Fundamentals of Material & Energy Balance Calculations — Winter 2020

Define following terms (a) Yield (b) limiting reactant and (c) Molality

What are the methods of expressing the composition of mixtures and solutions?

The waste acid from a nitrating process containing 20% HNO , 55%3 H SO and 25% H Oby weight is to be concentrated by addition of242 concentrated sulphuric acid containing 90% HNO to get desired mixed3 acid containing 26% HNO and 60% H SO . Calculate the quantities of324 waste and concentrated acids required for 1000 kg of desired mixed acid.

2000 kg of wet solids by weight are fed to a tray dryer where it is dried by hot air. The product finally obtained is found to contain 1 % moisture by weight, calculate:

The kg of water removed from solids,

The kg of product obtained.

Explain Recycle, Purge, bypass with suitable diagram and also define the overall and single pass fraction conversion.

Amixture of benzene vapour and nitrogen gas at 297 Kand 100 kPa has a relative humidity of 60%. It is desired to recover 80% of benzene by cooling a mixture to 283 Kand compressing to a suitable pressure. Find out the pressure required for above duty. Data: Vapour pressure of benzene at 297 K = 12.2 kPa

Write down the steps to be followed for the calculation of material balance problem.

Brief about raoult’s law and henry’s law for gas-liquid system.

Amixture of acetone vapour and nitrogen contains 14.8% acetone by volume. Calculate the following at 293 Kand a pressure of 99.33 kPa.

Partial pressure of acetone.

Moles of acetone per mole of nitrogen.

Relative saturation of mixture at 293 K.

Percentage saturation of mixture at 293 K. Data: Vapour pressure of acetone at 293 K = 24.638 kPa

Define NCV and GCV.

Atank holds 100 m3 of a water-salt solution in which 4 kg of salt is dissolved. Water runs into tank at the rate of 5 m3/min and salt solution overflows at the same rate. If the mixing in the tank is adequate to keep the concentration of salt in the tank uniform at all times, how much salt is in the tank at the end of 50 min. Assume that the density of the salt solution is essentially the same as that of water.

Anatural gas has the following composition on mole basis: CH = 84%,4 C H =13% and N = 3%242 Calculate the heat added to heat 10 kmol of natural gas from 298 Kto 523 Kusing heat capacity dat given below: Cp= a + bT+ cT2+dT3 kJ/(kmol.K) Gas a b×103 c×106 d×109 CH 19.2494 52.1135 11.973 -11.31734 C H 5.4129 178.0872 -67.3749 8.714726 N 29.5909 -5.141 13.1829 -4.9682

Define (a) Adiabatic saturation temperature (b) Wet bulb Temperature (c) Molal humidity

Give Classification of material balance problems with and without chemical reaction and explain it briefly.

The gaseous reaction A = 2B + Ctakes place isothermally in a constant pressure reactor. Starting with a mixture of 75 % Aand 25 % inerts (by volume), in a specified time the volume double. Calculate the conversion achieved.

Discuss Proximate and Ultimate analysis of coal.

Calculate the heat of reaction at 298.15 Kof the following reaction: 3CaSO + SiO 3 CaO.SiO + SO + 3/2 O 4(s) 2(s) 2(s) 2(g) 2(g) Component ΔH0, kJ/mol at 298.15 K f (250 C) CaSO -1432.7 4(s) SiO -903.5 2(s) 3 CaO.SiO -2879 2(s) SO -296.81 2(g) O 0.0 2(g)

1 kg nitrogen is mixed with 3.5 m3 of hydrogen at 300 Kand 101.3 kPa and sent to the ammonia converter. The product leaving the converter analyzed 13.7 % ammonia, 70.32 % hydrogen and 15.98 % nitrogen. i. Identity the limiting reactant. ii. What is the present excess of excess reactant? iii. What is the present conversion of the limiting reactant?

98 grams of sulphuric acid are dissolved in water to prepare one litre of solution. Find normality and molarity of solution.

Explain orsat analysis with diagram.

Acetone is recovered from an acetone-air mixture containing 25% (volume) acetone by scrubbing with water. Assuming that air is insoluble in water, determine the percent of acetone in the entering gas that is absorbed if the gas leaving the scrubber analyzes 5% acetone.2

Write in brief about selectivity.

Write down statement of Amagat’s law with mathematical expression.

Acontinuous distillation column is used to regenerate solvent for use in a solvent extraction unit. The column treats 200 kmol/hr of a feed containing 10 % mole ethyl alcohol and the rest is water. The overhead product is 89% mole alcohol and the bottom product is 0.3% mole alcohol. The overhead product is sent to the extraction unit and the bottom is wasted. What is the daily requirement of make-up alcohol in the solvent extraction unit?