Tag: chemistry

Questions Related to chemistry

Cooking of rice is an example of:

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

  1. irreversible change

  2. endothermic reaction

  3. both $A$ & $B$

  4. none of the above

Show answer
Correct Option: C
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.

The growth of seedlings in a crop is a:

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

  1. undesirable change

  2. desirable change

  3. reversible change

  4. physical change

Show answer
Correct Option: B
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...

A seed growing into a tree is an example of:

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

  1. slow physical change

  2. fast periodic change

  3. slow natural change

  4. man-made reversible change

Show answer
Correct Option: C
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.

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?

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

  1. Irreversible changes

  2. Chemical changes

  3. Periodic changes

  4. Undesired changes

Show answer
Correct Option: C
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.

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

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

  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

Show answer
Correct Option: C
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.

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

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

  1. photochemical change

  2. periodic change

  3. chemical change

  4. irreversible change

Show answer
Correct Option: B
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.

Which of the following is not considered a temperature scale? 

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

  1. Fahrenheit

  2. Kelvin

  3. Calorie

  4. Celsius

Show answer
Correct Option: C
Explanation:

Calorie is used to measure the amount of energy needed to raise the temperature of one gram/kilogram  of a substance like water by one degree.

Iron pipes coated with zinc do not get rusted easily.

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

  1. True

  2. False

Show answer
Correct Option: A
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.

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

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

  1. brown

  2. blue

  3. green

  4. pink

Show answer
Correct Option: A
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.

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

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

  1. chemical change

  2. physical change

  3. no change

  4. biological change

Show answer
Correct Option: B
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 $\text{B}$