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A compound which is prepared from gypsum has the property of hardening when mixed with a proper quantity of water
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|
1
|
732
|
March 29, 2019
|
|
Fresh milk has a pH of 6. When it changes into curd (yogurt) will its pH value increase or decrease? why?
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|
1
|
2093
|
March 29, 2019
|
|
Give two uses of baking soda and washing soda each
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1
|
756
|
March 29, 2019
|
|
A compound ‘A’ on heating at 370K gives ‘B’, used as plaster for supporting fractured bones in the right position
|
|
1
|
6579
|
March 29, 2019
|
|
Dry ammonia has no action on litmus paper but a solution of ammonia in water turns red litmus paper blue. Why is it so?
|
|
1
|
749
|
March 29, 2019
|
|
Write the chemical-formula for washing soda. How may it be obtained from baking soda? Name an industrial use of washing soda other than washing clothes?
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|
1
|
6397
|
March 29, 2019
|
|
How does the flow of acid rain water into a river make the survival of aquatic life in the river difficult?
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1
|
794
|
March 29, 2019
|
|
(a) Give Arrhenius definition of an acid and a base
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|
1
|
4521
|
March 29, 2019
|
|
Why should water be never added dropwise to concentrated sulphuric acid?
|
|
1
|
3406
|
March 29, 2019
|
|
Given below are the pH values of four different liquids: 7.0, 14.0, 4.0, 2.0, which of these could be that of:
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|
1
|
4986
|
March 29, 2019
|
|
What happens when crystals of washing soda are left open in dry air? What is this change named as? Name two industries based on use of washing soda?
|
|
1
|
1410
|
March 29, 2019
|
|
How is plaster of paris chemically different from gypsum? How may they be interconverted? Write one use of plaster of paris
|
|
1
|
8448
|
March 29, 2019
|
|
How will you test a gas which is liberated when hydrochloric acid reacts with an active metal?
|
|
1
|
3075
|
March 29, 2019
|
|
Write chemical equations to show the reactions taking place when a glass rod dipped in concentrated hydrochloric acid is introduced in a jar containing ammonia gas?
|
|
1
|
2538
|
March 29, 2019
|
|
Write balanced chemical equation for the reactions taking place when dry blue ciystals of copper sulphate are dropped into concentrated sulphuric acid
|
|
1
|
3898
|
March 29, 2019
|
|
Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and third is a sugar solution
|
|
0
|
12857
|
March 23, 2018
|
|
Give two uses of the following acids. Nitric acid Hydrochloric acid Sulphuric acid
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|
0
|
708
|
March 23, 2018
|
|
Explain two neutralisation reactions related to daily life situation
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|
0
|
8246
|
March 23, 2018
|
|
Paheli observed that most of the fish in the pond of her village were gradually dying
|
|
0
|
6061
|
March 23, 2018
|
|
You are provided with three test tubes A, B and C as shown in figure with different liquids
|
|
0
|
2751
|
March 23, 2018
|
|
You are provided with four test tubes containing sugar solution, baking soda solution, tamarind solution, salt solution
|
|
0
|
2839
|
March 23, 2018
|
|
A farmer was unhappy because of his low crop yield
|
|
0
|
8496
|
March 23, 2018
|
|
Boojho, Paheli and their friend Golu were provided with a test tube each containing China rose solution which was pink in colour
|
|
0
|
1759
|
March 23, 2018
|
|
Why is carbonic acid added to soft drinks?
|
|
0
|
2925
|
March 23, 2018
|
|
Write two uses of the following. Calcium hydroxide Sodium hydroxide
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|
0
|
907
|
March 23, 2018
|
|
Describe the process of neutralisation with the help of an example
|
|
0
|
9128
|
March 23, 2018
|
|
List three properties of acids bases
|
|
0
|
651
|
March 23, 2018
|
|
Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution?
|
|
0
|
1195
|
March 23, 2018
|
|
Explain why an antacid tablet is taken when you suffer from acidity. calamine solution is applied on the skin when an ant bites. factory waste is neutralised before disposing it into the water bodies
|
|
0
|
1534
|
March 23, 2018
|
|
State differences between acids and bases
|
|
0
|
1027
|
March 23, 2018
|