Question

A sample of an ionic compound contains 2.82g Na ,4.35 g Cl and 7.83g O . The empirical formula of this compound is

Answer 1

Answer:

A sample of an ionic compound contains 2.82g Na ,4.35 g Cl and 7.83g O . The empirical formula of this compound is

Explanation:

You know that your compound contains 2.82 g of sodium, 4.35 g of chlorine, and 7.83 g of oxygen.

What you do next is use each element's molar mass to try and find how many moles of each you get in that sample of the compound.

In this case, you have

For Na: 2.82g23.0gmol=0.1226 moles Na

For Cl: 4.35g35.45gmol=0.1227 moles Cl

For O: 7.83g16.0gmol=0.4894 moles O

Now, the reason you divide these numbers by the smallest one is so that you ahve an idea of the mole ratios that exist between the elements that make up the compound.

In this case, you have

For Na: 0.1226moles0.1226moles=1

For Cl: 0.1227moles0.1226moles=1.001

For O: 0.4894moles0.1226moles=3.992

So, what do you do with the numbers that hav a decimal? You round them to the nearest integer.

For 1.001, the nearest integers is 1, so you have

For Cl: 1.001≈1

For 3.992, the nearest integer is 4, so you have

For O: 3.992≈4

This means that the empirical formula, which tells you what the smallest integer ratio of atoms you get in a compound, will be

Na1Cl1O4