# how n1t1/p1 =n2t2/p2is derived from the gas equation which is pv=nrt

We have PV = nRT, on rearranging - PV/ nT = R.

If 2 different conditions are given , then we have- $\frac{{P}_{1}{V}_{1}}{{n}_{1}{T}_{1}}=\frac{{P}_{2}{V}_{2}}{{n}_{2}{T}_{2}}$ ( as R is constant)

If V is constant for given condition then V1 = V2, therefore above equation becomes

$\frac{{P}_{1}}{{n}_{1}{T}_{1}}=\frac{{P}_{2}}{{n}_{2}{T}_{2}}or\phantom{\rule{0ex}{0ex}}\frac{{n}_{1}{T}_{1}}{{P}_{1}}=\frac{{n}_{2}{T}_{2}}{{P}_{2}}$

Regards

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