MCQ D – more than 2 miscible fluids in a liquid mixture, different b.p. A – look for horizontally matching dots C – always remove the solid through filtration first, then evaporate most of the water away (evaporation), before letting it cool to crystalize (crystalization). B B – evaporation is out, because more than 1 liquid can be driven off by heat, and more than 1 solid solute can remain in the residue. Filtration is out because any number of solutes can be present in the filtration, and any number of insoluble solids can be in the residue.
Q6 Filtration. Barium nitrate. (NAME means state chemical name.) Nitric acid AND sulfuric acid (because excess of it is used!) X: residue; Y: filtrate.
Q7 Thermometer; condenser; conical flask OR distilling flask. To ensure the boiling process is smooth. It is to ensure the lower end of the condenser is always the coolest, hence maximize efficiency of condensation and the yield of distillate. Because the thermometer measures the temperature of pure steam, which is at 100oC.
Q8 The whole idea..
Q8 Set up the apparatus as shown. Use the matches to light up the candles and heat up seawater in the metal container. Pure steam will rise, and when it meets the colder surface of the metal tray, it will condense back into liquid water, and slide down the tray into the another container.
Q8 A and D Dye B, because it stays on the starting line OR it is not travelling forward with the solvent. Because it contains dye A, which is harmful to people. - draw the starting line in pencil. OR – ensure the solvent level is beneath the starting line. OR – wear gloves when handling the dyes. OR other valid answers (check with me.)
Q9 Magnetic attraction method is using magnets to separate magnetic materials such as iron from non-magnetic materials. Filtration method is separating insoluble solid from liquid in a solid-liquid mixture, by letting the mixture pass through a filter.
Q10 Use a magnet to attract and remove all the nickel pellets. Add enough water to the mixture, and scoop up all the floating Styrofoam beads. Stir to ensure all salt is dissolved, and filter the mixture. Wash the residue with lots of distilled water and dry between filter paper to collect the sand. Heat the filtrate in an evaporating dish and evaporate it to dryness. The residue is table salt.