Tag: evs

Questions Related to evs

Water, ice and steam are all:

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. elements

  2. mixtures

  3. compounds

  4. none of these

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Correct Option: C
Explanation:

Compounds can exist in all three states(solid, liquid, gas) provided that they can be heated/cooled enough(to their respective boiling/melting points). Thus water, ice, and steam all are compounds of hydrogen and oxygen.

Levelling effect is mimimum in

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. Water

  2. DMSO

  3. Acetic acid

  4. Liquid ammonia

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Correct Option: A

Water is made of two elements, which are ________.

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. both solids

  2. both liquids

  3. both gases

  4. one liquid and the other a gas

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Correct Option: C
Explanation:

Water is made of Hydrogen and Oxygen, which are gases at STP. 

Dissolved salts in potable water provide only taste, but are useless for living being.

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. True

  2. False

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Correct Option: B
Explanation:

Dissolved salts in potable water provide taste and are useful for living being like calcium and magnesium ions.

_________ is celebrated as the world water day.

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. 20 March

  2. 22 March

  3. 18 March

  4. 16 March

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Correct Option: B
Explanation:

$22^{nd}$ of March every year is celebrated as the world water day.

By burning which of the following elements would you get water?

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. carbon

  2. hydrogen

  3. nitrogen

  4. None of the above

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Correct Option: B
Explanation:

Burning hydrogen with oxygen give rise to formation of water.

Which scientist showed that water is made up of hydrogen and oxygen?

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. Antonie Lavoiser

  2. Dalton

  3. Henry Cavendish

  4. Carl Scheele

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Correct Option: C
Explanation:

Henry Cavendish showed that water is made up of hydrogen and oxygen.

What is the no. of molecules of water in $CuSO _4$?

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. 3

  2. 4

  3. 5

  4. 6

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Correct Option: C
Explanation:

The number of molecules of water is 5. The formula is $CuSO _4. 5H _2O$.

What is the colour of $CuSO _4.5H _2O$?

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. Blue

  2. Black

  3. Green

  4. Brown

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Correct Option: A
Explanation:

The colour of hydrated copper sulphate is blue.

Addition of water to $CoCl _2$ changes colour from blue to:

evs water: a precious resource importance of water let's play with water water and its properties water resources and conservation

  1. red

  2. pink

  3. violet

  4. green

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Correct Option: B