acids/bases

Using Visual BCA Tables to Teach Limiting Reactants

Melissa Hemling | Wed, 04/26/2017 - 11:10

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Looking for a better way to teach stoichiometry? Melissa incorporates modeling into BCA tables.

Do you have a favorite acid-base titration lab?

Allison Tarvin | Sat, 03/11/2017 - 10:11

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HCl and NaOH, a strong acid - strong base titration? Citric acid and NaOH, a weak, triprotic acid - strong base titration? Do your students standardize the NaOH solution as a first step?

Real World Application: Drain Cleaners - Should I use them?

Dan Meyers | Fri, 10/16/2015 - 15:01

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Common drain cleaners consist of water, sodium hypochlorite (bleach) and sodium hydroxide (base) and/or potassium hydroxide (base). Bases are caustic (caustic loosely means to gnaw or eat away at) and can cause corrosion in metal pipes. Wouldn’t you know, our house has PVC piping through the fixtures that dump into a 45 year old cast iron pipe. The cast iron pipe is old and currently shows signs of surface rust and corrosion to the point where the pipe appears to be leaking then sealing itself in several spots. Not to mention the interior of the cast iron pipe may not be completely open, thus, not permitting a fast flow in drainage. Good news: a home warranty is being taken advantage of to hopefully replace the cast iron pipe with a PVC pipe.

Wash Your Blues Away - With Chemistry!

Tom Kuntzleman | Thu, 09/03/2015 - 18:31

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How does the blue to white color change occur in the foam of Scrubbing Bubbles or KABOOM Brand cleaners? Watch this video and find out.

My First Day Demonstration

Michael Morgan | Fri, 07/31/2015 - 19:23

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Michael Morgan has used this demo for over 25 years! His students from 20 years ago still remember the first day of chemistry!

Lab 20 aka Check the Solution!

Sarah Kong | Thu, 04/16/2015 - 19:29

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Last night I had the opportunity to do another lab that I wrote with my students. It is so exciting to see something go from words on a screen to a group of students working together in a laboratory. I learned so much as I walked around the room last night. Here are a few highlights:

Mass of a Reaction Product

David Licata | Wed, 10/29/2014 - 21:41

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Students combine sodium carbonate and hydrochloric acid generating carbon dioxide gas which is allowed to escape. They measure the actual yield of carbon dioxide produced (missing mass), calculate the theoretical yield using stoichiometry, and then the percent yield. Students understand that 100% yield is the most appropriate answer (based on the Law of Conservation of Mass), so after considering the meaning of significant figures and the uncertainty of their measurements they are asked to decide if they did (or did not) get an answer that might indicate the validity of the Law.