Question $4$

A pipeline conveys benzene from one point to the other. A gauge attached to line reads $150$ kPa. It is desired to check the gauge reading with benzene $-$over$-$mercury U$-$tube manometer. Determine the expected height difference of the mercury in the manometer; if on one end the manometer is open to the atmosphere and on the other end where the gauge pressure is connected there is a $3cm$ height of benzene above the mercury meniscus. $($benzene density is $876k\frac{g}{m^3}$ and mercury $13600k\frac{g}{m^3})$

Question $5$

The temperature of the earth's atmosphere drops about $5C$ for every $1km$ above the earth. If the temperature of the air on the ground is $15C$ and the pressure is $760mmHg.$ At what height above the earth is the pressure $380mmHg?$ Assume the air behaves as an ideal gas.

Use the following Hydrostatic equilibrium equation:

$dp+gdz=0$

Question $6$

A cylindrical tank is vented to the atmosphere that serves as a reservoir for octane before it is piped to another location is $140ft$ in diameter. Determine the pressure difference between the top and bottom of the walls due to the octane when the tank is filled to a depth of $30ft(9\mathrm{.}14m).$ Why is the vent necessary?

NB: Atmospheric conditions are such that the pressure is $1$atm and temperature $25C.$ SG of octane is $0\mathrm{.}701$

Question $7$

A continuous gravity decanter separates chlorobenzene from an aqueous wash liquid. If the total depth of the separator is $1m$ and the interphase is to be $0\mathrm{.}6m$ from the vessel floor, what should the height of the heavy$-$liquid overflow leg be$?$

If the separator is to separate $1600k\frac{g}{h}r$ chlorobenzene from $2100k\frac{g}{h}r$ wash liquid, what volume of the separator is needed?

The following information is provided

The density of chlorobenzene is $1109k\frac{g}{m^3}$ and that of the wash liquid $1020k\frac{g}{m^3}$

The wash liquid is the continuous phase

The viscosity of the wash liquid is $0\mathrm{.}72cP$

The following equations are provided: