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States of Matter
Stoichiometry
Equilibrium
The Mole
Solutions
100
When a solid changes to a liquid it is called what?
What is melting
100
A sample contains 27.1 g of calcium oxide. How many moles of calcium oxide are in the sample?
What is 0.483 mol CaO
100
For a system at equilibrium, which of the following are true? a) The rate of the reaction is zero. b) The concentrations of reactants and products are no longer changing. c) The value for the equilibrium constant, K, will change when temperature is changed. d) The rate of the forward reaction is equal to the rate of the reverse reaction.
What is B, C, D
100
How many moles are in the following: a. 1.29 x 1024 hydrogen atoms in HF
What is 2.14 moles H atoms
100
A 0.750 L aqueous solution contains 90.0 g of ethanol, C2H5OH. Calculate the molar concentration of the solution in mol·L-1
What is [C2H5OH ] = 2.60M
200
True or false? Liquids are easy to compress.
What is False
200
How many liters does 3.8 moles of O2 occupy at STP (standard temperature and pressure)?
What is 85.12 L O2
200
For each reaction below, write an expression for K and indicate what effect an increase in pressure would have on equilibrium. a) H2(g) + S(s) H2S(g) b) N2(g) + 3 H2(g) 2 NH3(g) c) H2(g) + Br2(l) 2 HBr(g)
What is a) K = [H2S]/[H2]; no effect b) K = [NH3]2/[N2] x [H2]3; more product made. Increasing the pressure increases the concentration; counteract this by shifting to the side with fewer moles c) K = [HBr]2/[H2]; more reactant made
200
How many moles 7.36 x 1024 free oxygen atoms
What is 12.2 moles O atoms
200
What mass of NaCl are dissolved in 152 mL of a solution if the concentration of the solution is 0.364 M?
What is 3.24 g
300
When a gas changes into a liquid it is called what?
What is Condensation
300
A solution of NaCl has a molarity of 0.549 M. How many moles are in 350. mL of this solution?
What is 0.193 mol NaCl
300
For the equilibrium in Question 3b, K is 4.51 x 10-5 at 450(C. Is a mixture containing 100 atm NH3, 30 atm N2 and 500 atm H2 at equilibrium? If not, will the mixture shift toward product or reactants to achieve equilibrium?
What is 2.7 x 10-6 ( Q < k Not at equilibrium and more product will be formed (to make Q larger).
300
What mass of Ni has as many atoms as there are N atoms in 63.0 g of NO2? As Na atoms in 63.0 g of NaCl?
What is 80.4 g Ni, 63.3 g Ni
300
What mass of dextrose, C6H12O6 is dissolved in 325 mL of 0.258 M solution?
What is 15.1 g
400
When solids reach their melting points they become what?
What is Liquids
400
If 120. g of propane, C3H8, is burned in excess oxygen, how many grams of water are formed?
What is 196g H2O
400
A mixture of 0.100 mol of NO, 0.050 mol of H2, and 0.100 mol of H2O are placed in a 1.00-liter flask. The following equilibrium is established: 2 NO(g) + 2 H2(g) N2(g) + 2 H2O(g) At equilibrium, [NO] = 0.070 M. a) Calculate the equilibrium concentrations of H2, N2, and H2O. b) Write an expression for K for this reaction. c) Calculate K for this reaction. d) At equilibrium, how will the concentrations of products compare to the concentrations of reactants?
What is [NO] (M) [H2] (M) [N2] (M) [H2O] (M) original 0.100 0.050 0 0.100 change - 0.030 - 0.030 +0.015 + 0.030 equilibrium 0.070 0.020 0.015 0.130
400
How many g of CaCO3 are present in a sample if there are 4.52 x 1024 atoms of carbon in that sample?
What is 751 g CaCO3
400
A mass of 98 g of sulfuric acid, H2SO4, is dissolved in water to prepare a 0.500 M solution. What is the volume of the solution?
What is 2.00 L
500
What is it called when a solid changes directly into a gas?
What is Sublimination
500
90.0 g of FeCl3 reacts with 52.0 g of H2S. What is the limiting reactant? What is the mass of HCl produced? What mass of excess reactant remains after the reaction?
What is 60.8g HCL
500
At 1500 K, the equilibrium constant for the reaction, N2(g) + O2(g) 2 NO(g), is 1.0 x 10(5 . Calculate the equilibrium concentrations of N2, O2 and NO if, before any reaction, 0.500 mol of NO is placed in a 1.00-liter container. (Ignore significant digits for NO.)
What is [N2] (M) [O2] (M) [NO] (M) original 0 0 0.50 change + x + x ( 2x equilibrium x x 0.50(2x
500
At 25º C, the density of water is 0.997 g/ml. At -10º C, the density of ice is 0.917 g/cm3. If a bottle with a volume of 275 mL were filled fully with water at 25º C and then frozen to -10º C, could the ice still be contained in the bottle? What would the volume of the ice be?
What is No. 253 mL
500
A solution of sodium carbonate, Na2CO3, contains 53.0 g of solute in 215 mL of solution. What is its molarity?
What is [Na2CO3 ] = 2.33 M