Johnson To

Projects

Lab work, builds, and analysis from school and on my own time.

The finished smart waste sorter: a wood and polycarbonate enclosure with two openings

Smart Waste Sorting System

Team project (14 members), January to May 2026

Up to 95% confidence classifying trash vs. recycling

  • Machined wood and polycarbonate parts for a 15″ × 30″ × 20″ hinged enclosure and helped assemble the final unit.
  • Tested dilutions of an alcohol-based disinfectant to balance cost and cleaning effectiveness.
  • The team trained a ResNet50 classifier on 10,000+ images and runs it on a Raspberry Pi; the sorter is in daily use.
View project site
Electrolysis setup: a DC power supply reading 4.0 V wired to graphite electrodes in a beaker of electrolyte, with collection tubes over each electrode

Hydrogen Electrolysis Optimization

Personal project, January to May 2026

Up to 88% Faradaic efficiency across 18 timed trials

  • Built an electrolysis cell with graphite electrodes and a sodium bicarbonate electrolyte after early pure-water runs produced little gas.
  • Ran 18 timed trials from 4.0 to 6.5 V, measuring current and H2 volume by water displacement.
  • Compared measured H2 output with Faraday’s law in Python (pandas, matplotlib) and linked an efficiency drop above 5.5 V to gas escaping the collection column.
View project site
Titration curve of ibuprofen with sodium hydroxide Modeled pH versus volume of 0.100 M NaOH added to 200 mg of ibuprofen. The pH starts near 3, rises slowly through a buffer region, equals the pKa of about 4.9 at the half-equivalence point near 4.8 mL, then jumps sharply at the equivalence point near 9.7 mL, where the pH is about 8.7. Ibuprofen + 0.100 M NaOH (modeled curve) 246810120481216 NaOH added (mL) pH pH = pKa ≈ 4.9 Equivalence point, 9.7 mL

Ibuprofen Concentration and Degradation Analysis

Chemistry lab project (team of 4), January to May 2026

Measured 19.6% heat degradation; tablets held 171 ± 17 mg vs. 200 mg labeled

  • Found ibuprofen concentration in tablets by acid-base titration with NaOH (1:1 neutralization).
  • Built a 4-point calibration curve in Python with matplotlib relating NaOH volume to concentration.
  • Titrated tablets from UV-exposed, 70°C heat-exposed, and control groups.
First page of the formal lab report on identifying an unknown weak acid

Identifying an Unknown Weak Acid

Formal lab report, written in LaTeX

Identified the unknown as mandelic acid from its molar mass and pKa

  • Standardized NaOH against potassium hydrogen phthalate to 0.1065 ± 0.0011 M.
  • Located equivalence points with the derivative method and Gran plots; trials agreed within 0.5%.
  • Calculated a molar mass of 147 ± 8 g/mol and a pKa of 3.50 ± 0.06.
Read the report (PDF)