State FIVE properties of Transition Metals. Define the following, with (2) examples each: (i) Precious metals (ii) Base Metals. State FOUR physical properties of metals

The molar mass of sodium (Na) is approximately $22.99 \text{ g/mol}$.
The molar mass of oxygen (O) is approximately $16.00 \text{ g/mol}$.
The molar mass of hydrogen (H) is approximately $1.01 \text{ g/mol}$.

$$\text{Molar mass of NaOH} = 22.99 + 16.00 + 1.01 = 40.00 \text{ g/mol}$$

Given mass of NaOH = $7.56 \text{ g}$.

$$\text{Moles of NaOH} = \frac{\text{Mass}}{\text{Molar mass}} = \frac{7.56 \text{ g}}{40.00 \text{ g/mol}}$$ $$\text{Moles of NaOH} = 0.189 \text{ mol}$$

The volume of the solution is given as $1 \text{ litre}$.
Molarity (M) is defined as moles of solute per litre of solution.

$$\text{Molarity} = \frac{\text{Moles of NaOH}}{\text{Volume of solution (L)}} = \frac{0.189 \text{ mol}}{1 \text{ L}}$$ $$\text{Molarity} = 0.189 \text{ M}$$

The molarity of the solution is $\boxed{\text{0.189 M}}$.