Chemistry

2. a change that alters a substance without changing its composition
3. a procedure in which the concentration of a solution is determined by comparing it to a solution of known concentration
5. a device used to measure the energy absorbed or released as heat in a chemical reaction
6. the species that results when an acid donates a hydrogen ion to a base
12. a change in matter in which new materials with mew chemical and physical properties are formed
13. the random movement of gas molecules from an area of higher concentration to an area of lower concentration
15. transition of a substance directly from solid to gas
16. transition of a substance directly from gas to solid
17. the point on a phase diagram in which two phases of substance become indistinguishable from each other, a supercritical fluid
18. diffusion through a tiny opening
19. the species produced when a base accepts a hydrogen ion from an acid

1. a characteristic that can be observed or measured without changing the sample's composition
4. the ability of substance to combine with or change into one or more other substance
7. a substance that increases the concentration of hydrogen ions in an aqueous solution
8. a substance that increases the concentration of hydroxide ions in an aqueous solution
9. a compound that can act as either an acid or base
10. the temperature and pressure at which the solid, liquid, and gas forms of a substance coexist
11. the amount of space the gas takes up
13. occurs when solutions of two aqueous compounds are combined; the positive and negative ions of each compound exchange places
14. biological catalysts that speed up the rate of reactions in the body