Experiment query!

Please help me out on this. I need immediate answers if thats possible. I'll really appreciate any help. This query is from a friend who emailed me:

The experiment was basically to find the percentage purity of three different brands of iron tablets. I did this through titration with potassium permanganate. I also had to do colorimetry with different concentrations of the iron solution and with ammonium thiocyanate (makes solution go red). I also had to do colorimetry changing the thiocyanate concentration and by keeping the iron concentration the same - this would allow me to find the order of reaction. However, i was unable to get these results and so i have had to make them up. I was wondering what the effect of changing the concentrations of thiocyanate and iron would have on the rate - would it double the rate of reaction.

In this experiment iron is present as Fe3+ . i have made up the colorimetry results ( i have roughly made the rate double when the concentration of the chemicals are doubled) - making the overall rate of reaction second order.

I appreciate your help.

Thank you in advance!