Contact
Get in touch
There is no contact form here on purpose. A form needs a server to receive it, this site is static files with no backend, and a form that looks like it submits but quietly does nothing is worse than no form at all. Email works and it reaches a person.
Reporting a result you disagree with
This is the most useful message you can send. Include four things and it can be checked in a couple of minutes:
- Which page or mode you used, for example percent yield or stoichiometry.
- The exact values you entered, including the units you picked.
- The answer the calculator gave.
- The answer you expected, and where it came from if it was a textbook or a marking scheme.
Before sending, it is worth checking the significant-figure setting. A disagreement in the last digit is usually the rounding convention rather than an error, and the about page explains which convention is applied and how to switch it off.
Other things worth writing about
- A missing unit. The main calculator handles 14 mass and amount-of-substance units. If yours is not among them, say which one and what field you need it in.
- A reaction example. Worked examples are more useful when they match reactions people actually run. Send the equation and the masses and it can be added to the examples page.
- An accessibility problem. Anything that does not work with a keyboard, a screen reader or at high zoom is treated as a bug.
- A chemistry correction. If a reaction, molar mass or yield band on the site is wrong, that takes priority over everything else.
What this site cannot help with
Requests to check a full lab report, complete an assignment or advise on a specific experimental procedure are outside what a calculator can sensibly do. The tools show their working precisely so you can follow each step yourself, and your supervisor or course tutor is the right place for procedure-specific questions.