What Do You Observe When : Ime is Dissolved in Water. - Chemistry

Advertisements
Advertisements
One Line Answer

What do you observe when :

ime is dissolved in water.

Advertisements

Solution

The following two observations will be observed
(i) A hissing sound is observed.
(ii) The mixture starts boiling and lime water is obtained.

  Is there an error in this question or solution?
Chapter 2: Physical and Chemical Changes - Exercise

APPEARS IN

Selina Concise Chemistry Class 7 ICSE
Chapter 2 Physical and Chemical Changes
Exercise | Q 8.8

RELATED QUESTIONS

What is the physical state of water at 0°C.


What do you mean by the change of state? Write the flow chart showing the complete cycle of change of state.


Mention a change which is always


What do you observe when :

water is boiled


State whether the following is physical or chemical changes.

heating of water —


Tick (√) the correct alternative from the choice given for the following statement.

When you put some ice cubes in a glass, droplets of water are formed on the outer wall of the glass. This explains the phenomenon of


Tick (√) the correct alternative from the choice given for the following statement.

When we add water to the following substances, which one will show a chemical change?


Tick the most appropriate answer.

Melting of ice is a


Dissolving salt in water is a reversible change.


Ripening of fruits is a desirable change.


A few substances are arranged in the increasing order of 'forces of attraction' between their particles. Which one of the following represents the correct arrangement?


The Kelvin temperature is 270 K. What is the corresponding Celsius scale temperature ?


Give the usual name for the following :

Heat required to change the state of a substance without changing the temperature.


What is the (a) common unit of temperature, and (b) SI unit of temperature ?


What is the common name of solid carbon dioxide ?


Fill in the following blank with suitable words :

Temp on Kelvin scale = Temp on Celsius scale + ........................


What are the two ways in which the physical states of matter can be changed ?


When heat is constantly supplied by a burner to boiling water, then the temperature of water  during vaporisation :


The latent heat of fusion of ice is :


Match the following:

Column A Column B
(a) Evaporation of water (i) Non-periodic change
(b) Milk turning sour (ii) Periodic change
(c) Earthquake (iii) Chemical change
(d) Change of seasons (iv) Physical change
(e) Glowing of bulb (v) Reversible change

Define the following terms: Liquefaction


Differentiate between: Gas and vapour


How does a liquid changes into its gaseous state? Explain


Name the phenomenon which causes the following changes:

Conversion of ice into water


Give two examples of the following:

Substances which do not change their states.


Think and try to find a way to demonstrate water cycle in class


Explain the term vaporization


State which of the following statement is true or false. If false write the correct statement.

Solids are highly compressible and rigid.


State which of the following statement is true or false. If false write the correct statement.

Atoms/molecules in gases move only about their own positions.


State if the following is a physical property of a substance.

Lead chloride reacts with barium sulphate to give a white precipitate of lead sulphate.


In the paragraph below, write ‘solid’, ‘liquid’ or ‘gas’ in each of the brackets depending on the substance referred to just before.

On a bright sunny day, Riya and Gargi are playing with a ball ( ) in the park. Gargi feels thirsty. So, Riya brings tender coconut water ( ) for her. At the same time, a strong breeze ( ) starts blowing and it also begins to rain ( ). They run back into the house ( ), change their clothes ( ), and then their mother gives them a cup ( ) of hot milk ( ) to drink.


Discuss.

Riya pours some water from her bottle into another bottle. Does it change the shape of the water?


Discuss.

Halima picks up a small stone from the ground and puts it in the water in a dish. Does the shape of the stone change?


Write the properties of this substance.

Water


What is it made from? Why?

A sickle to cut sugarcane.


What will happen if....? And why?

A bell is made of wood.


What will happen if....? And why?

Rubber is not fitted on a pair of tongs.


Who am I?

I have no shape whatsoever!


Who am I?

I dissolve in water, but not in kerosene.


Why does this happen?

What you see in the picture.


Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.

Are any new products formed during the above process.


Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.

Can the change be reversed or is it irreversible?


Fill in the blank with the appropriate word of the statement given below:

Change of milk of curd is a _______ change.


State whether the following statement is true or false. If false write the correct statement.

Desirable changes are meaningful, while undesirable changes are unfavourable.


State whether the following statement is true or false. If false write the correct statement.

During physical changes, the composition of the original substance is not altered, but the properties of the original substance are altered.


State whether the following statement is true or false. If false write the correct statement.

During a chemical change the composition of the original substance is not altered and the change is irreversible.


Fill in the blank with the correct word of the statement given below:

Sublimation is _______ a change of state of matter.


Fill in the blanks with the correct words of the statement given below:

During sublimation, a solid on heating turns directly into _________ and on cooling back to __________.


Matter in any state is composed of small particles – molecules, atoms, or ions. Differentiate the terms above in Italics.


Select the correct answer from A, B, C, D & E for the statement given below:

The state of matter which has ___________ least density & no free surfaces.


With reference to the liquid state of matter – answer the following

On heating, the liquid, do the particles gain or lose energy.


With reference to the liquid state of matter – answer the following

At what point will the particles become free and escape as a gas.


Complete the statement by filling the blank with the correct word given below.

Conversion of vapour [or gas] into a liquid is termed ____________.


Give the reason for the following 

Solids cannot be compressed, but gases are highly compressible.


Give the reason for the following: 

The kinetic energy of molecules of gases is very large & of solids, the least.


Give the reason for the following 

On heating a sublimable solid, the molecules break free & escape from the surface of the solid directly into vapour.


Complete the blank with reference to interconversion of matter on the basis of kinetic theory-with the word ‘increase’, ‘decreases’, ‘gain’, ‘lose’, or ‘overcome’ in the following case.

During vaporization, the liquid particles ____________ energy.


Complete the blank with reference to interconversion of matter on the basis of kinetic theory-with the word ‘increase’, ‘decreases’, ‘gain’, ‘lose’, or ‘overcome’ in the following case.

During liquefaction, the particles ________ energy.


Share
Notifications



      Forgot password?
Use app×