题目
单项选择题
A mixture of aspirin and caffeine was dissolved in ethanol and spotted onto a thin layer chromatography plate. After the chromatogram was developed it was observed that the aspirin had travelled almost to the top of the plate, whereas the caffeine was much lower. Compared to caffeine, aspirin is adsorbed (attracted to)
选项
A.a. more strongly onto the stationary phase and has a larger Rf value.
B.b. more strongly onto the stationary phase and has a smaller Rf value.
C.c. less strongly onto the stationary phase and has a larger Rf value.
D.d. less strongly onto the stationary phase and has a smaller Rf value.
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