In an osmosis experiment, potato strips, each 5 cm in length were left in salt solutions of different concentrations.The table shows the lengths of the strips after 30 minutes.Which salt solution was the least concentrated, A, B C or D?I DON'T KNOWSUBMIT ANSWER

Miranda makes four different solutions by mixing salt and water as shown in the table below.Solution Weight of Salt Volume of Water1 5 g 50 mL2 5 g 100 mL3 5 g 150 mL4 5 g 200 mLWhich solution has the lowest concentration? A. solution 3 B. solution 1 C. solution 4 D. solution 2

Some students set up an experiment using osmosis to find the concentration of sucrose solution in potato cell sap. They used discs of potato cut to the same size and weighing approximately 10 gms. The discs were put into each of five beakers.2. (a) (i) After two hours they reweighed the discs after carefully blotting them first. Why did the students blot the potato before weighing it? ______________________________________________________________ ______________________________________________________________ (1) (ii) Their results are shown in the table below.Beaker 1 Beaker 2 Beaker 3 Beaker 4 Beaker 5 Final mass in g 13.0 12.2 9.0 7.9 7.3 Initial mass in g 10.0 10.6 10.0 10.1 10.4 Page 3 of 16It improves the rate of diffusion as there is less distance for the exchange of gases to occur. Another is that there will be no blockages in the capillaries as there are not lots of blood cells that can cause blockages.It also helps in maintaining blood pressure The students calculated the % gain or loss in mass of potato. Complete this table of results for Beakers 2, 4 and 5.Beaker 1 Beaker 2 Beaker 3 Beaker 4 Beaker 5 13 – 10.0 = 3.09.0 – 10.0 = –1.0 = –10%Gain in mass = 30%Loss in mass = 10%(3) (b) (i) Draw a graph of % Gain or Loss in mass against sucrose concentration.(3) Page 4 of 16(ii) Use the graph to find the concentration of potato cell sap. Concentration of cell sap = _____________________ % sucrose solution (1) (iii) Explain in terms of osmosis how you chose this value. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ (2) (Total 10 marks) (a) Some scientists investigated the rates of absorption of different sugars by the small intestine. In one experiment they used a piece of normal intestine. In a second experiment they used a piece of intestine poisoned by cyanide. Cyanide is poisonous because it prevents respiration. The results are shown in the table.Relative rates of absorption SugarNormal intestine Intestine poisoned by cyanide Glucose1.000.33 Galactose1.100.53 Xylose0.300.31 Arabinose0.290.29 3. (i) Name two sugars from the table which can be absorbed by active transport. 1. ____________________________________________________________ 2. ____________________________________________________________ (1) Page 5 of 16(ii) Use evidence from the table to explain why you chose these sugars. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ (3) (b) All of the sugars named in the table can be absorbed by diffusion. Explain how information from the table provides evidence for this. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (Total 6 marks)

Three salt solutions are to be used in an experiment, a 0.5 g/dm3 solution (solution 1), a 1.5 g/dm3 solution (solution 2) and a 2.5 g/dm3 solution (solution 3). Which solution is the most concentrated?

Three salt solutions are to be used in an experiment, a 0.5 g/dm3 solution (solution 1), a 1.5 g/dm3 solution (solution 2) and a 2.5 g/dm3 solution (solution 3). Which solution will contain the fewest salt particles in a particular volume?solution 2solution 3solution 1

Four salt solutions are created using different amounts of salt and water, as shown.Solution Salt(tablespoon) Water(mL)P 2 200Q 2 100R 1 200S 1 100Which solution has the highest concentration, and why?ResponsesSolution P; it has more salt and water compared to the other solutions.Solution P; it has more salt and water compared to the other solutions.Solution Q; it has more salt with a smaller amount of water compared to the other solutions.Solution Q; it has more salt with a smaller amount of water compared to the other solutions.Solution R; it has less salt with a larger amount of water compared to the other solutions.Solution R; it has less salt with a larger amount of water compared to the other solutions.Solution S; it has less salt and water compared to the other solutions.