Gas Laws
Empirical and Molecular Formula
Excess/Limiting
Conversions
Other
100
What happens to the space between the gas molecules in an airbag if it deploys at a higher altitude?
The space between the gas molecules increases
100
How do you find the empirical formula?
1. Start with the number of grams of each element, given in the problem. (If percentages are given, assume that the total mass is 100 grams so that) 2. Convert the mass into moles. 3. Divide each mole value by the smallest number of moles calculated. (Round to the nearest whole number)
100
1 H3PO4 + NaHCO3→1 Na3PO4 + 3 H2O+ 3 CO2 You have 10 grams of H3PO4 and 10 grams of NaHCO3. How much CO2 will I produce at STP?
10.00g H3PO4(1 mole/98g H3PO4 )(3 NaHCO3/1 H3 PO4)(84g NaHCO3/1 mole)=25.7g NaHCO3 10.00g NaHCO3(1 mole/84g NaHCO3)(1 H3PO4/3 NaHCO3)(98g H3PO4/1 mole)=3.98g H3PO4 10.00g H3PO4-3.89g H3PO4 = 6.11g excess H3PO4
100
The number of particles in a mole
What is 6.02 * 10^23?
100
What happens to volume of the individual gas molecules in an airbag if it deploys at a higher altitude?
The volume of the individual gas molecules remains the same
200
Theoretically the volume of an ideal gas is zero at -273 C because ______
the molecular motion of gas molecules becomes zero at this temperature
200
What is the empirical formula of the 1.35g Al, 2.40g S, and 3.60g O compound?
1.35g Al (1mole/27g Al) = .050 2.40g S (1mole/32.1g S) = .075 3.60g O (1mole/16g O) = .225 .050/.050 = 1 * 2 = 2 .075/.050 = 1.5 * 2 = 3 .225/.050 = 4.5 * 2 = 9 Al2S3O9
200
How do you find the limiting reactant?
1. Balance the chemical equation. 2. Convert the number of grams of reactants to the number of moles of reactants. 3. Compare the ratios of the reactants to the stoichiometry of the balanced equation. Divide the number of moles of each reactant by the number of atoms or molecules required for the reaction. 4. Determine the amount of the other reactants required to completely exhaust the amount of a single reactant. The reactant with the least amount to satisfy the balanced equation is the limiting reactant.
200
Convert 0 degrees Celsius into Kelvins
273.15K
200
What happens to the volume of an airbag if it deploys at higher altitude assuming the atmospheric pressure is lower at higher altitudes?
The volume of the airbag is inversely proportional to its pressure therefore the volume will increase as the pressure decreases.
300
The combined and the ideal gas laws.
What are P1V1/T1 = P2V2/T2 and PV=nRT
300
You have 4g H, 24g P, and 2g O. What is the percent of hydrogen, phosphorus, and oxygen in phosphoric acid?
%H = 100(4/30) = 13% %P = 100(24/30) = 80% %O = 100(2/30) = 7%
300
C3H8 + 5 O2 --> 3 CO2 + 4 H2O How many moles of carbon dioxide are formed from 88g of C3H8?
88g C3H8 (1mol/44g C3H8)(3 CO2/1 C3H8) = 6 moles CO2
300
Number of Liters in a mole
What is 22.4L
400
What is the Avogadro Pricipal?
If the amount of gas in a container is increased, the volume increases. If the amount of gas in a container is decreased, the volume decreases. V/N=R (constant)
400
What is the difference between the empirical formula and the molecular formula?
Molecular formula is the formula showing the type of atoms and number of each atom connected in the molecule where the Empirical formula gives the simplest integer ratio of each atom of the molecule.
400
4 Al(s) + 3 O2(g) --> 2 Al2O3 You are given 100.0 g of Al react with 100.0 g of O to form Al203. Which reactant is limiting? How many grams of Al2O3 are produced?
100g Al (1mole/27g Al)(3 O2/4 Al)(32g O2/1mole) = 88.9g O2 100g O2(1mole/32g O2)(4 Al/3 O2)(27g Al/1mole) = 113g Al O2 is in excess and Al is limiting 100g Al(1mole/27g Al)(2 Al2O3/4 Al)(102g Al2O3/1mole) = 189g Al2O3 produced
400
What is R. (Name all of the conversions... bwahaha)
the constant R = 0.0821 liter•atm/mol•K R = 8.3145 J/mol•K R = 8.2057 m3•atm/mol•K R = 62.3637 L•Torr/mol•K or
400
How do you find the molecular formula?
1. Find the formula mass of the empirical equation using the periodic table. 2. Divide the molecular weight by the formula mass. 3. Multiply each element in the empirical formula by the whole number calculated when you divided the molecular weight by the formula mass.
500
1 H3PO4 + 3 NaHCO3 --> 1 Na3PO4 +3 H2O + 3 CO2 I have 10g of H3PO4 and 10g of NaHCO3. How much CO2 will I produce at 143.9 KPa at 37degrees Celsius?
10g NaHCO3 (1mole/84)(3/3)= .120 mol CO2 V=(nRT)/P (.120mol)(8.31)(23 + 273)/100kPa = 2.93L CO2
500
CH2O has a mass of 120, what is it's molecular formula?
C4H8O4
500
Percent Yield
What is (Experimental/Theoretical) * 100
500
1 N2 + 3 H2 --> 2 NH3 If 56g of nitrogen react _________ grams of hydrogen are needed and _______ grams of ammonia will be produced
12g H2 and 68g NH3 1. convert to moles 2. coefficients 3. convert to grams
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