Statement 1: a dye with an Rf R_f\,Rf value of 0.80 spends more of its time dissolved in the solvent than a dye with an Rf R_f\,Rf value of 0.20
Statement 2: a sample that gives a single spot in one solvent must be a pure substance
Statement 3: if the solvent were allowed to travel further up the paper, the Rf R_f\,Rf value of each dye would stay the same
Which statements are correct?
1 only
1 and 3 only
2 and 3 only
1, 2 and 3
107 exam-style questions on Edexcel GCSE Chemistry 3.2 Methods of separating and purifying substances, covering 3.2.1 Pure substances and mixtures, 3.2.2 Techniques for separating mixtures, 3.2.3 Paper chromatography and Rf values, and 3.2.4 Making water potable. Each one has a worked solution and a mark scheme showing where the marks go.