An iron cylinder contains helium at a pressure of 250 k Pa at 300 K. The cylinder can withstand a pressure of 1 xx 10^6Pa. The room in which cylinder is placed catches fire. Predictthe temperature (in K) at which the cylinder will blow up before it melts or not (m.p.t. of the cylinder =1800K)..

An iron cylinder contains helium at a pressure of 250 k Pa at 300 K. T

1.	An iron cylinder contains helium at a pressure of 250 k Pa at 300 K. The cylinder can withstand a pressure of 1 xx 10^6Pa. The room in which cylinder is placed catches fire. Predictthe temperature (in K) at which the cylinder will blow up before it melts or not (m.p.t. of the cylinder =1800K)..
Answer» Solution :According to the gas equation `(P_1V_1)/T_1 = (P_2V_2)/T_2` In the present CASE, `P_1 = 250 k Pa=50 xx 10^3 Pa, T_1 = 300 K` `P_2 = 1 xx 10^6 Pa, T_2` = ? and `V_1 = V_2` (since the cylinder is closed) `:. "" P_1/T_1=P_2/T_2` or`(250 xx 10^3)/300= (1xx10^6)/T_2 or T_2 = 1200K` Thus, the maximum pressure which the cylinder can withstand will be attained at 1200 K which is much less HAN the melting point of IRON `(1530^@C)`. Therefore, the cylinder will burst before melting.