Unit 1: Chemical Reactions
What type of reaction is represented by the equation (2 KClO3 --> 2 KCl + 3 O2
What is Decomposition
How many moles of H₂O can be produced from 3.5 moles of O₂ in the reaction (4 NH₃ + 5 O₂ --> 6 H₂O + 4 NO)?
What is 4.2 moles H2O
3.5 moles O₂ x (6 moles H2O / 5 moles O2) = 4.2 moles H₂O
What is the molarity of a solution made by dissolving 25.0 g of NaCl in 500.0 mL of water?
NaCl: 58.44 g/mol
What is 0.86 M
Grams -> moles = 0.43 mol
mL -> L = 0.5 L
mol/L = 0.43/0.5 = 0.86 M
What is the pH of a 0.005 M HCl solution?
-log(0.005)
Which law states that at constant temperature, pressure is inversely proportional to volume?
What is Boyle's Law
Balance the equation: ___ Na + ___ Cl₂ → ___ NaCl.
What is 2,1,2
How many grams of NH₃ are required to produce 8.5 moles of H₂O?
(4 NH₃ + 5 O₂ --> 6 H₂O + 4 NO)?
What is 96.5 g NH3
8.5 moles H2O x (4 moles NH3 / 6 moles H2O) x (17.03 g NH3 / 1 mol NH3) = 96.5 g NH3
How many grams of KOH are needed to prepare 2.0 L of a 0.75 M solution?
What is 84.16 g KOH
mol = L x M
2.0 L x 0.75 M = 1.5 mol
mol -> grams = 84.16 g KOH
What is the hydroxide concentration of an NaOH solution whose pOH is 11.6?
What is 2.51x10-12 M
10-11.6
A gas is at 1.5 atm and 300 K. What is the new pressure at 450 K, assuming volume stays constant?
What is 2.25 atm
(1.5/300) = (P2/450) cross multiply to solve
What is the molar mass of NH₃
What is 17.03 g/mol
H (3 x 1.008) = 3.024
N (1 x 14.007) = 14.007
3.024 + 14.007 = 17.03 g/mol
How many grams of O₂ are needed to react with 68.0 g of NH₃ in the reaction (4 NH₃ + 5 O₂ --> 6 H₂O + 4 NO)?
What is 159.72 g O2
68.0 g NH3 x (1 mol NH3 / 17.03 g NH3) x (5 mol O2 / 4 mol NH3) x ( 32 g O2 / 1 mol O2)
If you dilute 1 L of a 0.50 M CuSO₄ solution to 2.0 L, what will the new molarity be?
What is 0.25 M
M1V1 = M2V2
(1 x 0.5)/ 2 = 0.25 M
If 50 mL of an unknown concentration acid is titrated with a 1.0 M NaOH solution and requires 53 mL of NaOH, what is the concentration of the acid?
What is 1.06 M
(53 x 1) / 50
Calculate the pressure of 0.50 mol of gas in a 10.0 L container at 273 K using the Ideal Gas Law.
What is 1.12 atm
(0.5 x 0.0821 x 273) / 10
What is avogadro's number?
What is 6.02x1023 particles
Calculate the percent yield if Na reacts to produce 175.0 g of NaCl with a theoretical yield of 190.0 g.
What is 92.11%
(Actual / Theoretical) x 100%
(175 / 190) x 100%
Calculate how much 6.0 M HCl is needed to prepare 500.0 mL of 1.5 M HCl
What is 125 mL
(500 x 1.5) / 6
If 25 mL of an unknown concentration acid requires 50 mL of 0.5 M NaOH for titration, what is the concentration of the acid?
What is 1 M
(50 x 0.5) / 25
If a gas has a volume of 3.0 L at 2.0 atm, what will the new volume be if the pressure is changed to 1.0 atm?
What is 6 L
(3x2) /1
How many molecules are present in 4.5 moles of H₂O?
What is 2.71x1024 molecules
4.5 moles x (6.02x1023 molecules)
Identify the limiting reactant in the reaction (2 Al + 3 Cl₂ --> 2 AlCl₃) if starting with 10.0 g of Al and 25.0 g of Cl₂.
AL: 26.982 g/mol
Cl2: 70.9 g/mol
AlCl3: 133.33 g/mol
What is Cl2
Grams Al --> Moles Al --> Moles AlCl3 --> Grams AlCl3 = 49.4 g AlCl3
Grams Cl2 --> Moles Cl2 --> Moles AlCl3 --> Grams AlCl3 = 31.3 grams AlCl3
What happens to the molarity if you add more NaCl to a 1.0 M NaCl solution without changing the volume?
What is the molarity increases
Explain the difference between the endpoint and the equivalence point in a titration.
What is The equivalence point is when moles of acid equal moles of base, while the endpoint is when the indicator changes color
If you have a gas in a flexible container that has an original pressure P, what would be the new pressure if you triple the temperature?
What is triple the pressure
Gay-Lussac's Law - directional proportional