CIE Chemistry (US-0439): Specimen Questions with Answers 60 - 62 of 240

Question number: 60

MCQ▾

Question

What is the balanced chemical equation for the reaction between calcium and water?

Choices

Choice (4) Response

a.

Ca + H2O→CaOH + H2

b.

Ca + H2O→CaOH2 + H2

c.

Ca + 2H2O→CaOH + H2

d.

Ca + 2H2O→CaOH2 + H2

Answer

d.

Explanation

Correct option is D because when calcium react with water then it forms calcium hydroxide and hydrogen gas. So in option D calcium is balanced hydrogen is balanced as well as oxygen is also balanced.

As shown in figure.

Image of balanced chemical equation

Image of Balanced Chemical Equation

Image of balanced chemical equation

Question number: 61

Short Answer Question▾

Write in Short

Explain the term equilibrium mixture

Explanation

The concept of chemical equilibrium was developed after Berthollet found that some chemical reactions are reversible. For any reaction mixture to exist at equilibrium, the rates of the forward and backward (reverse) reactions are equal.

The syringe contains a sample of the equilibrium mixture. The plunger was pulled back reducing the pressure.

Question number: 62

MCQ▾

Question

A compound with the formula has a relative formula mass of .

What is element X?

Choices

Choice (4) Response

a.

Argon

b.

Calcium

c.

Neon

d.

Zirconium

Answer

b.

Explanation

Correct Option is B because have molecular mass so two fluorine have molecular mass and total formula mass is . When then left is and one calcium have molecular mass. So calcium will be correct answer. As shown in the below fluorine atom and one calcium atom form

Image of fluorine atom and one calcium atom form CaF2

Image of Fluorine Atom and One Calcium Atom Form CaF2

Image of fluorine atom and one calcium atom form CaF2