Day 1 Others Memorize

Question 1

(Nov. 2019 PBE) The distance of the Earth to
the most remote normal galaxy is calculated
to be:

Answer 1

2x1022m

Question 2

A certain volume of a
solution of KMnO4 will oxidize sufficient
potassium tetraoxalate that requires half of
that volume using 0.201N of KOH solution
for neutralization. Determine the quantity
of KMnO4 in a liter of its solution.

Answer 2

b. 2.01g
key: potassium tetraoxalate

Question 3

A newly graduate chemical engineer was assigned to team of
engineers in food processing plant.

Answer 3

B-B

Question 4

Determine the BEST combination of plant and location to BEST
conserve the environment, given the following data:

Answer 4

a. Plant (B) in Marikina River
Key: High DO, low D

Question 5

How many trucks would be needed to collect the waste twice weekly? The trucks each have a capacity of 4.5 MT and operate 5 days per week. Assume that the trucks average two loads per day at 75% capacity.

Answer 5

Germany – 4, US – 8

Question 6

A Chemical Engineer decided to make a twist with the old Filipino song “Ako ay may Lobo”. If the child had a 500 mL balloon (5/6 of its Maximum Stretching Capacity) filled with H2 gas, at what height will the child no longer see the balloon since it has burst? Assume that the pressure decreases 1 mm for every 100 cm rise in height.

Answer 6

127 m

Question 7

Determine the volume of carbon dioxide in cubic feet occupied by 120 lbs at a pressure of 1.5 atm.

Answer 7

750
Temp: 105 F

Question 8

Determine the number of days it will take for one milligram of rubidium to decay to 0.6 mg.

Answer 8

63
half life used: 86.2 days (Rb-83)

Question 9

Glutamic acid is used as one of the reagents for a standard to check the BOD test. Determine the theoretical oxygen of 150 ppm of glutamic acid.

Answer 9

212 ppm

Question 10

The design flow and overflow rates for a settling tank are 0.044 m3 · s−1 and 20 m · day−1, respectively. Determine the surface area of this tank. Determine the length of the tank, using conventional wisdom for length- to-width ratios. Determine the tank depth, assuming a detention time of 2 hours.

Answer 10

190 m2, 16 m and 1.7 m
W=L/5

Question 11

A power plant in a college town is burning coal on a cold, clear winter morning at 8:00 A.M. with a wind speed of 2.6 m · s−1 measured at 30 m elevation and an inversion layer with its base at a height of 697 m. The effective stack height is 30 m. Calculate the distance downwind XL at which the plume released will reach the inversion layer and begin to mix downward.

Answer 11

5.8 km

Question 12

A town of 20,000 in Laguna generates 0.96 kg/(capita)-day of MSW. A town of the same size in the Makati City in Metro Manila generates 1.9 kg/(capita)-day of MSW.
How much MSW is generated in each town?
How many trucks would be needed to collect the waste twice weekly? The trucks each have a capacity of 4.5 MT and operate 5 days per week. Assume that the trucks average two loads per day at 75% capacity. Calculate the number and volume of MSW in tons that enter the landfill

Answer 12

19100 kg/d and 39000 kg/d, 4 and 8 trucks, 58 m3/d 105 m3/d

Question 13

The Nairyosangha landfill located in Peshdadians serves a population of 562,400 people generating MSW at a rate of 1.89 kg · capita−1 · day. The volume of the landfill is 11,240,000 m3. At the present time, 63% of the landfill is used. The ratio of cover to compacted fill is 1.9. Determine projected life remaining for the landfill. Assume the density of the compacted waste to be 490 kg · m−3.

Answer 13

2.76 years

Start with volume then dimensional analysis

Question 14

A landfill with a gas collection system is in operation and serves a population of 200,000. MSW is generated at a rate of 1.95 kg · (capita)−1 · day−1. Gas is produced at an annual rate of 6.2 L · kg−1 of MSW delivered to the landfill. The gas contains 55% methane. Gas recovery is 15% of that generated. The heat content of the landfill gas is approximately 17,000 kJ · m−3 (a value lower than the theoretical value because of dilution of the methane with air during recovery). The landfill company and a developer have proposed to build a subdivision in the vicinity of the landfill and pipe the methane generated to the homes to be used for heating. The homes are estimated to use an average of 110 × 106 kJ of heat energy each year. Peak usage during winter is 1.5 times the average usage. How many homes can be built in the subdivision?

Answer 14

7 homes

Question 15

A solution of HOCl is prepared in water by adding 15 mg HOCl to a volumetric flask, and adding water to the 1-L mark. The final pH is measured to be 7.0. What are the concentrations of HOCl and OCl? What percent of the HOCl is dissociated? Assume the temperature is 250C.

Answer 15

[OCl-] = 6.39x10-5 M, [HOCl] =
2.22x10-4 M, 22.4%

Question 16

If the normality of HCl is greater by 10% compared to KOH, estimate the normality of the HCl solution when 0.67g of (NH4)2SO4 is dissolved in water, treated with excess NaOH and the ammonia released is passed through a solution of 20mL of HCl. The excess acid solution is titrated using 15.01mL of KOH solution.

Answer 16

0.152 N

Question 17

A solution is initially supersaturated with CO2− and Ca2+ such that the concentrations are both 3
50.0 mg · L−1. When equilibrium is ultimately reached what will be the final concentration of Ca2+?

Answer 17

16.7 mg · L−1

Question 18

U-238 half life

Answer 18

4.52x10^9 years

Question 19

A rock contains 0.688 mg 206Pb for every 1.000 mg
238U
present. Assuming that no lead was originally present, that all the 206Pb formed over the years has remained in the rock, and that the number of nuclides in intermediate stages of decay between 238U and 206Pb is negligible, calculate the age of the rock.

Answer 19

3.8×10^9 years

Question 20

A sewage lagoon that has a surface area of 10 ha and a depth
of 1 m is receiving 8640 m^3 d^- of sewage containing 100 mg
T^_ of biodegradable contaminant. At steady state, the effluent from the lagoon must not exceed 20mg• L^ - of biodegradable contaminant. Assuming the lagoon is well mixed and that there are no losses or gains of water in the lagoon other than the sewage input, what biodegradation reaction rate coefficient (d^-) must be achieved for a first-order reaction?

Answer 20

0.35

Question 21

An air jet operates at 2,500 rev/min and uses 7.89 × 10^3J of energy and exhausts 4.58 × 10^3 J for each crankshaft revolution.
Determine the quantity of gasoline fuel
consumed in one hour of operation if the heat of combustion is 4.03 × 10^7 J/liter.

Answer 21

29.4 L/h

Question 22

Suppose that we have a stain on an oil painting that we want to remove without damaging the painting. The stain is not water-insoluble. Knowing the polarities of the following solvents, which one would we try first: benzene, isopropyl alcohol, hexane

Answer 22

isopropyl alcohol

Question 23

There are approximately 20 amino acids in human protein.
Name 3 essential amino acids:
A
). Proline, glutamine, asparagine
B. Arginine, lysine, phenylalanine
C. Aspartic acid, glutamic acid, serine
D. Glycine, arginine, glutamic acid

Answer 23

B. Arginine, lysine, phenylalanine

Question 24

How do two free radicals react when they encounter each other?

Answer 24

They unite with covalent bond formation

Question 25

Determine the stability of the atmosphere given the following data collected for Tagaytay:
A. -1.02 degrees C per 100 meters
B. -3.01 degrees C per 100 meters
C. -2.11 degrees C per 100 meters
D. -2.92 degrees C per 100 meters

Answer 25

A. -1.02 degrees C per 100 meters

Question 26

Which among the following is the most abundant isotope of hydrogen?
(
Al Deuterium
B. Elerium
C.Protium
D. Tritium

Answer 26

Protium

Question 27

If the initial density of bacteria is 10^4 cells per liter at the end of the accelerated growth phase, what is the number of bacteria after 25 generations?

Answer 27

3.4x10^11 cell L^-

P = Po(2)^n

Question 28

Determine the half-life of the decay process for a sample of
Curium-243 when analysis showed that the activity of the sample decreased to 2923 disintegrations per second from the original 3011 dps.

Answer 28

K = 0.2x10^-1 yr^-1; t1/2 = 28.6 yr

Question 29

An industrial pollutant to a river flowing with a velocity of 0.5 m/s. At this point in the river, the concentration of the pollutant is 50 ppm. The pollutant follows first order degradation with a rate constant equal to 0.35 hr^-1. What will be the concentration of the pollutant in the river when If reaches a city 12 km from the industrial plant?

Answer 29

85

Question 30

2-4-6 chickenwire

Answer 30

First order

Question 31

Neohetramine, C16H21ON4 (285.37g/mol), is
a
common
antihistamine. A 0.1247-g sample containing this compound was analyzed by the Kjeldahl method. The ammonia produced was collected in H3BO3; the resulting H2BO3- was titrated with 26.13 ml of 0.01477 M HCI. Calculate the percentage of neohetramine in the sample.

Answer 31

22.08%

Question 32

angelic acid?

Answer 32

2-Methylbut-2-enoic acid

Question 33

A magician rotates a pail of water in a vertical circle with a radius of 0.50 meter amazes the audience because no water spilled out. What is the minimum speed at which no water will spill out?

Answer 33

3.13 m/sec/2

Question 34

What is the distance of the earth to most remote quasar, v
distance of the earth to most remote known galaxies and mean orbit radius of the earth about the sun?

Answer 34

6.4210^26, 9×10^25 and 1.5x10^11

Question 35

A flowing stream has an oxygen deficiency of 6 mg/L. However,
miles downstream the deficiency was reduced to 4 mg/L through atmospheric absorption. If the stream has a velocity of 2 mph and contains no BOD and other stream conditions are uniform through its length, estimate the oxygen deficit some 35 miles downstream from the original point.

Answer 35

1.46 mg/L

L1 = 10 mi

Question 36

Of the following pairs of physical systems, determine the one with the greater chemical potential.
a) (IA); one mole of H20 (1) at 100.1 deg; or (B); one mole of H20 (g) at 102 degC.
b) (2A); ten grams of Fe at 2 degC or (2B) ten grams of Fe at 36 degC.
c) (A); 25 liters of air at 1 atm pressure or (3B) the same amount of air compressed isothermally to 100 atm.

Answer 36

18, 2B, 3B