Why do we use a column of mercury rather than a column of water to measure pressure?

1 Answer
Mar 23, 2016

Answer:

Consider the density of mercury versus that of water.

Explanation:

#rho_(Hg) = 13.55*g*mL^-1; rho_("water") = 1.00*g*mL^-1; #

One atmosphere will support a column of mercury #760# #mm# high. It would support a column of water approx. #10# #m# high. Sometimes, columns of water are used to measure osmotic pressures, which are much smaller than atmospheric pressures.