Chemistry · Science General

States of Matter

2,682 Questions

States of matter questions explore physical changes, evaporation, phase transitions, and the properties of liquids and gases. Topics cover density, cryosurgery, heavy water, and electrolytes. This foundational chemistry topic frequently appears in general science sections of SSC and railway exams.

Phase change mechanismsEvaporation and temperature effectsProperties of liquidsPhysical versus chemical changesElectrolytes and heavy water

States of Matter Questions

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

.................. water does not lather with soap

  1. Hard water

  2. Soft water

  3. Contaminated water

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hard water does not lather with but instead forms a gooey mass called scum. Hard water is formed when water percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

If a boiled and filtered hard water is added to soap and it lathers, the water is :

  1. temporary hard water

  2. permanent hard water

  3. both a and b

  4. data insufficient
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hardness of water can be of two types temporary and permanent hardness. Temporary hard water contains only bicarbonates of magnesium and calcium. It can be removed by boiling. Such water on treating with soap lathers easily.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

Types of hardness of water is :

  1. temporary and semi-permanent

  2. permanent and temporary

  3. permanent and partially permanent

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hardness of water can be of two types temporary and permanent hardness. Temporary hard water contains only bicarbonates of magnesium and calcium. It can be removed by boiling. Permanent hard water contains chlorides and sulfates of calcium and magnesium. It can be removed by adding washing soda.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

The given sample of lathers easily with water, it is :

  1. hard water.

  2. soft water.

  3. permanent hard water.

  4. temporary hard water.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Soft water is surface water that contains low concentrations of ions and in particular is low in ions of calcium and magnesium. Because soft water has few calcium ions, there is no inhibition of the action of soaps and no soap scum is formed in normal washing. It lathers easily with water. Similarly, soft water produces no calcium deposits in water heating systems.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

A cloudy or milky appearance characterizes :

  1. soft water

  2. hard water

  3. chlorinated water

  4. both a and c
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

An easy way in which water manifests its hardness is scaling i.e. forming deposits through calcification that clog plumbing. These scales are usually white because calcium and magnesium are the most common sources of hardness in water. In swimming pools, a cloudy or milky appearance characterizes hard water.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

Hard water can be softened in ?

  1. A chromatograph

  2. An ion exchanger

  3. A calorimeter

  4. An earthenware pot
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Answer:- (B) An ion exchanger

Explanation:-
In ion exchanger, the hard water is softened because it no longer contains calcium or magnesium ions. Ion exchange units that replaces calcium and magnesium ions from water are known as water softeners.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks
Water which doesn't give lather immediately with soap is called soft water.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Soaps are basically sodium salt of fatty acids. 

In the presence of excess calcium and magnesium ions in water, the sodium ions are replaced by these ions and are precipitated as scum. 

Water containing an excess of these (calcium and magnesium) ions is called hard water.

Therefore option $B$ is correct.
Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

Temporary hardness can be removed by:

  1. boiling

  2. clark's process

  3. calgon's process

  4. permutit method
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

By boiling : - On boiling, soluble $Mg{ \left( HC{ O } _{ 3 } \right)  } _{ 2 }$ is converted to insoluble $Mg{ \left( OH \right)  } _{ 2 }$ and $Ca{ \left( H{ CO } _{ 3 } \right)  } _{ 2 }$ to insoluble ${ CaCO } _{ 3 }$. It is because high solubility of $Mg{ \left( OH \right)  } _{ 2 }$ as compared to $Mg{ CO } _{ 3 }$, than $Mg{ \left( OH \right)  } _{ 2 }$ is precipitated. Precipitates can be removed by filtration.


By Clark's Method : Calculated amount of lime is added to hard water $\rightarrow Ca{ CO } _{ 3 }$ precipitates out & $Mg{ \left( OH \right)  } _{ 2 }$ can be filtered off.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

Water is liquid at room temperature, the most important reason for this is the :

  1. high boiling point of water

  2. high melting point of water

  3. high heat of vapourization of water

  4. cohesive forces due to hydrogen bonds in water
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Water is liquid at room temperature, the most important reason for this is the cohesive forces due to hydrogen bonds in water.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

Which of the following is true?

  1. Vegetable oil is heavier than water

  2. Ghee is soluble in water

  3. Curd is soluble in water

  4. A person who can not swim will not drown in dead sea
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The salt is all dissolved in the water, this makes all of the water much denser than normal water, making it uncomfortable to swim in. Furthermore it means that the water is denser than the human body which is 70%, unsalted water. Meaning it is impossible to sink in the Dead Sea.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

Heavy water is:

  1. compound of deutrium and oxygen
  2. water at $4 ^\circ C$

  3. water, in which soap does not lather

  4. compound of heavy oxygen and heavy hydrogen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Heavy water is water that contains heavy hydrogen or deuterium. Deuterium differs from the hydrogen usually found in water, protium, in that each atom of deuterium contains a proton and a neutron. Heavy water may be deuterium oxide,$D _2O$ or it may be deuterium protium oxide, $DHO$. Heavy water occurs naturally, although it is much less common than regular water.