मराठी
सी.आई.एस.सी.ई.आयसीएसई ICSE Class 8

How Do the Following Help in Bringing About a Chemical Change? Light. - Chemistry

Advertisements
Advertisements

प्रश्न

How do the following help in bringing about a chemical change?

light.

एका वाक्यात उत्तर

उत्तर

Some chemical reactions can take place in the presence of light. Ex. Photosynthesis.

\[\ce{6CO2 + 6H2O⇌[sunlight][Chlorophyll]\underset{\text{glucose}}{C6H12O6 +6O2}}\]

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 6: Chemical Reactions - Exercise 1 [पृष्ठ ७३]

APPEARS IN

सेलिना Concise Chemistry [English] Class 8 ICSE
पाठ 6 Chemical Reactions
Exercise 1 | Q 3.2 | पृष्ठ ७३

संबंधित प्रश्‍न

Complete and balance the following chemical equations

NaCI + `AgNO_3`  `→`


What are homogenous reactions ?


Balance the following equation :

Fe + H2O → Fe3O4 + H2


What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.


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)

Rusting of iron is a ______ chemical change. 


Define Electrochemical reaction
Give an example 

 

 


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.


What do you understand by precipitation reaction? Explain with examples.


Name: Gas with rotten egg smell. 


Give a chemical test to distinguish between the following gases. 

CO2 and SO2


Distinguish by heating the following in dry test tubs.

Zinc nitrate and copper nitrate.


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 a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to sodium sulphite.


Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.

Ammonium dichromate.


Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.

Lead nitrate.


What kind of a change is associated with decaying of a plants?


What happens when cane sugar is strongly heated? Mention any two changes in it.


______ is not a chemical change.


A bag of cement lying in the open gets wet due to rain during the night. The next day the sun shines brightly. Do you think the changes, which have occurred in the cement, could be reversed?


Chemical change is a temporary change.


______ change results in the change of the substance.


Which of the following are chemical changes?

(i) Decaying of wood

(ii) Burning of wood

(iii) Sawing of wood

(iv) Hammering of a nail into a piece of wood


Classify the following as physical or chemical properties

Zinc dissolves in hydrochloric acid with the evolution of hydrogen gas.


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.


Which of the following is/are true when milk changes into curd?

  1. Its state is changed from liquid to semi-solid.
  2. It changes colour.
  3. It changes the taste.
  4. The change cannot be reversed.

Choose the correct option from below:


Which of the following statement is incorrect for a chemical reaction?


Collect information about the types of fuels used for cooking in your area. Discuss with your teachers/parents/others which fuels are less polluting and why.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×