The final concentration of starch in the solution is calculated to be 3.043 wt%. This is determined by summing the weights of starch (7 grams), ethylene glycol (3 grams), and water (220 grams), and dividing the starch weight by the total weight. The presence of ethylene glycol does not interfere with the concentration as long as calculations are based on weight rather than volume. For starch with a 10% water content, the concentration remains at 3% on a "dry basis," which is the standard in the starch handling industry.
PREREQUISITESChemists, food scientists, and anyone involved in formulation or analysis of starch-based solutions will benefit from this discussion.
3.043 wt%.Cyrus the great said:What is the final concentraion of my starch?
Be careful using the word "volume" unless you really mean it. Keeping it on a weight basis is foolproof. Volumes can combine in unknown ways.Cyrus the great said:So for the final volume of the solution we need to sum up everything we added in the solution (starch, ethylen glycol + water). Then divide amount of starch to the total volume (starch+ethylen glycol+water).Am i right? I got confused because It thought presense of ethylen glycol would interfer the concentration of starch and we will not get 3.043 wt %.
Nope; your method of getting wt% is correct.Cyrus the great said:So my question is if adding the ethylen glycol would interfere with the concentration of starch?
Nope; as long as it is all on a weight basis, there is no density effect.Cyrus the great said:Is density of ethylen glycol effect the concentration of starch?
Yes, wt% is 3% "dry basis." My experience in the starch handling industries is that "dry basis" or "dry solids basis" is used to prevent any confusion.Cyrus the great said:So my question is now the concentration wt % of starch is 7.77/230=3.37 % or we should consider 7/230=3 %?