Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Winter 4th Sem New 2140406 Stoichiometry Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? IV (New) EXAMINATION ? WINTER 2019
Subject Code: 2140406 Date: 12/12/2019
Subject Name: Stoichiometry
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Define: Ideal gas law, Raoult?s law, Henry?s law. 03
(b) The conductance of a fluid ?flow sytem is defined as volumetric flow rate, reffered
to a pressure of one torr (133.322 Pa.). For an orifice, the conductance C can be
computed from
3
89.2 /
T
C A ft s
M
?
Where A = area of opening.ft
2
, T = Temperature,
0
R, M = Molecular Weight.
Convert the empirical equation into SI units.
04
(c) The average molar mass of a flue gas sample is calculated by two different
engineers. One engineer uses the correct molar mass of 28 for N2 and determines
the average molar mass to be 30.08, the other engineer using an incorrect value of
14, calculate the average molar mass to be 18.74. Calculate i) the volume % of N2
in the flue gases , and ii) if the remaining components of the flue gases are CO2
and O2.
07
Q.2 (a) Iron metal weighs 200 lb & occupies a volume of 117 lit. Find the density in
gm/cm
3
.
03
(b) The diameter and height of a vertical cylindrical tank are 5 ft and 6 ft 6 inch
respectively. It is full up to 75% height with carbon tetrachloride (CCl 4), the
density of which is 1.6 kg/lit. Find the mass in kg.
04
(c) Cracked gas from a petroleum refinery has the following composition by vol.;
Methane 45%, Ehtane 10%, Ehtylene 25%, Propane 7%, Propylene 8%, n-Butane
5%. Find: a) Average molecular weight of the mixture, and b) the composition by
wt%.
07
OR
(c) An aqueous solution of K2CO3 is prepared by dissolving 43 kg K2CO3 in 100 kg
water at 293 K. Find the molarity, normality and molality of the solution. Take
specific gravity of the solution as 1.3 .
07
Q.3 (a) Discuss methods of solving material balance problems without chemical reaction. 03
(b) State recycling and bypassing operations with their importance in the process
industries.
04
(c) The waste acid from a nitrating process containing 20% HNO3, 55% H2SO4 and
25% H2O by weight is to be concentrated by addition of concentrated sulphuric
acid containing 95% H2SO4 and concentrated nitric acid containing 90% HNO3 to
get desired mixed acid containing 26 % HNO3 and 60% H2SO4. Calculate the
quantities of waste acid and concentrated acids required for 1000 kg of desired
acid.
07
OR
Q.3 (a) Define : Conversion, yield, selectivity. 03
(b) Formaldehyde is produced from methanol catalytic reactor. The production rate of
formaldehyde is 1000 kg/h. If conversion of methanol is 65%, calculate the
required feed rate of methanol.
04
FirstRanker.com - FirstRanker's Choice
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? IV (New) EXAMINATION ? WINTER 2019
Subject Code: 2140406 Date: 12/12/2019
Subject Name: Stoichiometry
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Define: Ideal gas law, Raoult?s law, Henry?s law. 03
(b) The conductance of a fluid ?flow sytem is defined as volumetric flow rate, reffered
to a pressure of one torr (133.322 Pa.). For an orifice, the conductance C can be
computed from
3
89.2 /
T
C A ft s
M
?
Where A = area of opening.ft
2
, T = Temperature,
0
R, M = Molecular Weight.
Convert the empirical equation into SI units.
04
(c) The average molar mass of a flue gas sample is calculated by two different
engineers. One engineer uses the correct molar mass of 28 for N2 and determines
the average molar mass to be 30.08, the other engineer using an incorrect value of
14, calculate the average molar mass to be 18.74. Calculate i) the volume % of N2
in the flue gases , and ii) if the remaining components of the flue gases are CO2
and O2.
07
Q.2 (a) Iron metal weighs 200 lb & occupies a volume of 117 lit. Find the density in
gm/cm
3
.
03
(b) The diameter and height of a vertical cylindrical tank are 5 ft and 6 ft 6 inch
respectively. It is full up to 75% height with carbon tetrachloride (CCl 4), the
density of which is 1.6 kg/lit. Find the mass in kg.
04
(c) Cracked gas from a petroleum refinery has the following composition by vol.;
Methane 45%, Ehtane 10%, Ehtylene 25%, Propane 7%, Propylene 8%, n-Butane
5%. Find: a) Average molecular weight of the mixture, and b) the composition by
wt%.
07
OR
(c) An aqueous solution of K2CO3 is prepared by dissolving 43 kg K2CO3 in 100 kg
water at 293 K. Find the molarity, normality and molality of the solution. Take
specific gravity of the solution as 1.3 .
07
Q.3 (a) Discuss methods of solving material balance problems without chemical reaction. 03
(b) State recycling and bypassing operations with their importance in the process
industries.
04
(c) The waste acid from a nitrating process containing 20% HNO3, 55% H2SO4 and
25% H2O by weight is to be concentrated by addition of concentrated sulphuric
acid containing 95% H2SO4 and concentrated nitric acid containing 90% HNO3 to
get desired mixed acid containing 26 % HNO3 and 60% H2SO4. Calculate the
quantities of waste acid and concentrated acids required for 1000 kg of desired
acid.
07
OR
Q.3 (a) Define : Conversion, yield, selectivity. 03
(b) Formaldehyde is produced from methanol catalytic reactor. The production rate of
formaldehyde is 1000 kg/h. If conversion of methanol is 65%, calculate the
required feed rate of methanol.
04
2
(c) An effluent sample from a formaldehyde plant is found to contain methanol and
formaldehyde. The analysis of the solution indicated that TOC and ThOD are 258.3
mg/lit and and 965.5 mg/lit respectively. Find the concentration of each of the
compounds in the sample.
07
Q.4 (a) Define: i) Standard Heat of Formation ii) Standard Heat of Combustion iii)
Standard Heat of Reaction.
03
(b) Soyabeen seeds are extracted with n-hexane in batch extractors. The flaked seeds
contain 18.6% oil, 69.0% solids and 12.4% moisture. At the end of the extraction
process, de-oiled cake (DOC) analysis yields 0.8% oil, 87.7% solids and 11.5%
moisture. Find the percentage recovery of oil. All percentages are by mass.
04
(c) In the Deacon process for manufacturing chlorine, HCl gas is oxidized with air.
The reaction taking place is: 4HCl(g) + O2(g) ? 2H2O(g) + 2Cl2(g)
If the air is used in excess of 30% of that theoretically required, and if the oxidation
is 80% complete, calculate the composition by volume of dry gases leaving the
reaction chamber.
07
OR
Q.4 (a) State Hess?s law of constant heat summation with example. 03
(b) Pure methane is heated from 303K to 523K at atmospheric pressure. Calculate the
heat added per kmol methane, using data given. ?? ??
= ?? + ???? + ?? ?? 2
where Cp
o
= Ideal gas heat capacity at 101.325 kPa, kJ/(kmol.K)
and T = Absolute temperature, K
Compound a b x 10
-3
c x 10
-6
d x 10
-9
Methane (CH4) 19.2494 52.1135 11.973 -11.3173
04
(c) A pilot plant reactor was charged with 50 kg naphthalene and 200 kg (98% by wt.)
H2SO4. The reaction was carried out for 3 hours at 433 K. the reaction goes to near
completion. The product distribution was found to be 18.6% monosulphonate
naphthalene and 81.4% disulphonate naphthalene. Calculate: a) the quantities of
monosulphonate (MSN) and disulphonate (DSN) products, and b) the complete
analysis of product.
07
Q.5 (a) Explain material balance of Extractor. 03
(b) A heat exchanger for cooling a hot hydrocarbon liquid uses 10000 kg/hr of cooling
water, which enters the exchanger at 294K. the hot oil at the rate of 5000 kg/hr
enters at 423K and leaves at 338K and has an average heat capacity of 2.51
KJ/(kg.K). Calculate the outlet temperature of water.
04
(c) Obtain an empirical equation for calculating the heat of reaction at any temperature
T (in K) for the reaction CH4(g) + C2H4(g)
?
C3H8(g). Data: ??? ?? ?
at 298 K = -
82.66 kJ/mol , ?? ??
= ?? + ???? + ?? ?? 2
+ ?? ?? 3
, J/kmol.K
Component a b ? 10
3
c ? 10
6
d ? 10
9
CH4 (g) 19.2494 52.1135 11.973 -11.3173
C2H4(g) 4.1261 155.0213 -81.5455 16.9755
C3H8(g) -4.2227 306.264 -158.6316 32.1455
07
OR
Q.5 (a) Explain material balance of Crystallizer. 03
(b) Define & explain following terms: i) absolute humidity (H) ii) % humidity iii)
wet-bulb temp (WB) iv) humid heat (Cs).
04
(c) 10000 kg of an aq sol containing 29.6% by wt anhydrous Na2SO4 at 413 K is
charged to the crystallizer. During the cooling, 5% of initial water is lost by
evaporation. As a result, crystals of Na2SO4H2O crystallize out. If the mother
liquor is found to contain 18.3 % (by wt) anhydrous Na2SO4. Cal the yield & the
quantity of mother liquor.
07
*************
FirstRanker.com - FirstRanker's Choice
This post was last modified on 20 February 2020