can someone help me?

 

1) Suppose that a reaction was carried out in an open flask and the final mass was significantly greather than the initial mass. What would you conclude?

2) Suppose that a reaction was carried out in an open flask and the final mass was significantly less than the initial mass. What would you conclude?

1) the reaction involved the air, so some of the gas was combined with the reactants to form the heavier product.

2) you would conclude that some of the products of the reaction escaped, probably in gaseous form.

(1) Heating "light" reactive metal in air, such as lithium would greatly increase the mass.

1) it had gained mass from somewhere and requires further investigation.

2) it had lost mass somewhere and requires further investigation.

 

that`s about all you can "Conclude" when given the parameters that you gave.

pretty darn safe to say that my predictions were right though I dont see what else could have happened in highschool chemistry experiment.

highschool or anything else was not given as a parameter though!

Or that Air was what the open flask was exposed to.

1) substance from the air has reacted and the product is denser than air so it sinks into the vail.

2)substance from the air has reacted and the product is less denser than air so it diffuses out of the vail.