2.) is a measure of the mass of an object in a given volume.

3.)A(n) is easily observed or measured without changing the object.

4.) result in a new substance and cannot be reversed by physical means.

5.)Solid, liquid, and gas are all examples of

2. Density

3. Physical Property

4. Chemical Change

5. states of matter

Explanation: Density is referred as mass per unit volume. Physical properties are observable characteristics of an object. An new formation of a substance in a chemical reaction is a chemical change. And solids, liquids, and gases are states of matter.

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.