Difference between revisions of "GCSE Chemistry Required Practical: Calculating Retention Factors"

Revision as of 11:36, 29 January 2019

Use a Chromatography experiment to produce a Chromatogram and calculate the Retention Factors (R_f) for they dyes found within different inks.

Take a piece of chromatography paper of width 6cm and height 10cm.
Using a ruler draw a line with pencil across the width 2cm up from the end.
Add a dot of each unknown sample on the pencil line at 1cm intervals.
Suspend the chromatography paper in a suitable solvent just below the pencil line with most of the paper above the solvent.
Wait until the solvent stops rising up the paper.
Use a ruler to measure the distance that the solvent has traveled up the paper.
Use a ruler to measure the distance that the different dyes have traveled up the paper.
Use the following equation to find the Retention Factor for each dye:

\[R_f = \frac{d_c}{d_s}\]

Where:

d_c = distance moved by the chemical

d_s = distance moved by the solvent

@@ Line 4: / Line 4: @@
 ===Method===
-{| class="wikitable"
+#Take a piece of [[chromatography]] paper of [[width]] 6cm and [[height]] 10cm.
-|-
+#Using a ruler draw a line with pencil across the [[width]] 2cm up from the end.
-|[[File:ChromatographyDiagram.png|center|500px]]
+#Add a dot of each unknown sample on the pencil line at 1cm [[interval]]s.
-|}
+#Suspend the [[chromatography]] paper in a suitable [[solvent]] just below the pencil line with most of the paper above the [[solvent]].
+#Wait until the [[solvent]] stops rising up the paper.
+#Use a ruler to measure the distance that the [[solvent]] has traveled up the paper.
+#Use a ruler to measure the distance that the different [[dye]]s have traveled up the paper.
+#Use the following equation to find the [[Retention Factor]] for each [[dye]]:
+:<math>R_f = \frac{d_c}{d_s}</math>
+:Where:
+:R<sub>f</sub> = [[Retention Factor]]
+:d<sub>c</sub> = distance moved by the [[chemical]]
+:d<sub>s</sub> = distance moved by the [[solvent]]