Chemistry (NTSE Stage-2 (National-Level) Scholastic-Aptitude & Language Comprehension): Questions 4 - 6 of 63

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Question number: 4

» Chemistry » Physical and Chemical Changes

Appeared in Year: 2013

MCQ▾

Question

A silvery white metal X reacts with water at room temperature to produce a water soluble compound Y and a colorless gas Z. The reactions are highly exothermic and the Z catches fire immediately during the reaction. The solution of Y in water on reacting with stoichiometric amount of dilute solution of hydrochloric acid gives a solution of pH = 7.0 the compounds X, Y and Z respectively are

Choices

Choice (4) Response

a.

Na,NaOHandH2

b.

Ag,AgOHandH2

c.

Al,AI(OH)3andH2

d.

K,KCIandH2

Question number: 5

» Chemistry » Structure of Atom

Appeared in Year: 2013

MCQ▾

Question

An element X has 7 electrons in its L shell. What is true about the element X?

I. It belongs to period 9 of modern periodic table.

II. Its atom contains 9 protons.

III. It has a valency of 7.

IV. Its atoms can accept an electron to acquire noble gas configuration.

Choices

Choice (4) Response

a.

II and III

b.

II and IV

c.

III and IV

d.

I and II

Question number: 6

» Chemistry » Physical and Chemical Changes

Appeared in Year: 2013

Assertion-Reason▾

Assertion (Ꭺ)

Reactivity of aluminum decreases when it is dipped in nitric acid.

Reason (Ꭱ)

a protective layer of aluminum nitrate is formed when aluminum is dipped in nitric acid.

Choices

Choice (4) Response

a.

Both Ꭺ and Ꭱ are false

b.

Both Ꭺ and Ꭱ are true but Ꭱ is NOT the correct explanation of Ꭺ

c.

Ꭺ is true but Ꭱ is false

d.

Ꭺ is false but Ꭱ is true

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