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प्रश्न
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 – zinc carbonate.
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उत्तर
Change of colour — In certain chemical reactions a change of colour is seen to be observed. Heat on substances to observe change in colour of reactants and products.
Heat on:
Zinc carbonate ZnCO3 → ZnO + CO2 [g]
Colour change:
Zinc carbonate [ZnCO3] – White – to Zinc oxide [ZnO] – Yellow (when hot)
APPEARS IN
संबंधित प्रश्न
Complete and balance the following equation:
NaOH + .......... \[\ce{-> Na2SO4 + H2O}\]
Balance the following equation and add state symbols:
\[\ce{Zn + HCl -> ZnCl2 + H2}\]
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Give a chemical equation for the reaction involved in the above case.
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Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2 ↑
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Zn + KOH → K2ZnO2 + H2
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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.
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four product
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
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Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Make a list of the elements in the chemical equation.
