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प्रश्न
What are products? Explain with the help of example.
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उत्तर
- The substances formed as a result of a chemical reaction by the formation of new bonds are called products.
- e.g. Decomposition of calcium carbonate by heating to form calcium oxide and carbon dioxide is a chemical reaction. In this reaction, calcium carbonate is the reactant while calcium oxide and carbon dioxide are the products.
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संबंधित प्रश्न
How will you indicate the following effect in a chemical equation?
Endothermic reaction
Correct and balance the following equation:
\[\ce{Ca + H2O -> CaOH + H}\]
Explain, with an example, how the physical states of the reactants and products can be shown in a chemical equation.
Potassium chlorate (KClO3) on heating forms potassium chloride and oxygen. Write a balanced equation for this reaction and indicate the evolution of gas.
With the help of an appropriate example, justify that some of the chemical reactions are determined by a change in temperature.
Give a chemical equation for the reaction involved in the above case.
State the various characteristics of chemical reactions.
What do you understand by endothermic reactions?
One of the following does not happen during a chemical reaction. This is:
Balance the following chemical equation:
\[\ce{FeSO4 ->[Heat] Fe2O3 + SO2 + SO3}\]
Write word equation for the following skeletal equation:
\[\ce{KClO3 -> KCl + O2}\]
Write word equation for the following skeletal equation:
\[\ce{Zn + HCl -> ZnCl2 + H2}\]
Balance the following equation. Also name the product formed.
` "H"_2"O"_2 → "H" _2 "O" + "O"_2`
Dry raisins were soaked in water for 2 hours, to determine the percentage of water absorbed by raisins. Before final weighing of swollen raisins, the extra water left on the surface of soaked raisins was removed by:
State the information conveyed by the following equation:
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2 ↑
Balance the following equation:
PbS + O2 → PbO + SO2
Balance the following equation:
C + H2SO4 → CO2 + H2O + SO2
Balance the following equation:
P + HNO3 → NO2 + H2O + H3PO4
Write the balanced chemical equation of the following reaction. sodium hydroxide + sulphuric acid → sodium sulphate + water
Write the balanced chemical equation of the following reaction.
silver nitrate → silver + nitrogen dioxide + oxygen
Write the balanced chemical equation of the following reaction.
aluminium sulphate + sodium hydroxide → sodium sulphate + sodium meta aluminate + water.
Complete the following blank in the equation as indicated.
\[\ce{CaH2_{(s)} + 2H2O_{( aq)}-> Ca(OH)2_{(s)} + 2H2_{(g)}}\]
Moles: 1 mole + ______ `→` ______ + ______
Match column A with column B.
| Column A | Column B |
| (a) Blue salt changes to white and then black | (i) Ammonium dichromate |
| (b) Orange coloured compound changes to green. | (ii) Iodine |
| (c) Red compound changes to brown and then yellow. | (iii) Zinc Nitrate |
| (d) White to yellow when hot and white when cold. | (iv) Copper sulphate |
| (e) Violet solid changes to violet vapours. | (v) Red Lead |
The chemical reactions in which heat is liberated are called endothermic reactions.
A student mixes sodium sulphate powder in barium chloride powder. What change would the student observe on mixing the two powders? Justify your answer and explain how he can obtain the desired change.
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.
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:
Iron [II] sulphate to sodium hydroxide.
Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.
Electrical energy
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:
three product
Balance the following simple equation:
Al + O2 → Al2O3
Balance the following simple equation:
Mg + N2 → Mg3N2
Balance the following simple equation:
H2 + O2 → H2O
Balance the following simple equation:
NaHCO3 + H2SO4 → Na2SO4 + H2O + CO2
Give a balanced equation by the partial equation method, [steps are given below].
Oxidation of Lead [II] Sulphide by Ozone
- Ozone first decomposes to give molecular oxygen & nascent oxygen.
- Nascent oxygen then oxidises lead [II] sulphide to lead [II] sulphate.
Match the columns.
| Reactants | Products | Types of chemical reaction | ||
| 1. | MgH2 | → | Mg + H2 | Endothermic |
| 2. | 2H2S + SO2 | → | 3S + 2H2O | Oxidation |
| 3. | CaO + H2O | → | Ca(OH)2 + heat | Exothermic |
| Redox | ||||
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Write the number of atoms of reactants and products.
Balance the following chemical equation.
- Na + O2 → Na2O3
- Ca + N2 → Ca3N2
- N2 + H2 →NH3
- CaCO3 +HCl → CaCl2 + CO2 +H2O
- Pb(NO3)2 → PbO + NO2 + O2
What is called thermolysis reactions?
