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प्रश्न
Complete flow chart given below.
उत्तर
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संबंधित प्रश्न
Tinning : Tin : : Galvanizing : _________
Give reasons:
Platinum, gold and silver are used to make jewellery.
Explain why rusting of iron objects is faster in coastal areas than in deserts.
Write a chemical equation to show the process of corrosion of iron.
Fill in the following blank with suitable word:
The process of depositing a thin layer of zinc on iron articles is called .............
Why is an iron grill painted frequently?
Name an alloy of copper. State its chemical composition and any one use.
Explain why, when a copper object remains in damp air for a considerable time, a green coating is formed on its surface. What is this process known as?
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of:
(a) hydrated copper sulphate
(b) copper oxide
(c) basic copper carbonate
(d) copper nitrate
Corrosion can be an advantage in some case.Explain ?
Write scientific reasons.
Lemon or tamarind is used for cleaning copper vessels turned greenish.
Find the odd man out:
What are the adverse effects of corrosion?
What is "rusting"? Describe with a labelled diagram an activity to investigate the conditions under which iron rusts.
Answer the following question.
List two properties of alloys.
Give reason.
Copper and brass utensils should be tinned.
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 a reason why rust turns moist red litmus blue.
State whether the statement given below is true or false. If false write the correct statement.
Either oxygen or moisture is essential for rusting.
Write a short note on Alloying.
Which of the following method is used to prevent the accumulation of greenish layer on brass due to corrosion?
When one of the metals in an alloy is mercury the alloy is called _______.
Bronze : _______ : : Stainless steel : Fe + Cr + C
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
Write scientific reason.
On exposure to air, silver articles turn blackish after some time.
What is rust?
Write a molecular formula for rust.
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
State two conditions necessary for rusting of iron.
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
The table shown below gives information about four substances: A, B, C and D.
| SUBSTANCE | MELTING POINT (K) | ELECTRICAL CONDUCTIVITY | |
| SOLID | LIQUID/ AQUEOUS | ||
| A | 295 | Good | Good |
| B | 1210 | Poor | Good |
| C | 1890 | Poor | Good |
| D | 1160 | Poor | Poor |
Identify Ionic compounds from the above given substances.
Identify the correct statement from the following:
Galvanisation is a process used to prevent the rusting of which the following?
State whether the following statements are true or false:
Ships suffer a lot of damage though they are painted.
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
