Question

A chemist is performing a chemical reaction under a fume hood. The chemist has a set of beakers,flasks, and tubes set up under the fume hood, with various liquids being combined inside the glasscontainers. The fume hood is turned on in order to withdraw any toxic gases and expel themoutside the building.
Which part of this system is designated as the chemical reaction system?
(1 point)
Substances reacting in lab glassware
inside the fume hood
outside the building
the glass containers
A)
In order to break water into hydrogen and oxygen, water is heated to more than 500ºC. Which kind of reaction is this and why?
(1 point)
It is endothermic because heat needs to be absorbed by the reactants to form the products.
It is endothermic because heat needs to be released by the reactants to form the products.
It is exothermic because heat needs to be released by the reactants to form the products.
It is exothermic because heat needs to be absorbed by the reactants to form the products.

Answer 1

1) Substances reacting in lab glassware — the chemical system is the reactants/products undergoing the reaction (the materials inside the glassware).

2) It is endothermic because heat needs to be absorbed by the reactants to form the products. Heating supplies energy to break the O–H bonds in water.