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प्रश्न
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
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उत्तर
Because silver amalgam melts at low temperatures and may easily fill cavities, it is used to fill cavities.
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संबंधित प्रश्न
Tinning : Tin : : Galvanizing : _________
Explain the term corrosion.
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Explain why rusting of iron objects is faster in coastal areas than in deserts.
State two conditions for the rusting of iron.
Why is an iron grill painted frequently?
Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
Give the constituents of brass.
What are the special properties of stainless steel?
Name an alloy of copper. State its chemical composition and any one use.
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
A common metal which is highly resistant to corrosion is ______.
Four metals P, Q, R and S are all obtained by the reduction of their oxides with carbon. Metal P is used to form a thin layer over the sheets of metal S to prevent its corrosion. Metal Q is used for electroplating tiffin boxes made of metal S whereas metal R is used in making car batteries. Metals Q and R form an alloy called solder. What are metals P, Q, R and S? How have you arrived at this conclusion?
Name the metal which is a constituent of plant pigment?
Compare roasting and calcination.
Observe the following picture a write down the chemical reaction with the explanation.
What are the adverse effects of corrosion?
Give reason.
A wooden article should be polished.
Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.
Give reason for the following:
A suspension of rust is basic in nature.
_______ is an alloy made from iron, carbon and chromium.
Corrosion of silver causes a black layer of _______.
When one of the metals in an alloy is mercury the alloy is called _______.
Pressure cooker : Anodizing : : Silver plated spoons : _______
Find the odd one out and give its explanation.
Write the name.
An alloy of copper and tin-
Explain concept with example/explain with the help of a balanced equation.
Corrosion
Observe the following diagram and give answers.
- Name this method of prevention of corrosion.
- For prevention of which metal this method is used?
- What is used as anode in this method?
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
Give the equation for the formation of rust.
Amalgam is an alloy of ____________.
Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
Gold plated ornaments is the example of ______.
Explain the chemical reactions in rusting of iron.
Describe two changes that are harmful. Explain why you consider them harmful. How can you prevent them?
