamb1993
During the electrolysis of a salt of a metal M, a current of 0.5 A flows from for 32 minutes 10 seconds and deposits 0.325 g of M, What is the charge of the metal ion?
(M = 65, If = 96,500 C per mole of electron)
A1
B2
C3
D4
View Explanation & Discuss
Question 24
jamb1993
4.0 g of sodium hydroxide in 250 cm3 of solution contains?
A0.40 moles per dm3
B0.10 moles per dm3
C0.04 moles per dm3
D0.02 moles per dm3
View Explanation & Discuss
Question 25
jamb1993
NH\(_3\) + H\(_3\)O\(^+\) → NH\(_4\)\(^+\) + H\(_2\)O. It may be deduced from the reaction above that?
Aa redox reaction has occurred
BH3O+ acts as an oxidizing agent
CH3O+ acts as an acid
Dwater acts as an acid
View Explanation & Discuss
Question 26
jamb1993
A student prepares 0.5 M solution each of hydrochloric and ethanoic acids and then measured pH. The result would show that the?
ApH values are equal
BHCI solution has a higher pH
Csum of the values is 14
Dethanoic acid solution has a higher pH
View Explanation & Discuss
Question 27
jamb1993
The phenomenon whereby sodium trioxocarbonate (IV) decahydrate loses some of its water of crystallization on exposure to the atmosphere is known as?
Adeliquescene
Bhygroscopy
Ceffervescence
Defflorescence
View Explanation & Discuss
Question 28
jamb1993
Water can be identified by the use of?
Aanhydrous copper (II) tetraoxosulphate (VI)
Banhydrous sodium trioxocarbonate (IV)
Cpotassium heptaoxochromate (VII)
Dcopper (II) trioxocaronate (IV)
View Explanation & Discuss
Question 29
jamb1993
The air around a petroleum refinery is most likely to contain?
ACO2, SO3 and N2O
BCO2, CO and N2O
CSO2, CO and NO2
DPH3 H2O and CO2
View Explanation & Discuss
Question 30
jamb1993
Argon is used in gas-filled electric lamp because it helps to?
