Rancidity

Q.

Define rancidity.

Q.

What is rancidity?

Q.

What is Rancidity? Mention 4 ways to prevent it.

Q. What happens when milk is left at room temperature?

Q.

What Is the formula of Corrosion of Silver?

Q. Why does a copper vessel get covered with a green coating in rainy season?

Q.

What happens when food materials containing fats and oils are left for a long time? List two observable changes and suggest three ways by which this phenomenon can be prevented.

Q.

What is rancidity? Give some examples and some precautions also.

Q.

Why do potato chips manufacturers fill the packet of chips with nitrogen gas

Q.

What are the main causes of Corrosion?

Q.

(a) Explain the term "rancidity". What damage is caused by rancidity ?

(b) What type of chemical reaction is responsible for causing rancidity ?

(c) State and explain the various methods for preventing or retarding rancidity of food.

Q.

What are anti-oxidants ? Why are they added to fat and oil containing foods ?

Q.

Explain two ways by which food industries prevent rancidity

Q. Question 14

Which of the following gases can be used for storage of fresh sample of an oil for a long time?

a) Carbon dioxide or oxygen
(b) Nitrogen or oxygen
(c) Carbon dioxide or helium
(d) Helium or nitrogen

Q.

Define:

1) Oxidation reaction

2) reduction reaction

3) neutralization reaction

4) precipitation reaction

Q.

Why a magnesium

ribbon should be cleaned before burning?

Q.

What is the general name of the chemicals which are added to fat and oil containing foods to prevent the development of rancidity ?

Q.

Brass gets discolored in the air because of the presence of which of the following gases?

1. Oxygen

2. Hydrogen sulfide

3. Carbon dioxide

4. Nitrogen

Q. 19. Define, rancidity. What kind of substances are used to prevent rancidity? Explain any three methods to prevent rancidity.(5 marks)

Q.

Explain why, food products containing fats and oils (like potato chips) are packaged in nitrogen.

Q.

Which term is used to indicate the development of unpleasant smell and taste in fat and oil containing foods due to aerial oxidation (when they are kept exposed for a condiderable time) ?

Q.

What metals dont oxidize?

Q.

Write method to prevent rancidity? What is rancidity?

Q.

How do copper silver and iron corrode when exposed to the atmosphere?

Q.

How can we prevent rancidity? [5 MARKS]

Q.

What metal turns green when oxidized?

Q. When food containing fat or oil is not used and left for long time, their smell and taste changes.Name the process which is responsible for the change.List two methods to prevent or slow down the above change

Q.

Use of BHA and BHT in butter ( that is part of rancidity in the chapter)

Q. State the reasons for the following-(3 marks)
(a) Iron articles loose their shine gradually.
(b) Food should be kept in air tight containers.
(c) Apperance of black coating on silver whenever it is exposed to air.

Q.

What is difference between corrosion and rusting ?