Write any two observations in an activity which may suggest that a chemical reaction has taken place. Give an example in support of your answer.
Write any two observations in an activity which may suggest that a chemical reaction has taken place. Give an example in support of your answer.
When a chemical reaction takes place,any of these changes can be observed:
>change in color
>change in state
>evolution of gas
>change in temperature
>formation of a precipitate
example: when lead nitrate and pottasium iodide reacts,a yellow precipitate ie,lead iodide is formed.
>when sodium reacts with water, sodium hydroxide is formed along with the evolution of hydrogen gas.
>when green crystals of iron oxide is heated, a successive color change is observed from green to colorless to reddish brown along with sulphur dioxide and sulphur trioxide.
>when quicklime is mixed with water, it forms slaked lime and heat is evoluted and hence there is change in temperature
When a chemical reaction takes place,any of these changes can be observed:
>change in color
>change in state
>evolution of gas
>change in temperature
>formation of a precipitate
example: when lead nitrate and pottasium iodide reacts,a yellow precipitate ie,lead iodide is formed.
>when sodium reacts with water, sodium hydroxide is formed along with the evolution of hydrogen gas.
>when green crystals of iron oxide is heated, a successive color change is observed from green to colorless to reddish brown along with sulphur dioxide and sulphur trioxide.
>when quicklime is mixed with water, it forms slaked lime and heat is evoluted and hence there is change in temperature
