A High School Chemistry Teacher Visits Lower Science!

Ruth Whiteside, Sophie Cross' (2-231) grandmother and former high school chemistry teacher, came to science last week to show us....

What happens when we mix substances together?

The class mixed sodium bicarbonate with calcium cloride in a ziplock bag.  

Then Sophie's Nana added water and bromothymol blue (an indicator) into the bag with the two solids and sealed the bag. We mixed, we watched, we even listened to the bag!

 The mixture bubbled and the bag got bigger!

 The color of the mixture changed
 from blue to yellow!

 We opened the bag and tested the gas with a
lighted splint which went out.

We gently blew on a lighted splint and it went out too! Lastly we all blew through a straw into a cup filled with water and bromothymol blue and saw the liquid turn from blue to yellow!

 The liquid started out blue....

 and after about a minute, the liquid turned yellow!

The gas we exhale contains the same gas as the gas in the ziplock bag - carbon dioxide!

The visit was a huge success!  The class loved creating "potions" and seeing reactions all the while getting to wear the safety goggles!