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प्रश्न
Give one example of a chemical reaction characterised by a change in state.
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उत्तर
The combustion reaction of candle wax (solid) initially produces molten wax (liquid), then carbon dioxide (gas) and water vapour (liquid). So, in this reaction, the state of matter changes from solid to liquid and gas.
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संबंधित प्रश्न
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.
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 non-metals.
Give one example of a chemical reaction characterised by the formation of a precipitate.
Balance the following chemical equation:
A white precipitate can be obtained by adding dilute sulphuric acid to:
(a) CuSO4 solution
(b) Nacl solution
(c) BaCl2 solution
(d) Na2SO4 solution
Balance the following equation. Also name the product formed.
`"NaNO"_3 → "NaNO"_2 + "O"_2` Name of product (s)
To determine the percentage of water absorbed by raisins, raisins are soaked in water for:
Raisins are wiped off gently before final weighing with the help of
Balance the equation stepwise.
SO2(g) + H2S(aq) → S(s) + H2O(l)
Balance the following equation:
Pb3O4 → PbO + O2
Balance the following equation:
S + H2SO4 → SO2 + H2O
Balance the following equation:
Zn + HNO3 `→` Zn(NO3)2 + H2O + NO2
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate the volume of chlorine gas formed at S.T.P.
How is a flame test performed?
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.
Representation of the results of a chemical change – is a chemical equation.
For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓
Answer the following:
Write the word equation for the above molecular equation.
Name the following:
Two non-metal which react explosively when brought in close contact.
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↓
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
State why the compound MnO2 is written above the arrow.
Balance the following simple equation:
FeCl2 + Cl2 → FeCl3
