The flow rate required to yield a specified reading on an orifice meter varies inversely as the square root of the fluid density; that is, if a fluid with density p₁(gfcm³) flowing at a rate V (cm³/s) yields a meter reading then the flow rate of a fluid with density p required to yield the same reading is

V₂ = V₁ (p₁/p₂)^1/2

(a) Suppose an orifice meter calibrated with nitrogen at 25°C and 758 mm Hg is used to measure the flow rate of a process stream of hydrogen at 50°C and 1800 mm Hg. and the value read from the calibration chart is 350 cm³/s. Calculate the true volumetric flow rate of the gas.

(b) Repeat part (a), only suppose the process fluid contains 25 mole% CH₄ and the balance C₃H₈.