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प्रश्न
Give reason for the following:
Aqua regia dissolves gold and platinum.
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उत्तर
\[\ce{3HCl + HNO3 -> 2H2O + NOCl + 2[Cl]}\]
Gold in Aqua regia :
\[\ce{Au + 4[Cl] -> AuCl3}\]
Platinum in Aqua regia :
\[\ce{Pt + 4[Cl] -> PtCl4 }\]
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संबंधित प्रश्न
Explain the following:
Concentrated nitric add appears yellow when it is left standing in a glass bottle.
Write an equation for the following conversions A, B, C and D.
What is meant by the following term?
Decrepitation
Write balanced equation and name the product formed when :
Cupric oxide reacts with nitric acid.
How will you prepare Aqua regia from nitric acid?
What do you observe when?
Hydrogen sulphide is bubbled through conc. HNO3?
Write balanced equation for the reaction between nitrogen and oxygen, when lightning strikes.
Write the equation for the laboratory preparation of nitric acid from potassium nitrate and concentrated sulphuric acid.
The figure given below illustrates the apparatus used in the laboratory preparation of nitric acid:
(i) Name A (a liquid), B( a Solid) and C(a liquid).
(ii) write the balanced chemical equation to show how nitric acid undergoes decomposition.
(iii) Write the balanced chemical equation for the reaction in which copper is oxidized by concentrated nitric acid.
X, Y and Z are three crystalline solids that are soluble in water and have a common anion.
To help you to identify X, Y and Z, you are provided with the following experimental observations. Copy and complete the corresponding inferences in (a) to (e).
- A reddish-brown gas is obtained when X, Y and Z are separately warmed with concentrated sulphuric acid and copper turning added to the mixture.
INFERENCE 1: The common anion is the ______ ion. - When X is heated, it melts and gives off only one gas which re-lights a glowing splint.
INFERENCE 2: The cation in X is either ______ or ______. - The action of heat on Y produces a reddish-brown gas and yellow residue which fuses with a glass of the test tube.
INFERENCE 3: The metal ion present in Y is the ______ ion. - When Z is heated, it leaves no residue. Warming Z with sodium hydroxide solution liberates a gas which turns moist red litmus paper blue.
INFERENCE 4: Z contains the ______ cation. - Write the equations for the following reactions:
- X and concentrated sulphuric acid (below 200°C). (One equation only for either of the cations given in INFERENCE 2)
- The action of heat on Y.
- Concentrated nitric acid is added to copper turnings kept in a beaker.
