pH Scale And Standard Curve

Question 1

How is the concentration of hydrogen ions determined?

Answer 1

By measuring the current generated in an electrochemical cell when the ions migrate to oppositely charged electrodes

Question 2

What is a buffer solution?

Answer 2

a solution that changes pH only slightly when small amounts of a strong acid or a strong base are added

Question 3

What does a buffer contain

Answer 3

A weak acid with its salt (conjugate base)

OR

A weak base with its salt (conjugate acid)

Question 4

How does a buffer solution work?

2

Answer 4

The acid component of the buffer can neutralize small added amounts of OH-,

The basic component can neutralize small added amount of H3O+

Question 5

What is an assay?

Answer 5

An assay is a method used to measure something

Question 6

What is the biuret method of preparing an assay?

2

Answer 6

The blue reagent (biuret reagent) turns violet in the presence of proteins, and changes to pink when combined with short-chain polypeptides

Peptide-bond react with alkaline copper-sulfate to produce a blue/violet colour

Question 7

Define a response curve.

Answer 7

A response curve is a plot of the assay responses versus a series of known analyte concentrations

Question 8

Define a standard curve

Answer 8

Linear portions of response curves are called standard curves

Question 9

Define Beer’s Law

Answer 9

The relationship between absorbance and the concentration of a compound is linear except at very low and high concentration and in impure solutions