Molecular Mass and Mole Concept
Molecular Mass and Mole Concept: Overview
This topic covers concepts, such as, Molecular Mass, Calculation of Molecular Mass of Compounds, Calculation of Number of Particles from given Mass of Molecules & Gram Molecular Mass etc.
Important Questions on Molecular Mass and Mole Concept
The formula unit mass of sodium chloride is:

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

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

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

Calculate the formula unit mass of sodium chloride.

Hydrogen is an important gas that is used for many chemical processes. It is often obtained by reacting methane with steam in the following reaction.
Using the periodic table, calculate the relative formula mass of the methane and water.

Chlorofluorocarbons (or CFCs) are chemicals that destroy the ozone in the atmosphere. A common CFC has a chemical formula . Using the table below, what is the relative formula mass of ?
Chemical symbol | Element | Relative atomic mass |
Carbon | ||
Chlorine | ||
Fluorine |

of water and of oxygen gas contain same number of molecules.

Complete the following table.
Element | Atomic mass | Mass in grams | GAM | No. of atoms |
Carbon | ||||
Oxygen | ||||
Nitrogen | _____ | _____ | ||
Chlorine | _____ | _____ |

Calculate the number of GMM present in oxygen?

Complete the following word equation:
(The atomic mass of nitrogen is and that of hydrogen is )
mole of nitrogen(_____) + moles of hydrogen ( _____) moles of ammonia (_____).

The gram molecular mass of oxygen molecule is

What is the value of Avogadro’s number?

Determine the molecular mass of .

The formula unit mass of sodium chloride is _____.

Calculate the percentage of Oxygen in water.

Calculate the percentage of nitrogen in Urea .

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

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

_____ of substance, containsatoms or molecules.
