Molecular Mass

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Molecular Mass: Overview

This topic covers concepts such as Molecular Mass, etc.

Important Questions on Molecular Mass

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Science>Atoms and Molecules>Molecular Mass> Q 1

The formula unit mass of sodium chloride is:

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Science>Atoms and Molecules>Molecular Mass> Q 2

Given the atomic masses of soidum and chlorine as 23 u and 35.5 u respectively. Calculate the formula unit mass of sodium chloride.

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Science>Atoms and Molecules>Molecular Mass> Q 3

The formula unit mass of sodium chloride is _____ (58.5 u/32.5 u).

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Science>Atoms and Molecules>Molecular Mass> Q 4

The formula unit mass of 58.5 u is of which of the following compounds?

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Science>Atoms and Molecules>Molecular Mass> Q 5

Calculate the formula unit mass of sodium chloride.

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Science>Atoms and Molecules>Molecular Mass> Q 6

Hydrogen is an important gas that is used for many chemical processes. It is often obtained by reacting methane $({CH}_{4})$ with steam in the following reaction.

${CH}_{4} + H_{2} O \to CO + 3 H_{2}$

Using the periodic table, calculate the relative formula mass of the methane and water.

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Science>Atoms and Molecules>Molecular Mass> Q 7

Chlorofluorocarbons (or CFCs) are chemicals that destroy the ozone in the atmosphere. A common CFC has a chemical formula ${CCl}_{2} F_{2}$ . Using the table below, what is the relative formula mass of ${CCl}_{2} F_{2}$ ?

Chemical symbol	Element	Relative atomic mass
$C$	Carbon	$12$
$Cl$	Chlorine	$35.5$
$F$	Fluorine	$19$

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Science>Atoms and Molecules>Molecular Mass> Q 8

Complete the following table.

Element	Atomic mass	Mass in grams	GAM	No. of atoms
Carbon	$12$	$12 g$	$1 GAM$	$6.022 \times 10^{23}$
Oxygen	$16$	$12 g$	$1 GAM$	$6.022 \times 10^{23}$
Nitrogen	$14$	_____	$1 GAM$	_____
Chlorine	$35.5$	_____	_____	$6.022 \times 10^{23}$

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Science>Atoms and Molecules>Molecular Mass> Q 9

Calculate the number of GMM present in $96 g$ oxygen?

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Science>Atoms and Molecules>Molecular Mass> Q 10

Complete the following word equation:

$N_{2} + 3 H_{2} \to 2 {NH}_{3}$

(The atomic mass of nitrogen is $14 amu$ and that of hydrogen is $2 amu$ )

$1$ mole of nitrogen(_____ $g$ ) + $3$ moles of hydrogen ( _____ $g$ ) $\to$ $2$ moles of ammonia (_____ $g$ ).

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Science>Atoms and Molecules>Molecular Mass> Q 11

The gram molecular mass of oxygen molecule is

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Science>Atoms and Molecules>Molecular Mass> Q 12

What is the value of Avogadro’s number?

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Science>Atoms and Molecules>Molecular Mass> Q 13

The formula unit mass of sodium chloride is _____.

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Science>Atoms and Molecules>Molecular Mass> Q 14

_____ is considered internationally a standard way to express large number of chemical units.

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Science>Atoms and Molecules>Molecular Mass> Q 15

Which of the following has the maximum number of atoms?

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Science>Atoms and Molecules>Molecular Mass> Q 16

Which of the following elements has the same molecular mass as its atomic mass?

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Science>Atoms and Molecules>Molecular Mass> Q 17

_____ of substance, contains $6.023 \times 10^{23}$ atoms or molecules.

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Science>Atoms and Molecules>Molecular Mass> Q 18

Which of the following weighs the most?

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Science>Atoms and Molecules>Molecular Mass> Q 19

Column I	Column II
( $i$ ) $9.033 \times 10^{24}$ atoms	(A) $46$ g of $He$
( $ii$ ) $2$ moles of $Na$	(B) $15$ moles
( $iii$ ) $11.2$ L of $O_{2}$ at STP	(C) $3.011 \times 10^{23}$ molecules
( $iv$ ) $22$ g of ${CO}_{2}$	(D) $16$ g

Molecular Mass

Molecular Mass: Overview

Important Questions on Molecular Mass

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