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प्रश्न
The chemical reactions in which heat is liberated are called endothermic reactions.
पर्याय
True
False
उत्तर
The chemical reactions in which heat is liberated are called endothermic reactions. - False
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संबंधित प्रश्न
On what basis is a chemical equation balanced?
Translate the following statement into chemical equation and then balance the equation:
Barium chloride reacts with zinc sulphate to give zinc chloride and barium sulphate.
Correct and balance the following equation:
N + H 
NH3
Balance the given equation:
BaCI2 + H2SO4 
BaSO4 + HCI
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.
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 products.
Write the balanced equation for the following reaction, and add the state symbols:
Sodium hydroxide reacts with sulphuric acid to produce sodium sulphate and water.
Give one example of a chemical reaction characterised by change in state.
State the various characteristics of chemical reactions.
An acid which can decolourise purple coloured potassium permanganate solution is:
(a) sulphuric acid
(b) citric acid
(c) carbonic acid
(d) hydrochloric acid
When water is added gradually to a white solid X, a hissing sound is heard and a lot of heat is produced forming a product Y. A suspension of Y in water is applied to the walls of a house during white washing. A clear solution of Y is also used for testing carbon dioxide gas in the laboratory.
(a) What could be solid X? Write its chemical formula.
(b) What could be product Y? Write its chemical formula.
(c) What is the common name of the solution of Y which is used for testing carbon dioxide gas?
(d) Write chemical equation of the reaction which takes place on adding water to slid X.
(e) Which characteristic of chemical reactions is illustrated by this example?
Name the type of chemical reaction shown by the following equation:
2Mg+ O2 → 2MgO
Balance the following chemical equation :
Na20 + H20 → NaOH
To determine the percentage of water absorbed by raisins, raisins are soaked in water for:
Show the formation of Na2O by the transfer of electrons.
State the information conveyed by the following equation:
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2 ↑
Balance the following equation:
Zn + HNO3 `→` Zn(NO3)2 + H2O + NO2
Write the balanced chemical equation of the following reaction.
ammonia + oxygen → nitric oxide + water
Write the balanced chemical equation of the following reaction.
sodium chloride + manganese dioxide + sulphuric acid → sodium hydrogen sulphate + manganese sulphate + water + chlorine.
Define: Endothermic reaction
Answer the following question:
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.
Write word equation for the following molecular equation:
CuCo3 → CuO + CO2 [g]
Word equation:
State the characteristics or indications occurring in the above reaction.
Write word equation for the following molecular equation:
AgN03 + HCI → HNO3 + AgCl ↓
Word equation:
State whether AgCl is soluble or insoluble in HN03.
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.
Representation of the results of a chemical change – is a chemical equation.
For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓
Answer the following:
What is the indications of the arrow between the reactants and the products and of the arrow pointing downwards at the end.
Write word equation for the following chemical reaction given below. Also state the observation seen in the case.
\[\ce{Na2SO3 + 2HCl ->[\triangle] 2NaCl + H2O + SO2}\]
Write word equation for the following chemical reaction given below. Also state the observation seen in the case.
Pb(NO3)2 + 2NH4OH → 2NH4N03 + Pb(OH)2↓
Write word equation for the following chemical reaction given below. Also state the observation seen in the case.
\[\ce{2SO2 + O2 ⇌[V2O5][450°C] 2SO3}\]
Give an example of a chemical equation in which two reactants form:
four product
Balance the following simple equation:
Al + H2O → Al2O3 + H2
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
3CuO + NH3 → 3Cu + 3H2O + N2
Complete the given chemical reaction.
\[\ce{CuSO_{4(aq)} + Fe_{(s)} ->}\]______ + ______
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.
What is a chemical equation?
Write the skeleton equation for the following word equation and then balance them.
- Carbon + Oxygen → Carbon dioxide.
- Phosphorus + Chlorine → Phosphorus pentachloride.
- Sulphur + Oxygen → Sulphur dioxide.
- Magnesium + hydrogen → Magnesium + Hydrogen chloride chloride.
What are the steps involved in writing the skeletal equation?
Dil. HCl is added to Zn granules. How will you prove that chemical change has taken place here? Support your response with two arguments.
