Analyze pCO2 through pressure, solubility, and bicarbonate modes. Switch units quickly and compare method outputs. Download results instantly for lab records and team reviews.
| Mode | Input Snapshot | Expected pCO2 | Notes |
|---|---|---|---|
| Gas Mixture | 5% CO2, 1 atm, no wet correction | 38.0000 mmHg | Useful for chamber or blend verification. |
| Henry Law | 1.20 mmol/L dissolved CO2, kH = 0.034 mol/L/atm | 26.8200 mmHg | Back-calculates gas-side pCO2 from dissolved CO2. |
| Henderson–Hasselbalch | pH 7.40, HCO3− 24 mmol/L, α 0.03, pKa 6.10 | 40.0900 mmHg | Common reference setup for blood chemistry checks. |
1) Gas Mixture: pCO2 = xCO2 × Ptotal. If wet gas correction is enabled, dry pressure is used: pCO2 = xCO2 × (Ptotal − PH2O).
2) Henry Law: Dissolved carbon dioxide and gas pressure are linked by C = kH × pCO2. Rearranged form for pressure is pCO2 = C / kH.
3) Henderson–Hasselbalch: pCO2 = [HCO3−] / (α × 10^(pH − pKa)). This mode estimates pCO2 from bicarbonate chemistry and pH.
Tip: In Gas Mixture mode, enable wet correction when your gas sample contains water vapor and total pressure should be adjusted to dry pressure.
Partial pressure of carbon dioxide is a core indicator in laboratory chemistry, process gas blending, and aqueous equilibrium studies. This calculator supports rapid checks across gas, dissolved, and bicarbonate-derived inputs, so teams can compare assumptions before reporting. For example, a five percent CO2 blend at one atmosphere yields about thirty eight millimeters of mercury, which matches many calibration demonstrations and helps validate pressure unit conversions.
Gas mode converts the entered total pressure into atmospheres, applies the CO2 fraction, and optionally subtracts water vapor pressure for dry-gas correction. This is useful when incubators, glove boxes, or reactors operate with humid streams. If total pressure is one hundred one point three two five kilopascals and water vapor is three point one seven kilopascals, the effective dry pressure falls slightly, reducing calculated pCO2 and improving consistency with dry analytical instruments.
Henry mode connects dissolved CO2 concentration and gas-side pCO2 using the relation C equals kH multiplied by pCO2. When concentration is known, the calculator back-calculates pressure; when pressure is known, it estimates dissolved CO2. Using a Henry constant near zero point zero three four moles per liter per atmosphere at room conditions, a pCO2 around forty millimeters of mercury predicts a dissolved concentration close to one point eight millimoles per liter.
The Henderson–Hasselbalch option estimates pCO2 from pH, bicarbonate concentration, alpha solubility, and pKa. This method is frequently used for blood-gas style chemistry checks and educational demonstrations. With pH seven point four, bicarbonate twenty four millimoles per liter, alpha zero point zero three, and pKa six point one, the result is roughly forty millimeters of mercury, which sits inside the common thirty five to forty five reference interval.
For reliable reporting, users should confirm input units, sample temperature assumptions, and whether pressure readings are wet or dry. The calculator displays formula steps, unit conversions, and export files to support audits and peer review. A practical workflow is to calculate in millimeters of mercury, compare the kilopascal value, then archive CSV or PDF outputs with instrument batch numbers, operator initials, and collection timestamps for traceability purposes.
1) Which mode should I use first?
Use Gas Mixture when you know total pressure and CO2 fraction, percent, or ppm. It is ideal for chambers, reactors, gas cylinders, and blended streams where composition is measured directly.
2) When should wet gas correction be enabled?
Enable wet correction when the sample pressure includes water vapor. The calculator subtracts vapor pressure to estimate dry-gas pCO2, which better matches dry analyzers and reporting standards.
3) Why does the Henry constant matter so much?
Henry constants vary with temperature, salinity, and source convention. Use a value and unit consistent with your method, then document the temperature so later comparisons remain valid.
4) Is Henderson–Hasselbalch mode only for medical use?
The Henderson–Hasselbalch mode estimates pCO2 from pH and bicarbonate chemistry. It is useful for educational chemistry checks and blood-gas style calculations, but results depend strongly on alpha and pKa assumptions.
5) Can I export results in different pressure units?
Yes. The result panel shows pCO2 in atm, kPa, mmHg, bar, and psi. Choose a preferred display unit, then use CSV or PDF export for records and reviews.
6) Does this tool handle instrument calibration errors?
No. This tool performs deterministic calculations from the values you enter. It does not correct sensor drift, temperature compensation errors, or sampling contamination without proper input assumptions.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.