Page 10 25. Which line in the table shows the properties of the most suitable solvent to extract caffeine from an aqueous solution of tea? A Caffeine is more soluble in the solvent than it is in the tea solution. The solvent is immiscible in the tea solution. B Caffeine is more soluble in the solvent than it is in the tea solution. The solvent is miscible in the tea solution. C Caffeine is less soluble in the solvent than it is in the tea solution. The solvent is miscible in the tea solution. D Caffeine is less soluble in the solvent than it is in the tea solution. The solvent is immiscible in the tea solution. 26. A series of titrations was performed to determine the concentration of vitamin C in a brand of fruit juice. A standard solution of the fruit juice was prepared and titrated with iodine solution. Which of the following would be a suitable control experiment for this analysis? A Titrate more samples from the same carton of fruit juice. B Titrate a solution of pure vitamin C of known concentration. C Titrate more samples from the standard solution of fruit juice. D Titrate a sample from a different carton of the same brand of fruit juice. 27. Ba(OH)2(aq) + Na2SO4(aq) ↓ BaSO4(s) + 2NaOH(aq) 50 cm3 of 0·010 mol l−1 barium hydroxide solution were added to 50 cm3 of 0·010 mol l−1 sodium sulfate solution. The concentration of sodium hydroxide, in mol l−1, in the resulting solution is A 0·0010 B 0·010 C 0·020 D 0·10.