Question

If the density of a certain gas at 30.c and 768 torr is 1.35kg/m3 its density at STPwould be
(1) 1.48kg/m3
(2) 1.58kg/m3
​(3) 1.25kg/m3
(4) 1.4kg/m3

Answer 1

Option (1) is correct

At STP, the pressure and temperature can be shown as

$P_2 = 760 torr</p> <p>\\ T_2 = 273 K$

Given,

The given pressure and temperature can be shown as

$P_1 = 768 torr</p> <p>\\ T_1 = 30 C^0 = 303 K$

The density at STP can be determined as:

$d_S_T_P = d x (P_1 / P_2) x (T_1 / T_2) </p> <p>\\ = 1.35 kg /m^3 x (768 torr / 760 torr) x (303K / 273K) </p> <p>\\ = 1.49 kg /m^3$

Thus, density at STP is 1.49 kg /m^3