AP Chem: States of Matter – Flashcards
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Unlock answersWhat is the pressure exerted by 5 moles of gas in a 40 L container at 300 K? |
Using the ideal gas equation, you can calculate the pressure exerted by the gas is about 3.1 atm. |
How many atoms of a substance are in 1 mole of that substance? |
In 1 mole of a given substance, there are 6.022 x 1023 atoms. |
On the periodic table, the masses given for the elements are masses for what quantity of the element? |
The masses given for the elements are for 1 mole of the element. |
Polar substance will only dissolve what other type of substances? |
Other polar substances |
In order for a solvent to dissolve a solute, what must be overcome? |
In order for a solvent to dissolve a solute, intermolecular forces must be overcome. |
What is the freezing point depression equation? |
Tf= kf x msolute |
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List the three states if matter in order of increasing density |
Gas: neither definite shape nor volume
Liquid: definite volume; takes shape of container
Solid: definite size and shape |
Phase Two examples |
A sharply defined, uniforme region in a mixture.
Examples- oil and vinegar in salad dressing; ice and water in a frozen pond |
Density General equation and three standard units |
The mass of a unit volume of a substance.
Density = mass/volume
g/mL g/L kg/L |
Calculate the density of a rock with mass = 10g and volume = 5mL |
Density = mass/volume
density 10 g/5 mL = 2 g/mL |
Element List some examples |
A substance composed of identical atoms.
gold, silver, oxygen, hydorgen, lead, chlorine, helium, iron, copper, fluorine, arsenic |
Compound List some examples |
Substance composed of two or more different elements chemically combined. For example: Water - H2O Salt - NaCl Sugar - C6H12O6 Ammonia - NH3 |
Mixture List some examples |
A combination of substaces held together by physical means. (Dirt, milk, soup, saltwater, granite) |
Homogenous ang heterogenous Mixture Give example |
Homogeneous mixtures are uniforme in composition. (Air, metal, alloy, salt water) Hetergeneous mixtures are not uniform in composition. (Dirt, spaghetti sauce) |
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Einstein's law of conservation of energy |
The sum-total of mass and energu remains constant in a reaction but mass and energy may be interconverted. E = mc2 E= energy; m = mass c= speed of light |
Identify as element, compound, or mixture Sand, air, gold, water, salt, hydrogen |
Sand - mixture Air - mixture Gold - element Water - compound Salt - compound Hydrogen - element |
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PRESSURE Write Normal Atmospheric Pressure in Five Standard Units ; |
Pressure is force per unit of area ; 1 atmosphere= 760 torr = 760 mm Hg = 101.3 kilopasca;s = 14.7 pounds/square inch |
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State three postulates of: The Kinetic Molecular Theory of gases |
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State the formula for Graham's Law of Diffusion.Do heavy or light gases diffuse faster? |
A mixture of a gas A & B: (RA)(MWA)1/2 = (RB)(MVB)1/2 MWA,MWB = Molecular weights RA, RB = Rates of Diffusion (Light gases diffuse faster) |
Charles' Law |
V1/T1 = V2/T2 Pressure and amount of gas are constant V = volume T = Kelvin |
At 300 K a gas has a volume of 10 liters. Find the volume at 400 K |
Use Charles' Law, V1/T1 = V2/T2 10/300 = V2/400 V2 = 13.3 L |
Boyle's Law |
P1;x V1 = P2 x V2 Pressure and volume are inverse if temperature and amount of gas are constant P = pressure V = volume |
A sample of gas has a volume of 23 L at 800 torr. find the volume at 400 torr. |
Use Boyle's Law P1 x V1 = P2 x V2 25 x 800 = 400 x V2 V2 = 50 L |
Combined Gas Law |
P1V1/T1 = P2V2/T2 Amount of gas is constant P = pressure V = volume T = kelvin |
Dalton's Law of Partial Pressure |
In a gas mixture, the total pressure equals the sum of the partial pressures of each component Ptotal = P1 + P2 + P3 ... |
Ideal Gas Law |
PV = nRT P = pressure (Atmospheres) V = volume (Liters) n = # of Moles R = 0.0820 L-ATM/MOL-K T = temperature in K |
How many moles of H2 gas are there in 20 L at 4 atm and 400 K? |
Use the Ideal Gas Law PV = nRT ; (4 atm)(20 L) = n(0.082)(400) n = 2.44 moles |
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N2 + 3H2 ; 2NH3 In the above reaction how many L of NH3 will be produced from 6L H2 ; |
According to Gay-Lussac's Law the volumes of gases are in direct proportion to the coefficients in the equation. H2 : 3/6 L = NH3 : 2/x x = 4L of ammonia
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Sublimation |
The change from a solid to a vapor without the forming of a liquid Compounds which show sublimation (CO2, I2) |
Describe a phase change from liquid to gas |
When a molecule gains enough kinetic energy to overcome the intermolecular attractive forces within a liquid, it escapes the surface and becomes gas. |
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Normal Boiling Point |
The temperature at which a liquid phase becomes a gas phase when vapor reaches atmospheric pressure. Pressure = 1 atm |
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Melting Point |
The temperature at which the solid and liquid phases co-exist |
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Define boiling point in terms of vapor pressure |
The temperature at which the vapor pressure over a liquid reaches atmospheric pressure. The substance boils (liquid to gas) |
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10g x 540 cal/g = 5400 cal
2. Heat of fusion of water is 80 cal/gram (0.5 grams)(80 cal/gram) = 40 cal |