Tag: phenomena around us

Quizzes (2) Questions (57)

Questions Related to phenomena around us

Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

What property stays the same during physical and chemical changes?

  1. Density

  2. Shape

  3. Mass

  4. Arrangement of particle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Since the law of conservation of mass is valid under all circumstances, hence, mass always remains the same, whether a substance undergoes physical change or chemical change. 

Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

Which of the following is an example of chemical change?

  1. Filling up a balloon with hot air.

  2. Taking a glass of water and freezing it by placing it in the freezer.

  3. A plant collecting sunlight and turning it into food.

  4. Your dog ripping up your homework.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A plant collecting sunlight and turning it into food is a photosynthesis reaction which is an example of a photochemical reaction. This is a chemical change. 

Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

What characteristic best describes what happen during a physical change?

  1. Composition changes.

  2. Composition stays the same.

  3. Form stays the same.

  4. Mass is lost.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. 
Physical changes occur when objects or substances undergo a change that does not change their chemical composition.
Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

Common chemical changes are :

  1. change in temperature

  2. formation of precipitate

  3. formation of bubbles

  4. all of above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A change in temperature is characteristic of a chemical change. When the reactants are mixed, the temperature change caused by the reaction is an indicator of a chemical change. 


The formation of a precipitate may be one of the most common signs of a chemical reaction taking place. The formation of bubbles, or rather a gas, is another indicator of a chemical reaction taking place. When bubbles form, a temperature change could also be taking place.

So, the correct option is $D$

Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

Heating of ammonium chloride solution is a:

  1. physical change

  2. chemical change

  3. depends on temperature

  4. can't say
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

Solid ammonium chloride vapourizes to form gaseous ammonium chloride. This is a physical change. Ammonium chloride is partially dissociated. This a chemical change. The products ammonia and chlorine recombine to form ammonium chloride. This is also a chemical change.

Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

Burning of candle is a :

  1. physical change

  2. chemical change

  3. both a and b

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

On burning candle, wax melts which is a physical change. Also, the wax near the flame burns and gives $CO _2$, soot, light and heat which is a chemical change. Hence, burning of candle is a physical as well as chemical change.

Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

The difference between a physical reaction and a chemical reaction is :

  1. composotion

  2. size

  3. shape

  4. all of above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances. In a physical change, there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. 

Multiple choice chemistry phenomena around us comparison between physical and chemical changes introduction to physical and chemical changes change around us

Physical change include change in :

  1. texture

  2. temperature

  3. formation of bubbles

  4. both a and b
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The texture of a substance can differ with a physical change. For example, if a piece of wood was sanded, waxed, and polished, it would have a very different texture than it initially had like a rough piece of wood. Although, we cannot see temperature change, unless if a change of state is occurring, so it is a physical change. 


Hence, the correct option is $\text{D}$