Most preparations for nitrocellulose from $\ce{(KNO3 + H2SO4)}$ mixture require the use of an ice bath during the process of dissolving $\ce{KNO3}$ into $\ce{H2SO4}$. Last time I did this I omitted this step and the nitrocellulose turned out to be of very low quality, but there's a number of other possible causes I can think of. Therefore, for the sake of troubleshooting I have this question: What is the purpose of an ice bath during this step? Is it to just limit the fuming, or does omitting it lead to decomposition of $\ce{HNO3}$ significant enough to impact the yield? I did not see any brown $\ce{NO2}$ fumes coming out, just the typical white mist of acid.

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    $\begingroup$ What generally can happen if you run an (exothermic) reaction at a higher starting temperature? $\endgroup$ – Karl Jan 3 '20 at 11:11
  • $\begingroup$ It is an exothermic reaction and generates a lot of heat. $\endgroup$ – Nilay Ghosh Jan 3 '20 at 11:32
  • $\begingroup$ It's not very exothermic, I imagine I'd have to dump all KNO3 at once to see it runaway. So it's just an additional safety measure? $\endgroup$ – Francis L. Jan 3 '20 at 11:51
  • $\begingroup$ Its certainly also a safety measure. You are aware that there are three different basic types of nitrocellulose (mono, di, trinitrate) ? $\endgroup$ – Karl Jan 3 '20 at 14:45

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