October 2022: Hosting upgrade, login issues, and bug fixes

Hello, everyone! I hope your new school year has started off well with as few bumps and disruptions as possible. Despite enduring two lockdowns at school last month, I’m having a lot of fun teaching Chemistry again because I get to do neat stuff like making “gold” pennies:

video of a zinc-coated penny being turned to brass

This is from the Alchemy Lab that I’ve been doing for decades and which is a student favorite – here are the directions if you’re interested! There are lots of ways to do the lab, but this year I had my students heat their pennies on hotplates instead of in Bunsen burner flames, and that seemed to work much better. (On a side note: today when I was testing Bunsen burners and bleeding air that had built up in the gas lines in the lab over the summer, one of them suddenly shot flames out from the bottom and burned off some of the hair on my knuckles, so I’m happy to stick with hotplates instead! πŸ”₯)

Since the start of September, over 20 schools have either signed up for new site licenses or renewed from last school year, so I wanted to thank you all for your continued support of! These site licenses allowed me to upgrade to faster web hosting last month to make the site run faster. Speaking of the upgrade…

September 21st hosting upgrade (or, “The best laid plans of mice and men”)

I’ve noticed that the site was getting WAY more traffic in August 2022 than it did in August 2021, and there were more issues with “site not responding” errors due to my web hosting tier being overwhelmed, so I used money from site licenses to upgrade my web hosting. Based on the documentation on my hosting service’s website, it seemed really easy – contact sales, pay for the upgrade. The process probably took me a total of five minutes, at most!

Unfortunately, the sales team must not have communicated with the tech support team, because while the guts of got moved to a new server and IP address, none of the domain name service (DNS) entries got updated, so for about 24 hours, loading up would take you to the old server, not the new one that I’d paid for. When I finally realized what was going on the following day, it took about two hours of tech support chat and phone calls to get everything sorted out.

Without getting into the gory details, DNS updates propagate across the world from the server they’re originally changed on, one server connection at a time, so it can take up to 48 hours for the changes to take effect everywhere in the world. This means that for about a day and a half, some users were accessing the new, faster hosting, while others were accessing the old, slower hosting. The quizzes all acted the same, but some quiz results were saved to the old server and then “disappeared” as soon as the DNS update went through.

The good news is that I still had access to the old server, so I waited until DNS had fully propagated by Saturday afternoon and then copied those missing results over to the new server. I only copied over important quiz result and user data, so you can see switchover clearly on this graph of site visits over the last 20 days since I didn’t bother copying the database table with those stats:
graph of visits over the past 20 days

If it still appears that any of your students’ quiz results are missing from the Dashboard, please let me know and I’ll double check for you! I know how much students hate it when a teacher loses their work, so I don’t want that to happen to any of your students on

Student login issues

I’ve been hearing from a number of teachers with site licenses to the Dashboard that their students are sometimes having problems accessing during the day. There are two primary reasons this has been happening: an overall increase in the number of visitors to the site, and the security software interpreting failed student logins as hacking. I’ve upgraded the web hosting to address the first, as I mentioned earlier, but the second issue is a little more complicated.

Basically, if a student repeatedly attempts to log in with an incorrect password (or no password at all) and fails 10 times in a row, the site’s security software will block that student’s IP address for 5 minutes. The idea is to prevent “brute force” hacking, which unfortunately is very common on sites like that are based on the WordPress content management system. (You would not believe how frequently the website is attacked from all over the world – it’s a constant issue.) This student behavior may be unintentional or completely intentional, but the effect is the same, and it can prevent your other students from accessing the site if they have the same IP address, which is common for school districts.

Unfortunately, I can’t disable the security software, because would get hacked within days, if not hours. However, to prevent this sort of lockout from happening to you and your students, there are two steps you can take. First, you can send me your school or district IP address at school by googling “What’s my IP address” and send me the number. I’ll whitelist your IP address so that any failed login attempts are ignored by the site security software. Make sure you do this at school, not at home! The second thing you can do is monitor your students when they’re logging in to to make sure they’re not just clicking the login button repeatedly. The good news is that their login sessions last for 30 days since the last time they’ve accessed the site, so between that and the “Login with Google” button, I’m hoping this won’t continue to be a serious issue going forward.

New features & bug fixes

No new quizzes with this update, but thanks to your feedback, I’ve made some serious bug fixes that were impeding assignment creation on the Dashboard. Here’s a summary of the bug fixes:

  • disabled autocomplete in all form inputs for all quizzes so that entering answers is a cleaner experience for students (suggested by my son!)
  • students couldn’t load all of the options to practice a quiz if an assignment already existed for it (thanks, Danny!)
  • threshold, notes, instructions and custom name were being wiped out in the database when a new assignment was created in the Dashboard (thanks, Ryan!)
  • “lock after close” could be set without a value for “date closed” when creating & editing assignments (thanks, Krisha!)
  • can’t edit quiz-specific options for an assignment in the Dashboard if it has a due date (thanks, Darlene!)
  • archived classes were showing up in filter menu on the Results page in the Dashboard (I found this one)
  • + other under-the-hood Dashboard improvements
  • answers on the Concentrations of Solutions Quiz that were correctly rounded to the hundredths place were marked as incorrect (thanks, Karen!)
  • the Lewis Dot Structures Quiz wasn’t identifying all correct student responses, so now the quiz just counts the number of checkboxes to match the correct number of valence electrons (thanks, Nick & David!)
  • some two-step conversion problems in the SI Conversions Quiz were converting to the same unit πŸ€¦πŸ»β€β™‚οΈ (thanks again, Darlene!)

Help me share with the world!

If you like using, there are three quick and easy things that you can do to help me promote the site!

  • Follow @ChemQuizDotNet on Twitter and Facebook and share my updates with your fellow Chemistry teachers!
  • Tell another Chemistry teacher about and encourage them to try out the Dashboard!
  • Add your school to the list of supporters on the About page by going to the Dashboard, click on “Your Info” in the top menu bar, check the box next to “Display School on“, and click the “Update Your Info” button.

There was a funny moment this weekend when our oldest kid, who’s a first-year student at Ohio University, was visiting us up in Kent this past weekend. Our son is a freshman taking Advanced Chemistry with a colleague of mine at the high school where I teach, and he was complaining about how he missed some questions on a recent sig figs quiz in class. Unprompted by me, our oldest said, “Use ChemQuiz to practice sig figs, it’s easy!” I wish I’d had my phone in hand so I could have recorded the exchange for future advertising purposes, but all I have is the memory. πŸ˜‚

Thanks again to everyone for your continued support of and for your patience with the bumps in the road that have occurred recently. Please feel free to get in touch with me if you have any questions, suggestions for improvement, or problems with the site. Take care and stay safe!


PS: If you didn’t see the September newsletter because of email delivery issues, it’s available here!