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प्रश्न
Balancing a chemical equation is based on
विकल्प
Law of conservation of mass
Mass of reactants and products
Symbols and formulae
None of the above
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उत्तर
Law of conservation of mass.
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संबंधित प्रश्न
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Formation of manure from leaves is a physical change.
Name three reducing agents ?
Is kerosene an electrolyte or a non-electrolyte ?
Define chemical reaction.
Write true or false.
A chemical equation gives only qualitative information of a chemical reaction.
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
The spoiling of food is a chemical change which is recognized from the generation of certain ______ due to it.
Explain by writing a word equation.
Bubbles are seen on adding lemon juice to baking soda.
Complete and balance the following reaction:
\[\ce{CuCO3 ->[\Delta]}\]
Name: Two carbonates do not produce carbon dioxide on heating.
Write your observation and a balanced equation in the case of the following substances being heated.
Zinc carbonate.
Give examples of exothermic reactions i.e. heat evolved in each of the following:
(a) reaction between a solid and a liquid
(b) reaction between two gases
Give two examples of exothermic reactions seen in everyday life.
A chemical reaction is often accompanied by external indications or characteristics which include –
- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
With reference to each of the above indications, state the external indication seen during – Addition of dilute acid to an active metal.
Give balanced equation for the following conversion affected by heat alone on the substance:
Ammonium dichromate to nitrogen
Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to sodium sulphite.
Explain with the help of balanced equations, how precipitation reactions are used for identifying the positive radicals in three different salts, each having a different cation [positive ion].
Burning of paper is a ______ change.
On heating calcium carbonate gets converted into calcium oxide and carbon dioxide.
(a) Is this a physical or a chemical change?
(b) Can you prepare one acidic and one basic solution by using the products formed in the above process? If so, write the chemical equation involved.
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
Which is used as a catalyst during the process of hydrogenation of oils?
