Competitive Exams Question Papers

Indian Army M.E.R Soldier Technical Recruitment Test – Solved Original Question Paper with Answer – Part 4 – 19-08-2017

Indian Army M.E.R Soldier Technical Recruitment Test – Solved Original Question Paper with Answer – Part 4 – 19-08-2017

31. Which one of the following is not a physical change ?
A) Evaporation of water
B) Sublimation of NH4Cl
C) CO2 turns lime water milky
D) Distillation of alcohol

Explanation : Ans : C
Physical changes are changes affecting the form of chemical substance, but not chemical composition. CO2 turns lime water Milky is a chemical change.

32. Photochemical reaction takes place in the presence of
A) heat B) light radiation
C) water D) air

Explanation : Ans : B
Photochemical reaction, a chemical reaction initiated by the absorption of energy in the form of light.

33. A chemical change does not occur when
A) iron rusts
B) turning of lime water milky by CO2
C) burning of gases
D) water boils

Explanation : Ans : D
When water boils, the water turns from a liquid to gas. This does happen with a simple phase change, but it does not requires a chemical reaction.

34. Reactions accompanied by absorption of heat are called
A) endothermic
B) exothermic
C) photochemical
D) chemical

Explanation : Ans : A
The term endothermic process describes, the process or reaction in which the system absorbs energy from the surrounding.

35. Which one of the following is not a physical property of matter?
A) Density
B) Combustibility
C) Solubility
D) Electrical conductivity

Explanation : Ans : B
The tendency of a substance to burn is an example of a chemical property. Flammable or combustible is an important chemical property.

36. Neutrons can be found in atoms of all elements except
A) Carbon B) Helium
C) Hydrogen D) Neon

Explanation : Ans : C
Hydrogen is a group 1 element. Hydrogen atom has a nucleus consisting of a proton, electron and has no neutron.

37. The smallest particle in which matter can exist is called
A) An ion B) An atom
C) A molecule D) An element

Explanation : Ans : B
An atom is the smallest particle of an element, having the same chemical properties.

38. Which of the following is not an element?
A) Aluminium B) Mercury
C) Gold D) Water

Explanation : Ans : D
Water is a molecule. It is not a element because it is made from a atoms of one element – oxygen and two atoms of hydrogen.

39. Isotopes of an element have
A) The same atomic number
B) The same atomic weight
C) The same atomic weight but different atomic number
D) Different atomic number

Explanation : Ans : A
Isotopes are atoms of the same element having the same number of protons (atomic number). But different number of neutrons.

40. Which of the following is a compound?
A) Milk B) Gold
C) Coal D) Water

Explanation : Ans : D
The chemical formula of water is H2O, which means each molecule of water consists of one oxygen atom chemically bonded to two hydrogen atoms. Thus water is a compound.

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