Test: Mole Concept

# Test: Mole Concept - Class 9

Test Description

## 15 Questions MCQ Test Online MCQ Tests for Class 9 - Test: Mole Concept

Test: Mole Concept for Class 9 2023 is part of Online MCQ Tests for Class 9 preparation. The Test: Mole Concept questions and answers have been prepared according to the Class 9 exam syllabus.The Test: Mole Concept MCQs are made for Class 9 2023 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for Test: Mole Concept below.
Solutions of Test: Mole Concept questions in English are available as part of our Online MCQ Tests for Class 9 for Class 9 & Test: Mole Concept solutions in Hindi for Online MCQ Tests for Class 9 course. Download more important topics, notes, lectures and mock test series for Class 9 Exam by signing up for free. Attempt Test: Mole Concept | 15 questions in 15 minutes | Mock test for Class 9 preparation | Free important questions MCQ to study Online MCQ Tests for Class 9 for Class 9 Exam | Download free PDF with solutions
 1 Crore+ students have signed up on EduRev. Have you?
Test: Mole Concept - Question 1

### The total number of atoms represented by the compound CuSO4.5H2O is -

Detailed Solution for Test: Mole Concept - Question 1

Copper atom(s) = 1
Sulfur atom(s) = 1
Oxygen atoms = 4 + 5 = 9
Hydrogen atoms = 10

Total atoms = 1 + 1 + 9 + 10 = 21

∴ There are total 21 atoms in CuSO₄·5H₂O (also called blue vitriol).

Test: Mole Concept - Question 2

### If 12 grams of carbon has n atoms, then the number of atoms in 12 grams of magnesium will be:

Detailed Solution for Test: Mole Concept - Question 2

C =  12 g = 1 mole
1 mole = 24 g = n atoms
1 g = (n  * 12) / 24
1 g  =  n /2

Test: Mole Concept - Question 3

### What is the value of Avogadro’s number?

Detailed Solution for Test: Mole Concept - Question 3

Avogadro’s number, number of units in one mole of any substance (defined as its molecular weightin grams), equal to 6.022140857 × 1023.

Test: Mole Concept - Question 4

1 mole of water molecules has:

Detailed Solution for Test: Mole Concept - Question 4

Water (H2O) is made from 2 atoms of hydrogen and 1 atom of oxygen. A mole of water molecules would be 2 moles of hydrogen atoms plus 1 mole of oxygen atoms.

Test: Mole Concept - Question 5

How many atoms does one mole of Phosphorus molecule contain?

Detailed Solution for Test: Mole Concept - Question 5

Phosphorus exists as a tetratomic molecule i.e.  Pmolecule. Thus, 1 mole of P4 = 4 × 6.022 × 1023 atoms

Test: Mole Concept - Question 6

Which of the following pair of elements represents a mole ratio of 1:1?

Detailed Solution for Test: Mole Concept - Question 6

14 g of nitrogen = gram atomic mass of nitrogen = 1 mole of nitrogen atoms

24 g of magnesium = gram atomic mass of magnesium = 1 mole of magnesium atoms

So, mole ratio = 1:1

Test: Mole Concept - Question 7

The number of moles of oxygen atoms in two moles of nitric acid is:

Test: Mole Concept - Question 8

Identify the symbol used to represent Avogadro’s number.​

Detailed Solution for Test: Mole Concept - Question 8

Avogadro's number,NA,is defined as the number of atoms in 12 gram of carbon-12 atoms in their ground state at rest.

By definition it is related to the atomic mass constant  mu  by the relation.

Avogadro's number are defined in terms of the atomic mass constant (one twelfth of the mass of a 12C atom).

Avogadro's constant and number have by definition the same numerical value. In practice the two terms are used interchangeably.

Test: Mole Concept - Question 9

The mass of 0.5 moles of Water molecules is:(Atomic mass, H =1; O = 16)

Detailed Solution for Test: Mole Concept - Question 9

Given Data:
Mass of Water = ?
no. of moles = 0.5
Molar mass of H₂O = 2(1) + 16 = 18 g/mol

Formula to be Used:
No. of moles = Given Mass/Molar mass

Solution:
No. of moles = Mass of Water/Molar mass
0.5 = Mass of Water/18
Mass of Water = 0.5*18
Mass of Water = 9g

Test: Mole Concept - Question 10

The number of moles present in 52g of He(Atomic mass, He = 4) are:

Detailed Solution for Test: Mole Concept - Question 10

no of moles = mass in gram / molecular mass

no. of moles = 52/4 =13

Test: Mole Concept - Question 11

How many atoms are present in SO42- ion ?

Detailed Solution for Test: Mole Concept - Question 11

A sulphate ion (SO42-) contains one sulphur atom and four oxygen atoms. Therefore there are 5 atoms in a sulphate ion. In the ammonium ion (NH4+) there is one nitrogen atom and four hydrogen atoms. So, this ion also contains 5 atoms.

Test: Mole Concept - Question 12

Calculate the relative molecular mass of H2S.

Detailed Solution for Test: Mole Concept - Question 12

Atomic mass of hydrogen = 1 a.m.u.

Atomic mass of Sulphur = 32 a.m.u.

Thus, the molecular mass of hydrogen sulphide, which contains two atoms of hydrogen and one atom of sulphur is = 2 × 1 + 1 × 32 = 34 a.m.u.

Test: Mole Concept - Question 13

If atomic mass of sodium is 23 a.m.u., then the mass of 3.01 x 1023 sodium atoms is:

Detailed Solution for Test: Mole Concept - Question 13

Mass of 6.022 X 10 23 atoms (1 mole) of sodium = 23 g Test: Mole Concept - Question 14

The atomic mass of calcium is 40. Calculate the number of moles in 16 grams of calcium.

Detailed Solution for Test: Mole Concept - Question 14

Number of moles of Ca :-
n = Given mass in grams / molar mass
=   16 / 40
=   0.4 mole.

Test: Mole Concept - Question 15

One mole of molecules may not be equal to:​

Detailed Solution for Test: Mole Concept - Question 15

- The mole allows scientists to calculate the number of elementary entities (usually atoms or molecules) in a certain mass of a given substance.

- Avogadro’s number is an absolute number: there are 6.022x10^23 elementary entities in 1 mole. This can also be written as 6.022x10^23 mol-1.

- The mass of one mole of a substance is equal to that substance’s molecular weight. For example, the mean molecular weight of water is 18.015 atomic mass units (amu), so one mole of water weight 18.015 grams.

## Online MCQ Tests for Class 9

399 tests
Information about Test: Mole Concept Page
In this test you can find the Exam questions for Test: Mole Concept solved & explained in the simplest way possible. Besides giving Questions and answers for Test: Mole Concept, EduRev gives you an ample number of Online tests for practice

399 tests