Physical and Chemical Properties

I Can… -Distinguish between a physical-chemical properties and changes. -Apply the law of conservation of mass to chemical reactions. -Distinguish between homogeneous and heterogeneous mixtures. -Compare and contrast compounds, elements, and atoms.

Substances Substances- are matter that has a uniform and UNCHANGING composition Example: Water- pure water- is uniform (same through out) and its composition will ALWAYS be H2O

phase- at room temperature Physical Properties Physical properties- are characteristics that can be observed or measured without changing the samples’ composition. color odor solubility density conduction luster melting point malleable phase- at room temperature boiling point

Physical Properties What is the difference between extensive and intensive properties? Extensive properties are dependent upon the amount of substance that is there. Example- length, volume, shape Intensive properties are independent of the amount of substance present. Example- density, or melting point or boiling point

What are chemical properties? Chemical properties describes the ability of a substance to react with another substance. Ability to catch on fire (flammability) Ability to rust (corrosion) Ability to burn skin (acid)

States of Matter States of Matter Shape volume Particle distance   Shape volume Particle distance Solids Liquids Gases Very close together Definite Definite Undefined- shape of container Particles slide past each other Defined Undefined- shape of container Undefined- Volume Compressible Particles are very very far apart

Physical Change When the appearance changes but not the composition of the substance remains the same is called a physical change. Water is still water whether it’s a solid (ice) or gas (steam) Hair is hair whether its long or cut short Example: Freezing, cutting, crumpling, breaking, crushing and boiling

Chemical Changes A process that involves one or more substances changing into new substances is called a chemical change. Examples- rusting car, burning paper, rotting food, tarnish. 4Fe (solid) + 2 O2 (gas) 4FeO (rust)

How do you know if it’s going through a chemical change? When observing a “change” at least 2 of these have to be present. Temperature change Presence of a gas (bubbles) Color change Odor change Precipitate- solid floaters

Law of Conservation of mass That mass is neither created nor destroyed during a chemical reaction- it is conserved

+ Law of Conservation of mass 2 molecule of H2O- water A chemical change results in a new substance being formed. What happens to the individual atoms during a chemical change? They rearrange to form a new substance. 2 molecule of H2O- water Hydrogen molecule – H2 + Hydrogen molecule – H2 Oxygen molecule – O2

6. From a laboratory process designed to separate water into hydrogen and oxygen gas, a student collected 10.0 g of hydrogen and 79.4 g of oxygen. How much water was originally involved in the process? If 10 grams of hydrogen and 79.4 grams of oxygen are collected, that means there is 89.4 grams of water to start.

7. A student carefully placed 15 7. A student carefully placed 15.6 g of sodium in a reactor supplied with an excess quantity of chlorine gas. When the reaction was complete, the student obtained 39.7 g of sodium chloride. How many grams of chlorine gas reacted? How many grams of sodium reacted? 39.7 grams of sodium chloride was obtained. 15.6 of it was sodium so that makes 24.1 grams of chlorine was used. 15.6 grams of sodium.

8. In a flask, 10. 3 g of aluminum reacted with 100 8. In a flask, 10.3 g of aluminum reacted with 100.0 g of liquid bromine to form aluminum bromide. After the reaction, no aluminum remained, and 8.5 grams of bromine remained unreacted. How many grams of bromine reacted? How many grams of compound were formed? 10.3 g aluminum + (100g – 8.5 g= 91.5g) bromine = 101.8 grams of aluminum bromide

9. A 10. 0-g sample of magnesium reacts with oxygen to form 16 9. A 10.0-g sample of magnesium reacts with oxygen to form 16.6 g of magnesium oxide. How many grams of oxygen reacted? 10 g of magnesium – 16.6 grams of magnesium oxide = 6.6 g of oxygen

Mixtures AND Substances Matter is sorted… By composition. What its made out of What are the two broad categories of separating matter? Mixtures AND Substances

Matter Mixtures Substances

Provide at least 5 examples. Spices blood brass Dirt Pizza

What are mixtures? A mixture is a combination of two or more substances in which each of the substances retain their identity. They can be separated by physical means.

These mixtures can be separated by physical means. Two kinds of Mixtures Define heterogeneous mixture. A mixture that is NOT evenly distributed. These types of mixtures have two or more compositions and are called heterogeneous mixture. It can be very obvious-like a salad or difficult to catch- orange juice (pulp). These mixtures can be separated by physical means.

These mixtures can be separated by physical means. Define homogeneous mixture. A mixture that IS evenly distributed. Homogeneous mixtures are composed of one composition. Homogeneous mixtures are the same composition through out the mixture. Solutions ARE homogeneous mixtures. What are some types of solutions? These mixtures can be separated by physical means.

Matter Mixtures Substances Chemical physical Heterogeneous Homogeneous-(Solutions) Same through out Not the same through out

What are compounds? Chloride Sodium What are elements? Are types of pure matter that can be broken down into simpler substances. Chloride Sodium What are elements? Are types of pure matter that can not be broken down into simpler substances. Elements are the simplest form of matter.

Matter Mixtures Substances physical Chemical Heterogeneous Fixed composition/properties physical Chemical Heterogeneous Homogeneous-(Solutions) Same through out Compounds Elements Not the same through out Can be broken down Can’t be broken down H2O H2O2 CO2 H2 O2 C

Examples of Substances C12H22O11 Sugar NaCl Salt Au gold Cl Chlorine I Iodine C3H7OH Alcohol H2O Water CO2 Dry Ice S Sulfur Na Sodium O Oxygen

Sort the substances Elements Compounds I Iodine C12H22O11 Sugar Cl Chlorine NaCl Salt CO2 Dry Ice O Oxygen S Sulfur C3H7OH Alcohol H2O Water Na Sodium Au gold

Define Law of definite proportions- Law of multiple proportions Regardless of the amount, a compound is always composed of the same elements in the same proportion by mass. H2O- 2 grams come from hydrogen and 16 grams of oxygen. Basically- that different compounds CAN be made of the same elements but in different proportions. H2O2 and H2O