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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
What is a balanced chemical equation? Why should a chemical equation be balanced?
State whether the following statement is true or false:
A chemical equation can be balanced easily by altering the formula of a reactant or product.
Translate the following statement into chemical equation and then balance the equation:
Aluminium metal replaces iron from ferric oxide, Fe2O3, giving aluminium oxide and iron.
Write complete balanced equation for the following reaction:
Calcium (solid) + water (liquid) 
Calcium Hydroxide (solution) + Hydrogen (gas)
Balance the given equation:
Mg(OH)2 + HCI MgCI + H2O
Balance the given chemical equation:
NH3 → N2 + H2
Convey the following information in the form of a balanced chemical equation:
"An aqueous solution of ferrous sulphate reacts with an aqueous solution of sodium hydroxide to form a precipitate of ferrous hydroxide and sodium sulphate remains in solution."
Is Respiration an endothermic reaction or an exothermic reaction?
When metal X is treated with a dilute acid Y, then a gas Z is evolved which burns readily by making a little explosion.
(a) Name any two metals which can behave like metal X.
(b) Name any two acids which can behave like acid Y.
(c) Name the gas Z.
(d) Is the gas Z lighter than or heavier than air?
(e) Is the reaction between metal X and dilute acid Y, exothermic or endothermic?
(f) 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.
The metal M reacts vigorously with water to form a solution S and a gas G. The solution S turns red litmus to blue whereas gas G, which is lighter than air, burns with a pop sound. Metal M has a low melting point and it is used as a coolant in nuclear reactors.
(a) What is metal M?
(b) What is solution S? Is it acidic or alkaline?
(c) What is gas G?
(d) Write a balanced chemical equation for the reaction which takes place when metal M reacts with water.
(e) Is this reaction exothermic or endothermic?
A white precipitate can be obtained by adding dilute sulphuric acid to:
(a) CuSO4 solution
(b) Nacl solution
(c) BaCl2 solution
(d) Na2SO4 solution
Write the balanced equation for the following chemical reaction.
\[\ce{Barium chloride + Aluminium sulphate -> Barium sulphate + Aluminium chloride}\]
Write word equation for the following skeletal equation:
\[\ce{KClO3 -> KCl + O2}\]
Balance the following chemical equation :
H2 + O2 → H2O
Write your observation for the following chemical reaction and name the product formed :
When ammonium chloride is heated with sodium hydroxide.
Balance the following equation Also name the product formed.
`"K" + "CI"_2 → "KCI"`
Balance the following equation. Also name the product formed.
PbCO3 → PbO +CO2
Write your observation and name the product when ron nails are added to an aqueous solution of copper sulphate.
Write the chemical equation for the following word equation and balance them.
Calcium oxide + Carbon dioxide → Calcium carbonate
Balance the following equation:
Fe + H2O → Fe3O4 + H2
Balance the following equation:
Ca + N2 → Ca3N2
Balance the following equation:
NaHCO3 → Na2CO3 + H2O + CO2
Choose the correct answer from the options given below.
The formula of sodium carbonate is Na2CO3 and that of calcium hydrogen carbonate is
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate mass of MnO2 used.
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate moles of salt formed.
Choose the correct alternative and rewrite the following sentence.
Which of the following is not required to find the pH of a given solution?
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.
Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.
Electrical energy
Name the following:
Two non-metal which react explosively when brought in close contact.
Balance the following simple equation:
Fe + H2O ⇌ Fe3O4 + H2
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.
Give a balanced equation by the partial equation method, [steps are given below].
Oxidation of Lead [II] Sulphide by Ozone
- Ozone first decomposes to give molecular oxygen & nascent oxygen.
- Nascent oxygen then oxidises lead [II] sulphide to lead [II] sulphate.
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
C2H5OH + 3O2 → 2CO2 + 2H2O
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Balance the equation with proper coefficient and rewrite the equation.
Which of the following is not a physical change?
Which of the following statements about the given reaction are correct?
`3"Fe"("s") + 4"H"_2"O"("g") -> "Fe"_3"O"_4("s") + 4"H"_2("g")`
- Iron metal is getting oxidised
- Water is getting reduced
- Water is acting as reducing agent
- Water is acting as oxidising agent
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?
Which of the following is the correct observation of the reaction shown in the above set up?
