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प्रश्न
What are anti-oxidants? Why are they added to fat and oil containing foods?
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उत्तर
Antioxidants are reducing agents that prevent oxidation of fats and oils. They are added to fatty and oily foods to prevent them from turning rancid (i.e., change in taste and smell of food) due to oxidation. Example: Butylated hydroxyanisole (BHA).
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संबंधित प्रश्न
When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.
Define reduction.
MULTIPLE CHOICE QUESTIONS
The process of adding oxygen to a substance is called
- oxidation.
- reduction.
- displacement.
- hydrogenation.
In the following reaction: A+ + B → A + B+. Write half-reactions for this reaction and name:
- oxidizing agent
- substance oxidized
- reducing agent
For the reaction PbO + H2→ Pb + H2O, which of the following statements is wrong?
Choose terms from the options given in brackets to complete this sentence.
When CuO reacts with hydrogen,………………… is reduced and ……………….is oxidized to ………………….
(CuO, H2, Cu, H2O)
Name:
a substance that oxidizes concentrated HCl to chlorine.
Name:
a gas that is oxidizing as well as a reducing agent.
Complete and balance the following equation:
Zn +_________________→ZnCl2 + H2
Complete and balance the following equation:
\[\ce{K + H2O -> }\]________+ ________
State a reason why, when hydrogen is passed over heated copper oxide, the resultant product formed, differs in colour from the original reactant.
\[\ce{MnO2 + 4HCl -> + 2H2O + Cl2}\]
Identify the substance oxidized in the above equation.
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
The reaction of sodium metal is found to be highly explosive
Explain this observation giving suitable reason.
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid whereas copper does not. Explain why?
The tendency of atoms to have eight electrons in the outer shell is known as ______.
Find the oxidation number of the element in the following compound.
A1 in AlCl3
When hydrogen gas is passed over black copper oxide, a reddish-coloured layer of copper is formed.
Answer the questions that follow based on this reaction.
- Write the equation.
- What type of reaction is it?
- Complete the blanks:
In this reaction, an oxygen atom goes away from CuO (copper oxide), which means that ______ of copper oxide takes place, whereas a hydrogen molecule takes up an oxygen atom and water (H2O) is formed, meaning ______ of hydrogen takes place.
It is recommended to use air tight containers for storing oil for a long time.
The metallic oxide which can be reduced by using common reducing agents is ______.
