Behavioral Dairy Chemist Interview Questions & Answers:

1. Tell me how Many Breeds Of Dairy Cattle Are There?

There are six main breeds of dairy cows: Ayrshire, Brown Swiss, Guernsey, Holstein, Jersey and Milking Shorthorn. A seventh, Red and White, is a variation of the Holstein breed.

2. Please tell me the formula to calculate pH of a solution?

In order to calculate the pH of a solution you have to use the formula pH= -log [H+] or pH = -log [H3O+]

3. Please tell me what is Avogadro's law?

According to Avogadro's law, at same temperature and pressure equal volume of gases contains the same number or molecules regardless of the chemical nature and physical properties.

Avogadro's number = 6.023 X 10 (-23)

4. Please tell me what is buffer?

A buffer is an aqueous solution which has highly stable pH. It is a blend of a weak acid and its conjugate base or vice versa. On adding small amount of base or acid to buffer, its pH hardly changes.

5. Please tell me what is oxidation and reduction reaction?

☛ Oxidation = When there is a loss of hydrogen or electrons, OR gain of oxygen is known as Oxidation reaction.
☛ Reduction = When there is a gain of hydrogen or electron OR loss of oxygen is known as reduction reaction
Example of oxidation-reduction reaction is observed in human body, when an electron is transferred into the cell and oxidation of glucose take place from which we get the energy.

6. Tell me do you know how buffer works?

In buffer when hydrogen ion is added, it will neutralized by the base in buffer. Hydroxide ion will be neutralized by the acid. On the overall pH of the buffer solution, these neutralization reactions will not show much effect.

While when you select an acid as a buffer solution, try to use an acid acid that has a pH closed to your desired pH. This will help your buffer to achieve nearly equivalent amount of acid and conjugate base, so that it will enable to neutralize as much as H+ and OH -.

7. Tell me is Organic Milk Fresher Than Regular Milk?

Probably not. Most milk, including organic and regular milk, is delivered to stores within a few days of milking. However, some organic milk has an extended shelf life if it has undergone ultra-high temperature pasteurization.

8. Tell me what is the difference between Molarity and Normality?

Both techniques are used to the amount of chemical present in the solution. However they are almost similar but differs in

Molarity:
☛ Molarity is used to know the total amount of molecules in a 1 litre solution
☛ It is expressed as moles of a compound per litre of solution

Normality:
☛ Normality is used to know the total number of reactive units in 1 litre of solution
☛ It is expressed in equivalent per litre

9. Please explain what is titration?

Titration is a process to determine the molarity of a base or an acid. In this process a reaction is carried out between the known volumes of a solution with a known concentration, against the known volume of a solution with an unknown concentration.

10. Explain what is the difference between fractionation and distillation?

Both methods are used to separate the components present in the solution based on the melting points

☛ Distillation : This technique is used when boiling point of chemicals are different in the mixtures
☛ Fractionation : This technique is used when boiling point of chemicals are close to each other in the mixtures