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प्रश्न
Give reasons:
Platinum, gold and silver are used to make jewellery.
Give a reason for the following:
Silver, gold and platinum are used to make jewellery.
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उत्तर
- Gold, silver, and platinum are the least reactive metals. They do not react with air, water, acids, alkalis, or other gases in the environment, so their shine lasts for years.
- Due to their bright lustre and resistance to corrosion, gold, silver, and platinum are used to make jewellery.
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संबंधित प्रश्न
Write two methods of preventing the rusting of iron.
Choose the correct answer from the options given below:
Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as
A. Smelting
B. Ore-dressing
C. Calcination
D. Bessemerisation
What type of chemical reaction is involved in the corrosion of iron?
What is meant by galvanisation? Why is it done?
Fill in the following blank with suitable word:
The corrosion of copper produces a .............. coating of basic copper carbonate on its surface
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
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.
Name a common metal which is highly resistant to corrosion.
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 ..................................................................
Find the odd man out:
Give a reason why rust turns moist red litmus blue.
Write a short note on Alloying.
Find the odd one out and give its explanation.
Observe the following figure and write the answer of the question.
- Which process is shown in the figure?
- Explain the chemical reaction shown in the figure.
- Write the reactions on anode and cathode.
Give the equation for the formation of rust.
Amalgam is an alloy of ____________.
The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.
The substance not likely to contain CaCO3 is:
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
