(1)左管内气体压强:p1=p0+h2=80cmHg,
右管内气体压强:p2=p左+h1=85cmHg,
p2=p0+h3,解得,右管内外液面高度差h3=10cm,
右管内气柱长度L2=L1-h1-h2+h3=50cm;
(2)设玻璃管截面积S,由理想气体状态方程,
=
p1L1S T1
,[P0+ρg(h2+L3?L1)]L3S T2
=80×50 300
,解得:L3=60cm.(75+5+L3?50)L3
T2
答:(1)右管内气柱的长度为50cm.
(2)关闭阀门A,当温度升至405K时,左侧竖直管内气柱的长度为60cm.