Question

Although gallium is a solid at STP, it had a low melting point (29.76 degrees Celsius) and a liquid density of 5.9 g/cm^3. If liquid gallium is used as the barometric liquir instead of mercury, how far would Ga(l) travel up the column when the barometer is exposed to 1 atm pressure?

Answer 1

In millimeters of mercury, pressure of 1atm is

P=1atm×(760 mmHg/1atm)=760 mmHg

Therefore, at 1 atm the mercury rise to 760 mm height.

We need to calculate how much the Ga(I) would rise when we use Galium in barometer instead of Mercury.

Pressure = d_Ga*g*h_Ga=d_Hg*g* h_Hg

The density of galium = d_Ga = 5.9 g/cm³

The density of mercury= d_Hg = 13.53 g/cm³

gravitational acceleration = g

Height of the mercury column = h_Hg = 760 mm

Height of the Galium column = h_Ga = ?

Plugging these values;

Height of the Galium column = h_Ga = (d_Hg*g* h_Hg)/d_Ga*g

                                                 = (13.53 g/cm³ x 760 mm) /5.9 g/cm³

                                                = 1742 mm = 1.742 m

Therefore, if we use Galium instead of mercury, the column height will rise to 1.742 meters height.