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प्रश्न
True or false
New substances are formed in a chemical change.
विकल्प
True
False
उत्तर
True
APPEARS IN
संबंधित प्रश्न
Define; catalyst.
Complete and balance the following chemical equations:
Fe `"SO"_4` + NaOH `→`
(aq.) (aq.)
Define catalyst.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Reduction reaction is the exact opposite of
- displacement reaction
- decomposition reaction
- oxidation reaction
- none of these
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
FILL IN THE BLANK
Positively charged ions are called ........
Define chemical reaction.
Write true or false :
When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet .
A solution of a substance ‘X’ is used for white washing Name the substance ‘X’ and write its formula.
Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
To prevent rusting, a layer of ______ metal is applied on iron sheets.
Define:
Electrochemical reaction
Give one example
Name the gases which Turn moist red litmus blue.
State the original colour of the following substance and colour of residue obtained after heating.
Copper carbonate
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.
Zinc carbonate.
Give a word equation for the following reaction.
Two gases which combine to give a solid.
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper nitrate to nitrogen dioxide
Complete the table given below.
| Addition of dil. H2SO4 to FeS | Odour of gas evolved |
State whether the following reaction is oxidation or reduction.
\[\ce{Na->Na+}\]
______ gas causes tears in our eyes while cutting onions.
Limestone contains ______ mainly.
Silver metal can displace hydrogen gas from nitric acid.
The changes in which new substance with new chemical properties are formed are ______.
______ change results in the change of the substance.
The water we drink is a combination of hydrogen and oxygen.
A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
Write a word equation for the chemical change, if any.
How would you show that the settling of curd is a chemical change?
Write the effects of chemical reactions.
