<span>Compounds are composed of different elements in a fixed proportions. For example, 1 atom of oxygen (O) combines with 2 atoms of hydrogen (H) to form one molecule of water (H2O) compound. Similarly other numbers of atoms would produce other chemical compounds. Even adding 1 more atom of oxygen would convert the water (H2O) into hydrogen peroxide(H2O2). Even if we were only to list the ones we know there are over 20 million known compounds.

In order to list all possible compounds such a table would rapidly become combinatoric nightmare of such size that it would not be practical to use even with a computer database and it would consist of over 100 billion possible compounds containing only H, C, O and N.

Creating a table to handle all possible elements would mean a table of many trillions of compounds.</span>

4 0

2 years ago

The answer to question 2

Bad White [126]

Answer:

Explanation:

You will need a chemical equation with masses and molar masses, so let’s gather all the information in one place.

$M_{r}$ : 258.21 18.02

KAl(SO₄)₂·xH₂O ⟶ KAl(SO₄)₂ + xH₂O

Mass/g: 4.74 2.16

Step 1. Calculate the mass of the KAl(SO₄)₂.

Mass = 4.74 g – 2.16 g = 2.58 g.

Step 2. Calculate the moles of each product.

$\text{Moles of KAl(SO}_{4})_{2} = \text{2.58 g} \times \frac{\text{1 mol} }{\text{258.21 g}} = 9.992 \times 10^{-3} \text{ mol}$

$\text{Moles of H}_{2}\text{O} = \text{2.16 g} \times \frac{\text{1 mol} }{\text{18.02 g}} = \text{ 0.1200 mol}$

Step 3. Calculate the molar ratio of the two products.

$\frac{\text{Moles of KAl(SO}_{4})_{2}}{\text{Moles of H}_{2}\text{O}} = \frac{ 9.992 \times 10^{-3} \text{ mol}}{\text{ 0.1200 mol} } = \frac{1 }{12.01} \approx \frac{ 1}{ 12}$

1 mol of KAl(SO₄)₂ combines with 12 mol H₂O, so x = 12.

3 0

3 years ago