Tag: chemistry

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Questions Related to chemistry

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

Cooking of rice is an example of:

  1. irreversible change

  2. endothermic reaction
  3. both $A$ & $B$

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

Cooking of rice is both irreversible and endothermic reaction. i.e once cooked rice cannot be made rice back and the rice absorbs heat from the external sources and utilizes for its cooking so it is endothermic.

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

The growth of seedlings in a crop is a:

  1. undesirable change

  2. desirable change

  3. reversible change

  4. physical change
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The growth of seedlings in a crop is a desirable change i.e the changes which are beneficial to nature or which does not cause any harm to nature.

Few of the examples are curdling of milk, seed germination etc...

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

A seed growing into a tree is an example of:

  1. slow physical change

  2. fast periodic change

  3. slow natural change

  4. man-made reversible change
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A seed growing into a tree is an example of a slow and natural process. Slow because it takes days to sometimes months for a seed to develop into a sapling and then years to a develop into a tree. All these processes occur naturally using all natural resources like water, sunlight, soil.

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

What's common among motion of the planets around the sun, blinking of traffic lights and motion of blades of a fan rotating at uniform speed?

  1. Irreversible changes

  2. Chemical changes

  3. Periodic changes

  4. Undesired changes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The planets around the sun, blinking of traffic lights and motion of blades of a fan rotating at uniform speed are all periodic changes.
Changes which are repeated after regular intervals are called periodic changes.

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

If two substances interact to produce a change, they will do so:

  1. under any condition

  2. no matter what kind of interaction there is

  3. only if the interaction is of the right kind and under the right conditions

  4. only if they are in close contact with each other
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to transition state theory, two molecules interact with each other when they are aligned in a proper orientation.

Hence, two substance interact to produce a change only if the interaction is of the right kind under right conditions.

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

Halley's comet revolves around the sun once in every 76 Years. This is a:

  1. photochemical change

  2. periodic change

  3. chemical change

  4. irreversible change
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is a periodic change $-$ because changes that occur after a fix interval of time is known as periodic change.

Here periodic change in $76$ years
photochemical change is due to light chemical change $-$ where reactant react to produce products.

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

Iron pipes coated with zinc do not get rusted easily.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

It is true.

Coating iron with zinc is known as galvanizing. Iron metals get rusted when in contact with oxygen and moisture (air).
If coated with zinc, no interaction between oxygen and iron is there and hence the pipe does not get rusted easily.

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

When an iron nail is added to acidic copper sulphate solution, the colour of the deposit on the iron nail is:

  1. brown

  2. blue

  3. green

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

When a nail is added to acidic copper sulphate solution, the color of the deposit on the iron nail is brown. Copper sulphate reacts with iron to form iron sulphate and copper. Brown colored copper deposits on nail.

Multiple choice chemistry phenomena around us changes and its classification types of changes classification of changes

A change in which a substance undergoes changes in its physical properties is called:

  1. chemical change

  2. physical change

  3. no change

  4. biological change
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A change in which a substance changes its physical properties like appearance, texture, colour, odour, melting points, boiling points, density, solubility, polarity etc... are called physical changes. 


Physical properties can be observed or measured without changing the composition of matter. They are used to observe and describe matter.

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