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प्रश्न
Define: Endothermic reaction
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उत्तर
The reactions in which heat is absorbed are called endothermic reactions. The reactants absorb heat for form products.
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संबंधित प्रश्न
Balance the following chemical equation.
\[\ce{BaCl2 + H2SO4 -> BaSO4 + HCl}\]
How will you indicate the following effect in a chemical equation?
A solution made in water.
Complete and balance the following equation:
Ca(OH)2 + .......... \[\ce{-> CaCO3 + H2O}\]
Correct and balance the following equation:
\[\ce{Ca + H2O -> CaOH + H}\]
Balance the following equation:
\[\ce{BaCl2 + H2SO4 -> BaSO4 + H2O}\]
Carbon monoxide reacts with hydrogen under certain conditions to form methanol (CH3OH). Write a balanced chemical equation for this reaction indicating the physical states of reactants and product as well as the conditions under which this reaction takes place.
State one characteristic of the chemical reaction which takes place when dilute hydrochloric acid is added to sodium carbonate.
State one characteristic of the chemical reaction which takes place when dilute sulphuric acid is added to barium chloride solution.
Give one example of an endothermic reaction.
You are given the solution of lead nitrate. In order to obtain a yellow precipitate you should mix with it a solution of ______.
Which of the following is not an endothermic reaction?
When the solution of substance X is added to a solution of potassium iodide, then a yellow solid separates out from the solution.
- What do you think substance X is likely to be?
- Name the substance which the yellow solid consists of.
- Which characteristic of chemical reactions is illustrated by this example?
- Write a balanced chemical equation for the reaction which takes place. Mention the physical states of all the reactants and products involved in the chemical equation.
When metal X is treated with a dilute acid Y, then a gas Z is evolved which burns readily by making a little explosion.
- Name any two metals which can behave like metal X.
- Name any two acids which can behave like acid Y.
- Name the gas Z.
- Is the gas Z lighter than or heavier than air?
- Is the reaction between metal X and dilute acid Y exothermic or endothermic?
- By taking a specific example of metal X and dilute acid Y, write a balanced chemical equation for the reaction which takes place. Also indicate physical states of all the reactants and products.
A metal X forms a salt XSO4. The salt XSO4 forms a clear solution in water which reacts with sodium hydroxide solution to form a blue precipitate Y. Metal X is used in making electric wires and alloys like brass.
- What do you think metal X could be?
- Write the name, formula and colour of salt XSO4.
- What is the blue precipitate Y?
- Write a chemical equation of the reaction which takes place when salt XSO4 reacts with sodium hydroxide solution. Give the state symbols of all the reactants and products which occur in the above equation.
Express the following facts in the form of a balanced chemical equation:
“When a strip of copper metal is placed in a solution of silver nitrate, metallic silver is precipitated and a solution containing copper nitrate is formed”.
Write word equation for the following skeletal equation:
\[\ce{AgBr -> Ag + Br2}\]
Balance the following chemical equation :
H2 + O2 → H2O
Write your observation for the following chemical reaction and name the product formed :
When manganese dioxide is added to potassium chlorate and heated.
Write your observation for the following chemical reaction and name the product formed :
When an aqueous solution of sodium chloride is mixed with an aqueous solution of silver nitrate.
Write symbolic representation for the following word equation and balance them :
Carbon + Oxygen → Carbon dioxide.
Write symbolic representation for the following word equation and balance them :
Aluminium + Chlorine → Aluminium chloride.
Balance the following equation. Also name the product formed.
`"CO" + "O"_2 → " CO"_2`
Balance the following equation. Also name the product formed.
K2O + H2O → KOH
Write the chemical equation for the following word equation and balance them.
Nitrogen + Oxygen → Nitrogen monoxide
Write the chemical equation for the following word equation and balance them.
Calcium + Nitrogen → Calcium nitride
Balance the following equation:
Pb3O4 → PbO + O2
Write the balanced chemical equation of the following reaction.
zinc sulphide + oxygen → zinc oxide + sulphur dioxide
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate moles of chlorine gas formed.
Match column A with column B.
| Column A | Column B |
| (a) Blue salt changes to white and then black | (i) Ammonium dichromate |
| (b) Orange coloured compound changes to green. | (ii) Iodine |
| (c) Red compound changes to brown and then yellow. | (iii) Zinc Nitrate |
| (d) White to yellow when hot and white when cold. | (iv) Copper sulphate |
| (e) Violet solid changes to violet vapours. | (v) Red Lead |
Grills of doors and windows are always painted before they are used.
Write word equation for the following molecular equation:
\[\ce{CaCO3 + 2HCl ->[\triangle] CaCl2 + H2O + CO2 [g]}\]
Word equation:
State which characteristic does [g] in the above reaction indicate. The word equation of:
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.
Give a balanced equation for addition of iron to copper [II] sulphate solution. State the change in colour seen.
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:
Lead nitrate to ammonium hydroxide.?
Give an example of a chemical equation in which two reactants form:
four product
Balance the following simple equation:
K + H2O → KOH + H2
Write a balanced equation for the following word equation:
Aluminium + Oxygen → Aluminium oxide
With reference to a chemical equation state which of the statements 1 to 5 pertain to A or B.
A: Information provided by a chemical equation.
B: Limitations of a chemical equation.
- The nature of the individual elements.
- The speed of the reaction.
- The state of matter in which the substance is present.
- The completion of the reaction.
- The direction of the reaction.
Write an Explanation.
Balanced equations
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Make a list of the elements in the chemical equation.
