Chemistry: The Mole Concept and Conversions

Amedeo Avogadro is known for devising a method to count atoms and ______.

Avogadro's number is represented by the symbol ______.

One mole of a substance contains ______ particles.

The mass of one mole of an element is equal to its relative atomic mass in ______.

One mole of sodium has a mass of ______ grams.

The mass of three moles of aluminium can be calculated as 27 ______ 3.

To find the relative molecular mass of a compound, you need to sum up the ______ atomic masses of all its atoms.

One mole of oxygen is equivalent to a mass of ______ grams.

The relative molecular mass of water (H2O) is calculated to be ______.

One mole of hydrated copper(II) sulfate (CuSO4.5H2O) weighs ______ grams.

To convert grams of an element to moles, you divide the mass of the element by its ______.

In 36 grams of carbon atoms, there are ______ moles.

The relative molecular mass of sulfuric acid (H2SO4) is calculated to be ______.

The number of moles of a compound is calculated by dividing the mass of the compound by its ______.

One mole of a substance contains approximately ______ particles.

There are approximately ______ moles of water in 117 grams of water.

The Mole Concept

Avogadro developed a method for counting atoms and molecules.
If elements are weighed in proportions equal to their relative atomic masses, the same number of atoms will result.
Avogadro's number (or Avogadro's constant) is 6 x 10²³ and is represented by the symbol 'L'.
One mole of a substance contains 6 x 10²³ particles of that substance.
The mass of one mole of an element is equal to its relative atomic mass in grams.

Converting Moles to Grams

Examples of elements and their masses are provided (e.g., Carbon = 12 g, Magnesium = 24 g, Silver = 198g).
The relative atomic mass of elements like Hydrogen (H), Carbon (C), Nitrogen (N), Oxygen (O), etc. are given.
One mole of Sodium is 23g and one mole of Oxygen is 35.5g.
The mass of three moles of Aluminum atoms can be calculated.
- 1 mole of Al = 27 g
- 3 moles of Al = 81 g

Converting Grams to Moles

Determining the number of moles from the mass of a given element is explained.
The mass of one mole of a compound is calculated by adding up the relative atomic masses of all component elements.
Calculation example including hydrated copper (II) sulfate CuSO₄.5H₂O.

Calculations involving Avogadro's Number

One mole of a substance contains 6 x 10²³ particles (atoms or molecules) of that substance.
This concept is used in calculations:
- Converting Moles to Number of Atoms or Molecules (e.g. 0.25 moles of Sodium have 1.5 x 10²³ atoms.)
- Converting Grams to Number of Atoms or Molecules (e.g. Calculate the number of atoms in 28.75 g of Sodium, answer = 7.5 x 10²³ atoms).
- Converting Numbers of Atoms or Molecules to Moles (e.g How many moles of aluminium atoms are there in 9 x 10²² atoms of aluminium, answer = 0.15 mole)
- Converting Numbers of Atoms or Molecules to Grams (Calculate how many grams of zinc are present in 3 x10²⁰ atoms of zinc, answer = 0.0325 g).

This quiz covers the fundamental concepts of the mole, including Avogadro's number and methods for converting moles to grams and vice versa. You will encounter examples related to different elements and their respective masses. Test your knowledge on how to calculate moles and grams effectively.