3 How many moles in each of the following? a 12 mg of magnesium __ __ .......................-... __ __ 4 What is the mass of each of the following? a 0.100 moles of calcium hydroxide __ __ b 0.025 moles of aluminium sulfate __

Firstly, to find out the number of moles, we need to use the formula: \[ n (moles) = m (mass)/(Mm (Molar Mass) Secondly, for Mass of certain chemicals by given moles, we can utilize this formula:\[ m (mass) = n (moles) * Mm (Molar Mass)Let us identify the molar mass of each compound. - Magnesium (Mg): Molar mass is 24.305 g/mol- Oxygen (O): Molar mass is 15.999 g/mol. Note that because oxygen is a diatomic, its molar mass is technically 15.999 g/mol * 2 = 31.998 g/mol. - Calcium Hydroxide (Ca(OH)2): Molar mass is 74.093 g/mol- Aluminium Sulfate (Al2(SO4)3): Molar mass is 342.156 g/molNow to start Q3:a) We know that 12 mg is the same as 0.012g. So, our calculation becomes: / 24.305 g/mol b) Remember that when dealing with kilograms, you must first convert back to grams. 8.0 kg becomes 8000g. The formula becomes: n = 8000g/ 31.998 g/molAnd for Q4: a) m = 0.100 moles * 74.093 g/Molb) m = 0.025 moles * 342.156 g/Mol