GCSE / O Levels Chemistry

Aqueous sodium thiosulfate reacts with acid to make a precipitate of sulfur.
NazS2O3(aq) + 2HCI(aq) → 2NaCl(aq) + H20(1) + SO2(g) + S(s)
A student investigates the effect of temperature on the rate of this reaction.
The student:
places a piece of paper with a cross on it below the reaction mixture as shown in the
diagram
measures the time taken for the cross to no longer be seen
repeats the reaction at different temperatures.
50 cm³ aqueous
-sodium thiosulfate
paper with cross-
+ acid
Which apparatus is needed for this investigation?
A balance, pipette, stop-clock
B balance, stop-clock, thermometer
C burette, gas syringe, thermometer
D measuring cylinder, stop-clock, thermometer


Experimental Design | 2020 - M/J - 5070/12 | Q2