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प्रश्न
The chemical reactions in which heat is liberated are called endothermic reactions.
विकल्प
True
False
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उत्तर
The chemical reactions in which heat is liberated are called endothermic reactions. - False
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संबंधित प्रश्न
What does the symbol (aq) represent in a chemical equation?
Write complete balanced equation for the following reaction:
Calcium (solid) + water (liquid) 
Calcium Hydroxide (solution) + Hydrogen (gas)
Balance the given equation:
Fe + O2 
Fe2O3
Balance the given equation:
NH3 + CuO 
Cu +N2 +H2O
Giving examples, state the difference between balanced and unbalanced chemical equations.
Balance the given chemical equation:
C + CO2 → CO
When hydrogen is passed over copper oxide, copper and steam are formed. Write a balanced equation for this reaction and state which of the chemicals are elements.
When hydrogen is passed over copper oxide, copper and steam are formed. Write a balanced equation for this reaction and state which of the chemicals are reactants.
With the help of an appropriate example, justify that some of the chemical reactions are determined by Evolution of a gas.
Give chemical equation for the reaction involved in the above case.
With the help of an appropriate example, justify that some of the chemical reactions are determined by Change in temperature.
Give chemical equation for the reaction involved in the above case.
State one characteristic of the chemical reaction which takes place when wax is burned in the form of a candle?
Is Burning of natural gas an endothermic reaction or an exothermic reaction?
Write your observations and name the product when
Iron nails are added to an aqueous solution of copper sulphate.
Write word equation for the following skeletal equation:
\[\ce{Zn + HCl -> ZnCl2 + H2}\]
Balance the following chemical equation :
Na2CO3 + HCl → NaCI + H2O + CO2
Write symbolic representation for the following word equation and balance them :
Iron + Sulphur → Iron sulphide.
Balance the following equation Also name the product formed.
`"K" + "CI"_2 → "KCI"`
Balance the following equation. Also name the products formed.
`"Mg" + "O"_2 → "MgO"`
Balance the following equation. Also name the product formed.
`"KCIO"_3 → "KCI" +"O"_2`
Write the chemical equation for the following word equation and balance them.
Carbon + Oxygen → Carbon dioxide
Balance the following equation:
P + HNO3 → NO2 + H2O + H3PO4
Write the balanced chemical equation of the following reaction.
ammonia + oxygen → nitric oxide + water
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate the mass of acid required.
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 |
Define: Endothermic reaction
1 g of copper powder was taken in a China dish and heated. What change takes place on heating? When hydrogen gas is passed over this heated substance, a visible change is seen in it. Give the chemical equations of reactions, the name and the color of the products formed in each case.
When a potassium iodide solution is added to a solution of lead (II) nitrate in a test tube, a precipitate is formed.
What is the colour of this precipitate? Name the compound precipitated.
Write word equation for the following molecular equation:
\[\ce{NH3 [g] + HCl [g] ⇌ NH4Cl [s]}\]
Word equation:
State which characteristic is observed in the above reaction.
Give an-example of a similar above characteristic, seen between two other gaseous reactants.
In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.
NH3 + HCl ⇌ NH4Cl
Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.
Catalyst
An element X is trivalent. Write the balanced equation for the combustion of X in oxygen.
Fill in the blank with the correct word from the options given below:
A chemical equation is a shorthand form for a _______ change.
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
Cl2 + 2H2O + SO2 → 4HCl + H2SO4
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
PbO2 +4HCl → PbCl2 + H2O + Cl2
In the chemical equation the _______ are written on the left-hand side.
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?
Complete the following blank in the equation as indicated.
\[\ce{CaH2_{(s)} + 2H2O_{( aq)}-> Ca(OH)2_{(s)} + 2H2_{(g)}}\]
Molecules: 6.02 × 1023 + ______ `→` ______ + ______
