States of Water

Q.

Why does steam cause more serious burns than water at 100^oC?

Q. name the 3 states of water

Q.

What happens to intermolecular forces when a liquid turns to a gas?

Q. Why does oil never mix with water and always floats on top?

Q.

When a solid is heated, its particles vibrate more vigorously?

1. True
2. False

Q.

The gaseous form of water is present as:

1. Moisture
2. Vapour
3. Ice
4. Drinking water

Q.

Does any metal float?

Q.

Ice, water and steam have different physical states but are chemically______.

Q.

What happens when rain falls on soil without vegetational cover?

1. Rainwater percolates in soil efficiently

2. Rainwater causes loss of surface soil

3. Rainwater leads to the fertility of the soil

4. Rainwater does not cause any change in soil

Q.

The process due to which a solid changes into liquid state on the absorption of the heat energy is called:

1. Melting

2. Fusion

3. Liquation

4. Either (A) or (B)

Q.

Name two metals that possess low density.

Q.

Ice, Water and Water vapor look different and display different _______ properties but they are _______ the same.

Q. Why can't we see the evaporation of water?

Q. When hydrogen combine with oxygen what it is form ? Water pr anythink else

Q. Water exists in all the states. Discuss.

Q.

factors affecting freezing point

Q. Name a substance that you can use to keep the air dry in a closed space.

Q.

Evaporation of water becomes rapid if humidity in air is __________________.

Q.

Name two naturally occurring gaseous forms of water.

Q.

Classify these changes into reversible and irreversible. [5 MARKS]

$\begin{array}{cc}\text{S.No}& \text{Changes}\\ 1& \text{Dissolving salt in water}\\ 2& \text{Melting ice cubes}\\ 3& \text{Release of steam from pressure cooker}\\ 4& \text{Ripening of fruits}\\ 5& \text{Freezing orange juice by cooling}\end{array}$

Q.

Water exists in ........... state(s).

1. one
2. three
3. two
4. four

Q.

Steam is known to produce more severe burns than boiling water at the same temperature Explain why.

Q.

Question 17

Why is soil erosion relatively less in dense forests as compared to barren, open fields?

Q. $I$. Melting is an exothermic process.
$II$. Heat energy will cause covalent bonds in water to break as water converts from the solid state to the liquid state.

1. Statement $I$ is false, Statement $II$ is true
2. Statement $I$ is true, Statement $II$ is true
3. Statement $I$ is true, Statement $II$ is false
4. Statement $I$ is false, Statement $II$ is false

Q.

Give reasons for the following:

Doctor advise to put strips of wet cloth on the forehead of a person having high fever.

Q. What are the different states of matter in which water exists? Discuss.

Q. Why are ice, liquid water and steam consider to have the same chemical substance?

Q. Hydrogen combines with oxygen to form water. Water exists in:

1. liquid
2. gas
3. plasma
4. solid

Q. Statement 1: Ice is less dense than liquid water.
Statement 2: Water molecules are nonpolar.

1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

2. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1.

3. Statement 1 is correct but Statement 2 is not correct.

4. Statement 1 is not correct but Statement 2 is correct.

5. Both the Statement 1 and Statement 2 are not correct.

   
   

Q.

Write any two methods by which water can be conserved.