PRC Chemist case studies
PRC Chemist · Put your knowledge to work in context.
The Chemist Licensure Examination is one of the licensure examinations administered by the Professional Regulation Commission (PRC) of the Republic of the Philippines. Passing it, together with registration, allows a candidate to use the title of Registered Chemist and to hold a Professional Identification Card; the PRC administers the application, examination scheduling, registration, and renewal processes through its official online portals. The PRC Chemist case studies are 5 cases and about 4,994 words.
1Limestone Neutralization of Spent Pickle Liquor: When pH Is Not Acidity
An electroplating plant must neutralize 20.0 m³ of spent pickle liquor before discharge. The permit allows pH 6.0–9.0 and no more than 0.5 mg/L Ni at the outfall.
952 words, about 5 min2HPLC Method Transfer to a Narrow-Bore Column: Reading a Plate-Count Collapse
A contract lab is transferring an isocratic reversed-phase assay for a small-molecule API to a narrow-bore column to cut solvent use. Original system: 150 × 4.6 mm, 5 µm C18, 1.0 mL/min, 50:50 (v/v) acetonitrile–20 mM phosphate buffer pH 6.8, 30 °C, 214 nm; main peak k′ = 2.8, N = 7,000, USP tailing 1.05, resolution 2.5 from the nearest specified degradant (specification ≥ 2.0).
967 words, about 5 min3Base-Mediated Methylenation of a β-Amino Ketone: When the Ylide Is the Wrong Reagent Class
A process group is scaling the methylenation of tert-butyl (3-oxobutyl)carbamate (1) to the corresponding terminal alkene, a building block for a protease inhibitor. The current route generates the ylide from methyltriphenylphosphonium bromide (1.5 equiv) and potassium tert-butoxide (1.6 equiv) in THF at 0 °C, adds 1, warms to 20 °C and holds for 16 h.
941 words, about 5 min4Temperature Coefficient of a Zn–Ag₂O Cell: Is the Cold Chamber Really Needed?
A development team is qualifying an alkaline Zn–Ag₂O button cell for an outdoor sensor that must start at −20 °C. A technician reports open-circuit voltages measured with a handheld 10 MΩ meter after 30 s stabilisation: 1.606 V at 0 °C, 1.592 V at 25 °C and 1.578 V at 45 °C.
1,072 words, about 5 min5Methanol Column Pushed Past Its Hydraulic Limit After a Steam Curtailment
After a site-wide steam curtailment, the board of a methanol–water column was pushed: reflux was cut from 1.4 to 1.1 (R = L/D) and feed was raised from 12.0 to 13.5 t/h at 40 wt% methanol. Within 6 h the top product fell from 99.6 to 96.8 wt% and the bottoms rose from 0.08 to 0.90 wt%.
1,062 words, about 5 min