what   happens in  the  reaction  flask?

do you think that  a  chemical  reaction  has  taken place?

why  should  we put a cork on the mouth  of the flask?

does  the  mass  of  the  flask  and it s  contents  change?

Hi,

In the reaction flak, the reaction takes place. If you take example given for the law of conservation of mass , we see that before mixing the two reactants, the mass was same as it is after mixing the reactants to form products. Thus inside the flask the reaction has taken place.

 

We should cork the mouth of flask so that neither the reactants nor the products escapes out of the flask which otherwise can cause error in reading the mass. Mass of the flask does not change but the content of the flask has changed due to reaction in the flask.