Alright! Here’s the explanation without using any equation:
To calculate the number of moles in a given mass, you simply compare the mass of the substance you have with the mass of one mole of that substance, which is called its molar mass.
Steps in words:
- First, find the molar mass of the substance. This is the mass of one mole of that substance and can be determined from the periodic table by adding up the atomic masses of the elements in it.
- Next, take the actual mass of the substance that is given in the problem.
- Finally, divide the given mass by the molar mass. The result tells you how many moles of the substance are present.
For example, if you have a certain mass of water, you first know that one mole of water weighs eighteen grams. If you are given thirty-six grams of water, you compare it with eighteen grams. Since thirty-six is twice eighteen, it means you have two moles of water.
In short: you find moles by comparing the mass you have with the mass of one mole of the substance.