Put it in a beaker. Use a smaller beaker filled half way with ice and water and place in the larger one. It should be about an inch or two above the mixture. Heat over a Bunsen burner and the naphthalene will deposit on the bottom of smaller beaker.
And in this way, nephthalene be separated from the mixture of KBR and sand.
1. In this reaction, 2 moles of nitrogen gas reacts with 3 moles of oxygen gas to give 2 moles of N2O3 gas. 2 nitrogen molecules react with 3 oxygen molecules to give 2 N2O3 molecules. Under STP, one mole of an ideal gas occupies a volume of 22.4 liters. So in this reaction, 44.8 liters of nitrogen gas reacts with 67.2 liters of oxygen gas to give 44.8 liters of N2O3 gas. The total mass of the reactants (N2 and O2) is the same as the total mass of the product (N2O3). This is called mass balance of a chemical reaction.
2. According to the chemical reaction, 3 moles of chlorine gas produces 2 moles of iron(III) chloride. So, to produce 1 moles of iron(III) chloride, 3/2 (1.5) moles of chlorine gas is required. Therefore, to produce 14 moles of iron(III) chloride, 14 x 1.5 = 21 moles of chlorine is needed.
D for sure hope this helps