Purchase Solution

# Calculating pH, Ka, grams, and amounts of an acid for making a buffer

Not what you're looking for?

1. Calculate the pH of a solution which is 0.428 M in oxalic acid and 1.44 M in oxalate.

2. What is the pH of a solution that is 45.5 mM in acetic acid and 1.11 M in acetate?

3. A solution which is 3.19X10 to the -3 M in an acid (HA) and 6.78x10 to the -3 M in its conjugate base (A-) is found to have a pH of 8.65. What is the Ka of the acid?

4. Calculate the number of grams of NaH2PO4 (MW=120.0) and the number of grams of Na2HPO4 (MW=142.0) that should be weighed out and dissolved to 1 L to give a 100 mM solution in total phosphate at pH=7.50.

5. Calculate the amounts of formic acid and formate that must be used to make 1 L of buffer at pH= 3.80 and that is 250 mM in total formic acid / formate.

##### Solution Summary

This solution is provided in 805 words in an attached .doc file. It describes buffers and buffer systems, as well as pKa and the Hendersen-Hasselbalch equation.

##### Identifying Variables in Science Experiments, Part 2

Using sample experiments, test yourself to see if you can identify independent, dependent, and controlled variables. Identifying variables is key in understanding and developing experiments. The questions are biology related, but this can be applied to any area of science.

##### The Transfer of Energy in an Ecosystem

This quiz will assess your knowledge of how energy is transferred in an ecosystem and the different levels of trophic organization.

##### Biochemistry Basics

A refresher quiz to test your knowledge of basics concepts of biochemistry.

##### Vision and Oculomotor Control

This quiz will test the student's knowledge of the neural underpinnings of the visual system and its central pathways.

##### BIOLOGY

Basics in biology