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प्रश्न
Why do we need to balance chemical equations?
Why do we balance a chemical equation?
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उत्तर
A chemical equation needs to be balanced so as to make the number of atoms of the reactants equal to the number of atoms of the products.
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संबंधित प्रश्न
Complete and balance the following equation:
NaOH + ............ 
Na2 SO4 + H2O
What is a chemical equation? Explain with the help of an example.
Give one example of a chemical reaction characterised by change in state.
Is Burning of natural gas an endothermic reaction or an exothermic reaction?
An acid which can decolourise purple coloured potassium permanganate solution is:
(a) sulphuric acid
(b) citric acid
(c) carbonic acid
(d) hydrochloric acid
When the solution of substance X is added to a solution of potassium iodide, then a yellow solid separates out from the solution.
(a) What do you think substance X is likely to be?
(b) Name the substance which the yellow solid consists of.
(c) Which characteristic of chemical reaction is illustrated by this example?
(d) Write a balanced chemical equation for the reaction which takes place. Mention the physical states of all the reactant 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.
(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.
Write word equation for the following skeletal equation:
\[\ce{KClO3 -> KCl + O2}\]
Write symbolic representation for the following word equation and balance them :
Iron + Sulphur → Iron sulphide.
Balance the following equation:
NO2 +H2O → HNO2 + HNO3
Balance the following equation:
Pb3O4 + HCl → PbCl2 + H2O + Cl2
Write the balanced chemical equations of the following reactions.
chlorine + sulphur dioxide + water → sulphuric acid + hydrogen chloride
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 – lead [IV] oxide.
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
State what is a ‘balanced equation’.
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
State why the compound MnO2 is written above the arrow.
Balance the following simple equation:
H2 + Cl2 → HCl
Balance the following simple equation:
KHCO3 → K2CO3 + H2O + CO2
Balance the following simple equation:
\[\ce{N2 + H2 <=> NH3}\]
Balance the following simple equation:
Fe2O3 + H2 → Fe + H2O
A student took a small amount of copper oxide in a conical flask and added dilute hydrochloric acid to it with constant stirring. He observed a change in colour of the solution.
- Write the name of the compound formed and its colour.
- Write a balanced chemical equation for the reaction involved.
