Amixture is -
a. a chemical combination of two or more different materials.
b. a physical combination of two or more different materials.
c. a precipitate and its solution.
d. a single element.

State one important difference between a physical change and a chemical change?

What is the volume of 2.5 moles of nitrogen gas (n2)at standard temperature and pressure (stp)?

Which of these describes the rate of this chemical reaction? h2 + cl2 → 2 hcl a. an increase in the concentration of hcl and h2 with time b. an increase in the concentration of hcl with time c. an increase in h2 and cl2 with time d. a decrease in hcl and cl2 with time