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प्रश्न
A solution of a substance ‘X’ is used for white washing Name the substance ‘X’ and write its formula.
उत्तर
Calcium oxide CaO
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संबंधित प्रश्न
How would you show that setting of curd is a chemical change?
How do the following help in bringing about a chemical change?
pressure.
How do the following help in bringing about a chemical change?
heat.
Complete and balance the following chemical equations
NaCI + `AgNO_3` `→`
What do you observe when Iron nail is kept in copper sulphate solution for sometime.
Explain the following reaction with one suitable example of Decomposition 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)
An ______ is drawn in between the reactants and products while writing the equation for a chemical reaction.
Explain by writing a word equation.
Hard water gets softened on mixing with a solution of washing soda.
Choose the correct option from the bracket and explain the statement giving a reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
Addition of an aqueous solution of ZnSO4 to an aqueous solution of BaCl2 is an example of ______ reaction.
Give an example of a reaction where the following are involved:
Solution
Define Electrochemical reaction
Give an example
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Pb(NO3)2 + KI →
Complete the following table and write your observations.
|
Hydrogen sulphide |
Ammonia |
Sulphur dioxide |
Hydrogen chloride |
|
|
Shake the gas with red litmus solution |
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Shake the gas with blue litmus solution |
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|
Apply a burning splint to a gas |
Give a chemical test to distinguish between the following gases.
HCl and H2S
Give a chemical test to distinguish between the following gases.
NH3 and HCl
Write your observation and a balanced equation in the case of the following substances being heated.
Copper carbonate.
Write your observation and a balanced equation in the case of the following substances being heated.
Ammonium chloride
Give a word equation for the following reaction.
A compound which on heating shows – colour change from brown to yellow.
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 white solid which evolves two colourless gases which on cooling combine and condense on the cooler parts of the test tube.
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper carbonate to copper oxide
Explain the Silver nitrate solution is kept in coloured reagent bottles in the laboratory.
State the following reaction represent oxidation or reduction.
\[\ce{Cu++->Cu}\]
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].
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True or False. If false, give the correct answer.
Taking a glass of water and freezing it by placing it in the freezer is a chemical change.
Mention the various conditions required for a chemical reaction to occur.
Match the following:
| 1. | Sodium Chloride | a. | CaSO41/2H2O |
| 2. | Calcium sulphate dihydrate | b. | C2H5Oh |
| 3. | Magnesium sulphate hydrate | c. | CaSO4.2H2O |
| 4. | Calcium sulphate hemihydrate | d. | NaCl |
| 5. | Phenol | e. | MgSO4.H2O |
Classify the following as physical or chemical properties
Zinc dissolves in hydrochloric acid with the evolution of hydrogen gas.
The reaction of H2 gas with oxygen gas to form water is an example of ______.
