DAY 1 QUIZ Flashcards
Determine the concentration of carbon monoxide at double the pressure after adding 0.20 mole of CO if one mole of CO and water vapor is initially placed in a container with volume of 20 liters at 9000C. Assume CO2 and H2 are the final products. The equilibrium concentration of the carbon monoxide is 2.24 x 10 -3 M. (Oct 2021 PBE)
A. 4.9 x 10^-3 M
B. 15 x 10^-3 M
C. 2.7 x 10^-3 M
D. 11.3 x 10^-3 M
A. 4.9 x 10^-3 M
An MRT line run across the Pasig River which has an average flow rate of 54 cubic meters per second. The MRT maintenance company sprays the track easement bridge crossing the river with an herbicide concentration in the river of 66 μg/liter. Pasig City is 18.5 km downstream. The flow velocity of the river is 1.25 meters/sec. If the herbicide degrades at a constant rate of 0.65 μg/day, determine the concentration of the herbicide in the river near Pasig City. (Oct 2021 PBE)
A. 67.2 μg/liter
B. 58.4 μg/liter
C. 46.6 μg/liter
D. 83.1 μg/liter
B. 58.4 μg/liter
What is the theory in two or three dimensional collision to be applied when playing billiards and in order to sink the target ball in the corner pocket? (Oct 2021 PBE)
A. The center of the mass theory where the center of the mass of the system moves as all the mass in the system were concentrated at that point and one of them is initially at rest, and they were in perpendicular direction of the collision.
B. Proton – proton elastic collision.
C. The components of momentum in an isolated system in each of the directions (x, y, z) are conserved independently.
D. Where two equal masses undergo a glancing elastic collision.
D. Where two equal masses undergo a glancing elastic collision.
Determine whether a closed cylinder piston will rise, fall or remain in the same position, if a mixture of one gram butane gas and oxygen were ignited with no heat escaping to the surrounding. C4H10 (g) + O2 (g) → CO2 (g) + H2O (l). (Oct 2021 PBE)
A. rise
B. the same
C. fall
D. the cylinder will expand and break
C. fall
Why does the use of sunglasses with adjustable shading a practical illustration of the Le Chatelier’s principle? (Silver chloride is the compound used in the glasses, which upon exposure to sunlight produces silver Ag and chlorine Cl2). (Oct 2021 PBE)
A. Any of these
B. The addition of energy in the form of sunlight drives the equilibrium to the right and its removal drives the equilibrium to the left, since the more metal is produced, the darker the glasses.
C. When external stress is applied to a system in equilibrium, which in this case refers to the production of silver metal which causes a change in the shade of the sunglasses.
D. The changes in temperature cause the exothermic or endothermic reaction of the silver metal production to shift from left to right or vice-versa, thus causing the shades to change.
B. The addition of energy in the form of sunlight drives the equilibrium to the right and its removal drives the equilibrium to the left, since the more metal is produced, the darker the glasses.
In electrochemistry, specific conductance is defined as (1000/N)x K, where N is the normality of the salt solution and K is the specific conductance, current is carried by oth anions and cation to a different degree. Thus the equivalence of a salt is the sum of the ionic conductances of the cation and anion. If the ionic conductance of Na+ is 50.1 and that chloride is 76.3 what is the estimated concentration of NaCl in mg/L? The specific conductance of NaCl is 125 x 106. (Oct 2021 PBE)
A. 49
B. 58
C. 29
D. 38
B. 58
Choose the process/es that occur/s with a decrease in entropy. (Oct 2023 PBE)
A. Dissolving salt in water
B. Boiling
C. Sublimation of dry ice
D. Freezing of water
D. Freezing of water
When a can of soda is opened and CO2 is released to the atmosphere, what is the resultant pH of the soda? (Oct 2021 PBE)
A. decreases
B. increases
C. the same
D. all of these
B. increases
A chemical plant chemist working in the Pasig River Area was given the task to determine which of the two acid solutions can be discharged to the Pasig River with minimal effect on the river water. The chemist analyzed 0.1M solutions of the acetic acid (HAc) with Ka of 1.81 x 10-5 and hydrofluoric acid (HF) with Ka of 6.6 x 10-4. Which acid solution can be discharged? (Oct 2021 PBE)
A. HF
B. HAc
C. combination of both
D. not applicable
B. HAc
If there are two closed systems with fixed volumes and in thermal contact, the changes in the properties of both systems may reach a certain state. If three systems are involved, then all systems are in equal state. (Nov 2019 PBE)
A. True
B. None of these
C. False
D. Not entirely true or false
A. True
How many moles of beryllium would a 43.1 pounds pure aquamarine contain? (Nov 2019 PBE)
A. 3.2x10^3 moles
B. 4.53 moles
C. 1.1x10^2 moles
D. 5.38x10^3 moles
C. 1.1x10^2 moles
When a small sample of 27 mL of 0.311 M of NaOH is titrated with 0.741 M of sulfuric acid, determine how many milliliters of the sulfuric acid solution are required to reach the end point. (Oct 2021 PBE)
A. 6.22
B. 3.77
C. 5.67
D. 7.41
C. 5.67
Two samples of vitamins were synthesized in the UST chemical laboratory from citrus fruit and sodium acerbate. Estimate the mass of oxygen in grams in Sample 2, if sample 1 contains 1.6 grams of carbon and 2 grams of oxygen, while sample 2 contains 6.4 grams of carbon. (Nov 2019 PBE)
A. 8.42 g
B. 3.5 g
C. 1.78 g
D. 1.6 g
A. 8.42 g
When traveling at NLEX at 80mph, a stopped car in front causes you to suddenly skid to stop. What happened to the kinetic energy of the moving car? (Nov 2019 PBE)
A. It was transferred to the internal energy of the road
B. Some of it were converted to internal energy and some transferred to the road and surroundings
C. All of it transferred to the road and surroundings
D. All of it are still in the car
B. Some of it were converted to internal energy and some transferred to the road and surroundings
In a solution supersaturated with CO3-2 and Ca2, what is the final concentration of Ca+2 per liter of solution at equilibrium Ksp CaCO3 (s) = 8.30 (use the quadratic formula)? (Oct 2021 PBE)
A. 16.7 mg/L
B. 14.4 mg/L
C. 15.6 mg/L
D. 17.0 mg/L
A. 16.7 mg/L
