Advertisements
Advertisements
प्रश्न
State the various characteristics of chemical reactions.
Advertisements
उत्तर
- Evolution of gas: Zinc and dilute sulphuric acid react to form zinc sulphate with the evolution of hydrogen gas.
- Formation of precipitate: Sulphuric acid and barium chloride react to form white precipitates of barium sulphate.
- Change in colour: The purple colour of the potassium permanganate solution, upon the addition of citric acid, changes to a colourless solution.
- Change in temperature: Barium hydroxide and ammonium chloride react to form barium chloride, ammonia and water. This is an endothermic reaction in which heat is absorbed, causing the temperature to fall.
- Change in state: Combustion of candle wax (solid) leads to the formation of water (liquid) and carbon dioxide (gas).
APPEARS IN
संबंधित प्रश्न
Complete and balance the following equation:
\[\ce{Ca(OH)2 + {..........} -> CaCO3 + H2O}\]
Balance the following equation:
\[\ce{Mg(OH)2 + HCl -> MgCl2 + H2O}\]
What are the various ways in which a chemical equation can be made more informative? Give examples to illustrate your answer.
Explain, with an example, how the physical states of the reactants and products can be shown in a chemical equation.
Give one example of a chemical reaction characterised by the formation of a precipitate.
An acid which can decolourise purple coloured potassium permanganate solution is ______.
Balance the following chemical equation :
Na2CO3 + HCl → NaCI + H2O + CO2
Balance the following equation. Also name the product formed.
N2 + H2 → NH3
Complete the following equation:
CH2 + H5OH `("Hot Conc." H_2SO_4)/`>
Balance the equation stepwise.
H2S2O7(l) + H2O(l) → H2SO4(l)
Write the chemical equation for the following word equation and balance them.
Sodium reacts with water to form sodium hydroxide and hydrogen
Balance the following equation:
PbO + NH3 → Pb + H2O + N2
Name the substance that is getting oxidised in the thermit process.
A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – copper carbonate.
A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – mercury [II] oxide.
In certain reaction an insoluble solid called precipitate is formed. State the colour and name of the precipitate formed in the following reaction involving addition of:
Copper [II] sulphate to sodium hydroxide.
Name the following:
A catalyst which increases the rate of a chemical reaction.
Give a balanced equation by partial equation method, [steps are given below].
The reaction of excess ammonia with chlorine – Ammonia as a reducing agent
- Ammonia first reacts with chlorine to give hydrogen chloride and nitrogen.
- Hydrogen chloride then further reacts with excess ammonia to give ammonium chloride.
Complete the given chemical reaction.
\[\ce{CuSO_{4(aq)} + Fe_{(s)} ->}\]______ + ______
A dilute ferrous sulphate solution is gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?
