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प्रश्न
A chemical equation is a statement that describes a chemical change in terms of
पर्याय
symbols and formulae
energy
number of atoms
colours
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उत्तर
symbols and formulae.
APPEARS IN
संबंधित प्रश्न
Name three biochemical catalysts found in the human body.
Complete and balance the following chemical equations
Na + H2 O →
Write the missing reactants and products and balance the equations.
NaOH + ............... `→` NaCI + ...................
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Miscible liquids having slightly different boiling points can be separated by the
- evaporation
- distillation
- fractional distillation
- sedimentation
What are homogenous reactions ?
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)
A colourless solution of calcium hydroxide in a test tube turns ______ on blowing in it through a blow tube for some time.
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)
Oxygen is a ______ in respiration.
When hydrogen burns in oxygen, water is formed; when electricity is passed through water, hydrogen and oxygen are given out. Name the type of chemical change involved in the two cases.
State the original colour of the following substance and colour of residue obtained after heating.
Copper 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.
Select the correct answer for the following options:
The pale blue precipitated obtained when copper [II] sulphate reacts with sodium hydroxide.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
A coloured substance which leaves on strong heating a black residue and evolves two colourless gases one of which is acidic and the other neutral.
State the following reaction represent oxidation or reduction.
\[\ce{Fe++->Fe+++}\]
A chemical reaction is often accompanied by external indications or characteristics.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Calcium hydroxide.
When an aqueous solution of potassium chloride is added to an aqueous solution of silver nitrate, a white precipitate is formed. Give the chemical equation of this reaction.
Two chemical species X and Y combine together to form a product P which contains both X and Y
\[\ce{X + Y -> P}\]
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y and P are correct?
(i) P is a compound
(ii) X and Y are compounds
(iii) X and Y are elements
(iv) P has a fixed composition
Beating an egg to make a cake is a ______.
Galvanization is a process in which ______ is coated as a layer of iron.
Write five changes in the characteristics of a substance that can take place during a chemical change.
