How can you calculate molecular weight?

Answer 1

You will need to use the chemical formula of the compound and the average atomic masses from the periodic table to calculate molecular mass .

Let's look at the example of water. I'll round average atomic masses to two places beyond the decimal. You should adjust your rounding based on your teacher's preferences.

#H_2O# = two atoms of H and one atom O in a single molecule

H = 1.01 (use the average atomic mass from the periodic table)
O = 16.00

To find molecular weight:
H = 1.01 x 2 = 2.02 (have to multiply by two since water has two hydrogen atoms)
O = 16.00 x 1 = 16.00

The total molecular weight is 18.02 - this was found by adding the total mass from H with the total mass from O.

This will also be the molar mass of water

Here are a couple more examples:

Hope this helps

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Answer 2

Natalie Anton

To calculate the molecular weight of a compound, add up the atomic weights of all the atoms in its chemical formula.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.