Question

Reaction 1: Nitration HNO3 NO2 H2SO4, H20 NO2 toluene NO2 ortho meta para Procedure for Reaction 1: 1) To a stirred solution of 3 mL (44.7 mmoles) 67 % HNO3 in 3.75 mL of water, H2SO4 (9 mL) was slowly added at 10-15 °C. 2) This nitrating solution was added dropwise with vigorous stirring to 4 mL (37.5 mmoles) of toluene while cooling in ice-water in order to maintain the reaction temperature between 15 and 25 °C. 3) Stirring was continued for 20 minutes at room temperature and the reaction mixture carefully quenched over 15 g of crushed ice. 4) Diethyl ether was added to the aqueous solution and the organic layer was separated. 5) The aqueous layer was extracted with diethyl ether (2 x 10 ml). 6) The organic extracts were combined and washed with 10 % NaOH (3 X 5 mL) and brine (5 ml), dried with anhydrous sodium sulfate and evaporated. 7) A sample was analyzed by gas chromatography in order to determine the ratios of the ortho, meta, and para nitrated products.

Answer 1

1. Organic layer : top one

Aqueous layer : bottom

Since diethyl Ether has less density than water so the top layer will be organic.

in case we need to identify, we will put few crystals of sodium chloride, which due to polar (ionic) nature will directly go into bottom. this confirms that bottom layer is Aqueous because sodium chloride and water are polar compound.

2. According to nernst distribution law, multiple extraction is better than single extraction. on extracting multiple times the extraction efficiency INCREASES.

3. Washing was done with Sodium Hydroxide to remove any traces of acid present.