If I was using this method (http://www.rsc.org/learn-chemistry/wiki/Expt:The_effect_of_concentration_on_reaction_rate) however used pre-prepared concentrations of sodium thiosulfate solution, which intervals would be more suitable, 0.1M, 0.2M, 0.3M, 0.4M or 0.5M, 1M, 1.5M and 2M? Also, what concentration of Hydrochloric acid should be used (I've seen a variety of suggestions elsewhere). This is for a secondary school practical. Thank you.

If I was using this method (https://edu.rsc.org/resources/the-effect-of-concentration-on-reaction-rate/743.article) however used pre-prepared concentrations of sodium thiosulfate solution, which intervals would be more suitable, 0.1M, 0.2M, 0.3M, 0.4M or 0.5M, 1M, 1.5M and 2M? Also, what concentration of Hydrochloric acid should be used (I've seen a variety of suggestions elsewhere). This is for a secondary school practical. Thank you.