Question

Ben and Sam were conducting experiments on physical and chemical changes in science class. First they added some salt to water and stirred it up until the salt dissolved. "That's a physical change" Ben said. "And that's a solution which is a mixture", added Sam. Next they added an anti-acid tablet to some water. The water began to fizz and bubble. The beaker got cooler. "That's a physical change too," Ben noted. "No, it's not," responded Sam. Who is correct

Answer 1

assuming that B and S are not in the arctic (where a cold draught would affect things), the key to this q seems to lie in "The beaker got cooler" which suggests an ENDOTHERMIC (takes heat in from outside, and so outside gets cooler) CHEMICAL reaction with whatever is in the anti acid tablet. Endothermic means TAKES IN HEAT (rather than EXO thermic which would be gives out heat and gets warmer). So yes the salt dissolved in the water, but it could be recovered by distillation, I think. However, the tablet contents ... probably NOT by a PHYSICAL MEANS only
I'd guess that S is correct, it's a CHEMICAL CHANGE.
http://perendis.webs.com

Answer 2

Thank you so much!!!

Answer 3

@GraceBooth you are very welcome. good on you.