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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
Translate the following statement into chemical equation and then balance it.
Hydrogen gas combines with nitrogen to form ammonia
Translate the following statement into chemical equation and then balance it.
Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.
Balance the given equation:
HNO3 + Ca(OH)2 
Ca(NO3)2 + H2O
Fill in the following blank with suitable word:
Chemical equations are balanced to satisfy the law of ............
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 compounds.
Write balanced chemical equation from the following information:
An aqueous calcium hydroxide solution (lime water) reacts with carbon dioxide gas to produce a solid calcium carbonate precipitate and water.
Balance the following chemical equation:
MnO2 + HCI → MnCI2 + CI2 + H2O
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?
Balance the following chemical equation:
The removal of oxygen from a substance is called:
(a) oxidation
(b) corrosion
(c) reduction
(d) rancidity
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 and name the product when zinc reacts with dilute hydrochloric acid.
Write your observation and name the product when ron nails are added to an aqueous solution of copper sulphate.
Raisins are wiped off gently before final weighing with the help of
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:
S + H2SO4 → SO2 + H2O
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
Write the balanced chemical equation of the following reaction.
ammonia + oxygen → nitric oxide + water
Write the balanced chemical equation of the following reaction.
barium chloride + sulphuric acid → barium sulphate + hydrochloric acid
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
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 chlorine gas 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?
Name the substances that are getting oxidised and reduced in the process.
Write word equation for the following molecular equation:
Na2SO3 + 2HCl [dil.] → 2NaCl + H2O + SO2 [g]
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:
Dilute hydrochloric acid to silver nitrate.
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.
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.?
Representation of the results of a chemical change – is a chemical equation.
For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓
Answer the following:
Is the equation given above a balanced equation. Give reasons.
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.
Name the following:
A catalyst which increases the rate of a chemical reaction.
Write word equation for the following chemical reaction given below. Also state the observation seen in the case.
\[\ce{ZnCo3->[\triangle] ZnO + CO2}\]
Balance the following simple equation:
FeCl2 + Cl2 → FeCl3
Balance the following simple equation:
K + H2O → KOH + H2
Write three steps of writing chemical equations with example?
Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is(are) correct?
- In beakers A and B, exothermic process has occurred.
- In beakers A and B, endothermic process has occurred.
- In beaker C exothermic process has occurred.
- In beaker C endothermic process has occurred.
