Chemical Engineering
2022 · Paper 1
Take it one question at a time. Try an answer, then check your understanding.
Complete GATE CH 2022 Paper 1 overview, original pages and practice · Timed previous-paper practice
Questions 55–57 of 65. Imported answers require review unless explicitly marked reviewed.
Question 55
Open questionCHNAT2 marksNeeds review
A single-effect evaporator with a heat transfer area of 70 m
concentrates a salt solution using steam. The salt solution feed rate and temperature are 1000 kg h
and 40 °C, respectively. The saturated steam feed rate and temperature are 750 kg h
and 150 °C, respectively. The boiling temperature of the solution in the evaporator is 80 °C. The average specific heat of the solution is 0.8 kcal kg
K
. The latent heat of vaporization is 500 kcal kg
. If the steam-economy is 0.8, the overall heat transfer coefficient is ______ kcal h
m
K
(rounded off to the nearest integer).Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 56
Open questionCHNAT2 marksNeeds review
An equimolar binary mixture is to be separated in a simple tray-distillation column. The feed rate is 50 kmol min
. The mole fractions of the more volatile component in the top and bottom products are 0.90 and 0.01, respectively. The feed as well as the reflux stream are saturated liquids. On application of the McCabe-Thiele method, the operating line for the stripping section is obtained as
where
and
are the mole fractions of the more volatile component in the vapor and liquid phases, respectively. The reflux ratio is ______ (rounded off to two decimal places).Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 57
Open questionCHNAT2 marksNeeds review
The dry-bulb temperature of air in a room is 30 °C. The Antoine equation for water is given as
where
is the temperature in K and
is the saturation vapor pressure in bar. The latent heat of vaporization of water is 2000 kJ kg
, the humid heat is 1.0 kJ kg
K
, and the molecular weights of air and water are 28 kg kmol
and 18 kg kmol
, respectively. If the absolute humidity of air is
kg moisture per kg dry air, then for a wet-bulb depression of 9 °C,
________________ (rounded off to one decimal place).Log in to check the answer
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