Dilution and Pipetting Lesson Using Food Dyes

In this lesson students learn how to use micropipettors to accurately measure small volumes of liquids and perform dilutions using food dyes. Students dilute four food dyes at 10X concentration to 1X working stocks. Using the formula c1v1=c2v2 each student completes a table requiring four dilution calculations for different final volumes. Using the values they generated, students make the solutions of 1X food dye. Reference solutions furnished by the instructors provide students with immediate feedback and self-assessment. To practice adjusting the micropipette volumes, students combine their 1X solutions to produce four new colors. Comparison of these to reference solutions provides students with immediate feedback. This lesson works for students in grades 6-14 and adult learners in continuing education workshops. It requires about an hour and after they complete the lesson, students have confidence to move on to more challenging solution preparations with colorless reagents. 

在本课程中，学生将学习如何使用微量移液器精确测量微小体积的液体并使用食用色素进行稀释。学生们将四种食用色素以10倍浓度稀释至1倍工作浓度。通过使用公式c1v1=c2v2，每位学生完成一个表格，该表格需要针对不同的最终体积进行四次稀释计算。利用他们生成的数值，学生们制备出1倍浓度的食用色素溶液。由讲师提供的参考溶液为学生提供了即时反馈和自我评估的机会。为了练习调整微量移液器的体积，学生们将他们的1倍浓度溶液混合，以产生四种新的颜色。将这些新颜色与参考溶液进行比较，为学生提供了即时反馈。本课程适用于6至14年级的学生以及继续教育研讨会中的成人学习者。课程时长约为一小时，学生在完成课程后，将能够自信地继续进行更具有挑战性的无色试剂溶液的制备。