Question

Question 1 Status: Not yet answered | Points possible: 1.00 Which property is the basis of the purification technique recrystallization? Select one: Molecular weight O Polarity O Color Solubility

Answer 1

1. Solubility is the basis of the purification technique recrystallisation.

( The principle behind recrystallisation is that the amount of solute that can be dissolved by a solvent increases with temperature .)

2. (24×2) g of Mg reacts with 32 g of O₂ to form (2×24 + 32) g = 80 g MgO .

Or, 2 mol of Mg reacts with 1 mol of oxygen to form 2 mol of MgO.

Here, 0.0575 mol of Mg reacts with 0.0853 g of Oxygen to form 0.0575 mol of MgO( as Mg is the limiting reactant here).

3. True statements about limiting reactant are----

• There will be an excess of other reactants at the end of the reaction.

• The limiting reactant is completely used up in the reaction.

• The limiting reactant dictates the amount of product.

• The limiting reactant is always the same for a given reaction.