Material and Energy balances, 313a
Assignment #2
Due date: Sept.23, 2003
Sept. 16, 2003
1. Five thousand barrels of 28°API gas oil are blended with 20,000 bbl of 15°API fuel oil.
What is the density of the mixture in lb/gal and lb/ft3. Assume that the volumes are
additive. 1 bbl = 42 gal. The density of water at 60°F = 0.999 g/cm 3.
2. Two immiscible liquids (S.G.1
= 0.963, S.G.2 = 1.154) are allowed to separate in a
vessel. A block (dimensions, 9x9x9 in) that weights25.8 lb is dropped into the vessel.
Will the block float on the top, stop at the interface where the two liquids are separated
or sink? What fraction of the volume of the block is in one or both of the liquids.
3. One barrel each of gasoline (55 oAPI ), kerosene (40 oAPI ), gas oil (31 oAPI ) and
isopentane (96 oAPI ) are mixed what is the composition of the mixture in wt%. What is
the API and the density of the mixture ing/cm3 and lb/gal.
4. A gas mixture consists of three components with the following analysis
Gas
Molecular wt.
Mole fraction
Mass fraction
A
40
0.4
--
B
--
--
18.75
C
50
20
--
Calculate : a) molecular weight of component B
b) Average molecular weight
5. A liquid mixture of components A, B, and C containing 10 kg of A analyses 25% B and
contains 1.5 moles of C per mole of B. The respective molecular weights of A, B, and
C are 56, 58, and 72, and the specific gravities are 0.56, 0.60, and 0.67. Ignoring
volume change on mixing, Calculate:
a) the analysis of the mixture in mole %
b) the average molecular weight of the mixture
c) the volume percent A on a B free basis
d) density of the mixture
e) total number of moles of the mixture
6. Sulfuric acid can be manufactured by the contact process according to the following
reactions:
(1) S + 02 = SO,
(2) 2SO 2 + 0 2 = 2S03
(3) S03 + H2O = H2SO4
You are asked as part of the preliminary design of a sulfuric acid plant with a
design capacity of 2000 tons/day of
H 2SO4 (93.2% by weight) to calculate
the following:
(a) How many tons of pure sulfur are required per day to run this plant?
(b) How many tons of oxygen are required per day?
(c) How many tons of water are required per day for reaction (3)?
7. One can view the blast furnace from a simple viewpoint as a process in which
the principal reaction is:
Fe2O3 + 3C = 2Fe + 3CO
But some undesired side reactions occur, mainly
Fe2O3 + C = 2FeO + CO
After mixing 600 pounds of carbon with 1 ton of pure iron oxide (Fe2O3 ), the
process produces 1200 lb of pure iron, 183 lb of FeO and 85 lb of Fe2O3 . Calculate
the followings:
a) The percentage of excess carbon furnished in on the first reaction
b) The percentage conversion of Fe2O3 to Fe
c) The lb of carbon used up and the lb of CO produced per ton of Fe2O3
charged
8. Diborane, B2H6, a possible rocket propellant, can be made by using lithium hydride
based on the following reaction:
6LiH + 2BCl3 = B2H6 + LiCl
If you mix 200 lb of LiH with 1000 lb of BCl3 you recover 45 lb of B2H6. Determine:
a) the limiting reactant
b) the excess reactant
c) the percent excess reactant
d) the percent conversion of lithium hydride to diborane
e) the degree of completion of the reaction
f) the yield of diborane based on LiH charged
g) the lb of LiCl produced.