OB: Compounds + Elements, the Law of Conservation of Matter

We will discuss the conclusion for the penny lab, due Friday,

Also take out HW #1

Review of yesterday:

Elements are limited in number, pure, listed on the periodic table and, cannot be made simpler

Compounds form when 2 or more elements chemically combine into a new pure substance, with unique properities, and a specific ratio of atoms to atoms

Mixtures are just mixed up combinations of stuff, no ratios, no recipes, and can be physically separated. There are no new properties formed. Mixtures can be heterogeneous or homogeneous.

MATTER

Pure substancesall homogeneous

Mixtures(heterogeneous or

homogeneous)

Elementsexamples: Mg, Ca, Fe

Compoundsexamples: H20, CO2, NaCl

Homogeneousexamples:

air, tap water, includes all solutions

Heterogeneousconcrete, soup,

sugar + salt in a bowlsand + iron BB’s

The Law of Conservation of Matter

Matter cannot be created or destroyed in any chemical reaction (or physical change).

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Iron + oxygen yields iron oxide

Iron and oxygen are the __________________

Iron oxide is the ______________________

The mass of the _____________ equals the mass of the __________

223 g Iron + 96 g Oxygen ______ Iron Oxide

4 g hydrogen + X g oxygen 36 grams water

223 g Iron + 96 g Oxygen 319g Iron Oxide

223 g + 96 g = 319 g

4 g hydrogen + 32 g oxygen 36 grams water

4 g + X g = 36 g

X = 32 g

8 g hydrogen + 64 g oxygen will form into ____ g water 

____ g hydrogen + 28 g nitrogen 34 g ammonia (NH3)

8 g hydrogen + 64 g oxygen make how many g water? ______

8 g + 64 g = 72 g

____ g hydrogen + 28 g nitrogen 34 g ammonia (NH3)

X g + 28 g = 34 gX = 6 g hydrogen

Home work #1 take out

Then, Density by Displacement Lab Conclusion