JAMB Chemistry Past Questions & Answers - Page 398

1,986.

The postulate of Dalton's atomic theory which still holds is that

A.

atoms can neither be created nor destroyed

B.

the particles of the same element are exactly alike

C.

particles of different elements combine in simple whole number ratio

D.

all elemets are made of small indivisible particles

Correct answer is A

Postulates of Dalton’s atomic theory can used to explain the behavior of matter:

All matter is composed of small tiny particles called atoms. In Greek the word atom is termed as indivisible. The atoms can not be further broken down.
All atoms are indivisible, indestructible, and unchangeable. Atom of an element cannot be created, divided, destroyed, or split into smaller particles or transformed into atoms of other elements or transformed into other atoms in a chemical reaction. They are simply rearrangement of new compound. Dalton’s atomic theory based this hypothesis on the law of conservation of mass and on centuries of experimental evidence.

1,987.

The processes which return carbon (IV) oxide to the atmosphere include

A.

respiration, decay and combustion

B.

photosynthesis, respiration and transpiration

C.

ozone depletion, combustion and decay

D.

photosynthesis, decay and respiration

Correct answer is A

No explanation has been provided for this answer.

1,988.

A fixed mass of gas has a volume of 92\(cm^3\) at 3ºC. What will be its volume at 18ºC if the pressure remains constant?

A.

15.3cm3

B.

87.3cm3

C.

552.0cm3

D.

97.0cm3

Correct answer is D

(V1/T1) = (V2/T2)
T1 = 3+273 = 276K
∴ (92/276) = (V2/291)
T2 = 18 + 273 = 291K
V2 (92 * 291)/276
= 97.0\(cm^3\)

1,989.

Which of the following chloride would exhibit the least ionic character?

A.

MgCl2

B.

CaCl2

C.

LiCl

D.

AlCl3

Correct answer is D

No explanation has been provided for this answer.

1,990.

Which of the following statement is true of a proton?

A.

The mass of a proton is 1840 times the mass of electron

B.

The total mass of the protons in a particular nucleus is always half the nuclear size

C.

The mass of a proton is one - twelfth the molar mass of carbon

D.

The mass of a proton is 1.0008g

Correct answer is D

No explanation has been provided for this answer.