Answer:
(a) 49.0 mm
Explanation:
#First we need to calculate the height of the mercury arm:
Reduced pressure is 715.7torr, Initial Pressure is 797.3torr, Required pressure is:
[tex]P_g_a_s=P_a_t_m+P_h\\[/tex]
The difference in the two arms will give the pressure difference between the gas placed in the flask attached to an open-end mercury manometer.
[tex]P_g_a_s=P_a_t_m+P_h\\797.3=P_a_t_m+(136.4mm-103.8mm)\\P_a_t_m=764.7mm\\\\h_t_o_t_a_l=136.4mm+103.8mm=240.2mm\\\\P_g_a_s=P_a_t_m+\bigtriangleup h\\\bigtriangleup h=P_g_a_s-P_a_t_m\\\\\bigtriangleup h=715.7mm-764.7mm\\=-49mm[/tex]
Hence the height of the mercury in the arm is 49.00mm