Advertisements
Advertisements
Question
When one of the metals in an alloy is mercury the alloy is called _______.
Options
amalgam
sodium amalgam
zinc amalgam
all the above
Solution
When one of the metals in an alloy is mercury the alloy is called amalgam.
APPEARS IN
RELATED QUESTIONS
Which metals do not corrode easily?
Answer the following question.
What are alloys?
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Give reasons:
Platinum, gold and silver are used to make jewellery.
Two methods by which rusting of iron can be prevented are ______ and ______.
Explain how painting of an iron gate prevents it from rusting.
Explain why Iron sheets are coated with zinc during galvanization.
What type of chemical reaction is involved in the corrosion of iron?
Fill in the following blank with suitable word:
The corrosion of iron is called ................
Name any two metals which do not corrode easily.
Give the constituents and one use of brass.
Name a common metal which is highly resistant to corrosion.
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?
No chemical reaction takes place when granules of a solid, A, are mixed with the powder of another solid, B. However when the mixture is heated, a reaction takes place between its components. One of the products, C, is a metal and settles down in the molten state while the other product, D, floats over it. It was observed that the reaction is highly exothermic.
(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.
(ii) Mention any two types of reactions under which above chemical reaction can be classified.
Complete the process of iron rusting by filling the blanks. Suggest a way to prohibit the process.
The iron rust is formed due to........................... reaction. Different
regions on iron surface become anode and cathode.
Reaction on anode region :
`F_e(s) → Fe^(2+) (aq) +2e^-`
Reaction on anode region :
`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `
When Fe2+ ions migrate from anode region they react with ................... to form Fe3+ ions.
A reddish coloured hydrated oxide is formed from ............... ions. It is called rust.
`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `
A way to prevent rusting ..................................................................
Answer the following question.
a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.
What is done to prevent corrosion of metals?
Choose the correct alternative and rewrite the following:
Iron is _____________________.
Write three methods of preventing rusting of iron.
What is "rusting"? Describe with a labelled diagram an activity to investigate the conditions under which iron rusts.
Give reason.
An iron article should be given a coat of paint
Give a reason why rust turns moist red litmus blue.
Stainless steel is an alloy of _______.
Pressure cooker : Anodizing : : Silver plated spoons : _______
Bronze : _______ : : Stainless steel : Fe + Cr + C
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
Match the columns.
| Group A | Group B |
| 1) Electroplating | a) Pressure cooker |
| 2) Anodising | b) Silver plated spoons |
| c) Coating of tin on copper | |
| d) Coating of Zinc on iron |
Write scientific reason.
On exposure to air, silver articles turn blackish after some time.
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
What is rust?
Which among the following alloys contain mercury as one of its constituents?
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
