During an experiment a thermometer was placed in a beaker containing hydrogen peroxide. The following observations were recorded when yeast granules were added to hydrogen peroxide.
Observation 1. Fizzing and bubbling took place
Observation 2. The temperature began to rise.
Based on the observation, justify the type of change (physical or chemical) that took place.

Both the observations are a type of chemical change

Explanation:

A physical change is defined as the change which occurs when there is no change in the composition of a substance. The physical state of the substance is changed. No new substance is formed.

A chemical change is defined as the change which occurs when there is change in the composition of a substance. New substance is formed at the end of the reaction.

There are many indicators which show us that a chemical change is happening in the reaction:

Change in color

Formation of bubbles

Change in temperature

Formation of precipitate

Characteristic Odor

For the observations given in the question:

Observation 1. In this observation, the temperature is being decreased because this reaction is an endothermic process. As there is change in temperature, hence it is considered as a chemical change.

Observation 2: In this observation, gas bubbles are formed due to the release of carbon dioxide gas. As there is formation of bubbles in this reaction. Hence, it is considered as a chemical change.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

4d^55s^1 ( third choice)