Probing pH

Posted on May 19, 2010

Students use probe to test pH of lemon juice

Students in Lynn Bastoni’s seventh grade science class have put away the old pH testing strips that many of us are familiar with in favor of high-tech pH probes.

During their study of acidity and basicity, students filled a beaker with water and slowly added lemon juice. A probe connected to students’ computers was inserted into the solution. As the acidity changed, students were able to see the change in real time as a graph was updated on their computer screens. They then repeated the procedure using ammonia instead of lemon juice.

Comparing the graphical representations of both solutions allowed the students to draw conclusions about the acidity and basicity of each one in a way that the pH strips of old could not.