Equilibrium and Kinetics Bell Ringers Part 4 – Show all Work Name:______
3/28/11 –Review Gases Practice HW: Solutions
How many valence electrons are in each of the following elements and which symbol represents an atom in the ground state with the most stable valence electron configuration?
(1) B
(2) O
(3) Li
(4) Ne
3/29/11 – Review Periodic Trends HW:CST Practice Exam 1-9, 66-77, and 40-55
A scientist observed changes in the gas pressure of one mole of a gas in a sealed chamber with a fixed volume. To identify the source of the changes, the scientist should check for variations in the
a. air pressure outside the chamber. c. temperature of the chamber
b. molecular formula of the gas d. isotopes of the gas
Which of the following has the largest atomic radius?
a. iodine (I) b. magnesium (Mg) c. chlorine (Cl) d. barium (Ba)
Copper (II) nitrate and sodium hydroxide solutions react in a test tube as shown below.
Cu(NO3)2 (aq) + 2NaOH(aq) D Cu(OH)2 (s) + 2NaNO3(aq)
If nitric acid is added to the test tube, the amount of solid precipitate decreases. The best explanation for this is that the acid
a. reacts with the copper (II) nitrate, pulling the equilibrium to the left.
b. dilutes the solution making the precipitate dissolve.
c. will dissolve most solids, including sodium nitrate.
d. will react with the copper (II) hydroxide to form water and soluble copper (II) nitrate.
3/30/11 – Nuclear Chemistry Review: Alpha, Beta, Gamma Decay and Half-life Problems HW:10-19, 56-65
A young adult male produces about 2.4 x 10-5 mol per day of the steroid sex hormone testosterone.
The molecular mass of testosterone is 288. How many grams of testosterone per day does a young adult male produce?
In which type of reaction do two or more substances combine to produce a single substance?
(1) synthesis (2) decomposition (3) single replacement (4) double replacement
Which element has an atom with the greatest tendency to attract electrons in a chemical bond?
(1) carbon (2) chlorine (3) silicon (4) sulfur Why?
Which quantities must be equal for a chemical reaction at equilibrium?
(1) the activation energies of the forward and reverse reactions
(2) the rates of the forward and reverse reactions
(3) the concentrations of the reactants and products
(4) the potential energies of the reactants and products
3/31/11 – Organic Chemistry, Empirical Formulas, Concentrations HW: 20-39, 78-90
A phase change for carbon dioxide that occurs spontaneously at 20.°C and 1.0 atmosphere is represented by the balanced equation: CO2(s) + energy →CO2(g)
Write the name of this phase change.
Describe what happens to the potential energy of the CO2 molecules as this phase change occurs.
Given the balanced equation representing a reaction:
CaO(s) + CO2(g) →CaCO3(s) + heat
What is the total mass of CaO(s) that reacts completely with 88 grams of CO2(g) to produce 200. grams of CaCO3(s)?
(1) 56 g
(2) 88 g
(3) 112 g
(4) 288 g
Given the balanced equation representing a phase change: C6H4Cl2(s) + energy → C6H4Cl2(g)
Which statement describes this change?
(1) It is endothermic, and entropy decreases.
(2) It is endothermic, and entropy increases.
(3) It is exothermic, and entropy decreases.
(4) It is exothermic, and entropy increases.
Which solution has the highest boiling point at standard pressure? And Why?
(1) 0.10 M KCl(aq) (2) 0.10 M K2SO4(aq) (3) 0.10 M K3PO4(aq) (4) 0.10 M KNO3(aq)
4/1/11 – Phase Diagrams and Heat Quiz HW: Standards Practice
What is the empirical formula of a compound that has a carbon-to-hydrogen ratio of 2 to 6?
(1) CH3 (2) C2H6 (3) C3H (4) C6H2
Which statement describes how an atom in the ground state becomes excited?
(1) The atom absorbs energy, and one or more electrons move to a higher electron shell.
(2) The atom absorbs energy, and one or more electrons move to a lower electron shell.
(3) The atom releases energy, and one or more electrons move to a higher electron shell.
(4) The atom releases energy, and one or more electrons move to a lower electron shell.
An element that has a low first ionization energy and good conductivity of heat and electricity is classified as a
(1) metal (2) metalloid (3) nonmetal (4) noble gas
Which salt is produced when sulfuric acid and calcium hydroxide react completely?
(1) CaH2 (2) CaO (3) CaS (4) CaSO4
Which radioisotope is used to treat thyroid disorders?
(1) Co-60 (2) I-131 (3) C-14 (4) U-238