Choose Your Category Potential Energy Graph Reaction Rates K eq and K sp Le Châtelier's Principle Definitions Round Two

Potential Energy Graph Where is the location on the activated complex on this graph? Back The Answer is the top of the hump.

Potential Energy Graph What is the energy of the products? The Answer is 100 J. Back

Potential Energy Graph What is the energy needed to break the chemical bonds? The Answer is 100 J. Back

Potential Energy Graph What is the net energy of this reaction? The answer is -200 J Back

Daily Double

Reaction Rates Calcium carbonate was placed in a flask on a balance, and dilute hydrochloric acid was added. Carbon dioxide that was produced escaped from the flask. The total mass of the flask and its contents was recorded every 10 seconds. The diagram to the right shows a plot of the results. Between which two times shown was the reaction the fastest? The Answer is 0-10 seconds. Back

Reaction Rates At equilibrium, the forward reaction rate is _____________ to the reverse reaction rate. The Answer is equal Back

Reaction Rates The role of a catalyst is to affect ________________. The Answer is activation energy. Back

Daily Double

Reaction Rates Name three factors that can influence the rate of a reaction. The Answer is any three of the following: concentration of the reactants temperature surface area pressure catalysts Back

K eq and K sp – 100 What is k sp for the dissociation of NaCl in water? NaCl (s) + H 2 O (l)  Na + (aq) + Cl - (aq) The Answer is [Na + ][Cl - ] Back

K eq and K sp – 200 What is the equilibrium expression (Keq) for the following reaction? CaCO 3 (s) + 2H 3 O + (aq)  Ca 2+ (aq) + CO 2 (g) + 3H 2 O(l) The Answer is K eq =[Ca 2+ ][CO 2 ] [H 3 O + ] 2 Back

Random Points 100 Points

K eq and K sp – 300 A very low value of the equilibrium constant for a reaction can indicate that A) products are favored B) equilibrium is reached slowly C) Reactants are favored D) equilibrium is reached quickly The Answer is C. Back

K eq and K sp – 400 What is the solubility in mol/L of silver iodide, AgI? Its K sp value is 8.3 x and the equation is AgI (s)  Ag +1 (aq) + I -1 (aq). The Answer is 9.11 x Back

Le Châtelier's Principle [Ni(H 2 O) 6 ] NH 3  [Ni(NH 3 ) 6 ] H 2 O (endothermic) greenblue-violet What color would you expect the above solution to be if NH 3 is added? (Green, blue-violet or no change) The Answer is blue-violet Back

Le Châtelier's Principle [Ni(H 2 O) 6 ] NH 3  [Ni(NH 3 ) 6 ] H 2 O (endothermic) greenblue-violet What color would you expect the above solution to be if water is removed? (Green, blue-violet or no change) The Answer is blue-violet. Back

Random Points 300 Points

[Ni(H 2 O) 6 ] NH 3  [Ni(NH 3 ) 6 ] H 2 O (endothermic) greenblue-violet What color would you expect the above solution to be if NaBr is added? (Green, blue-violet or no change) Le Châtelier's Principle The Answer is no change. Back

The Answer is blue-violet Le Châtelier's Principle [Ni(H 2 O) 6 ] NH 3  [Ni(NH 3 ) 6 ] H 2 O (endothermic) greenblue-violet What color would you expect the above solution to be if the solution is heated? (Green, blue- violet or no change) Back

Definitions – 100 The Answer is reversible reaction. A chemical reaction in which the products re-form the original reactants Back

Random Points 500 Points

Definitions – 200 A state of balance in which the rate of a forward reaction equals the rate of the reverse reaction and the concentrations of substances do not change The Answer is equilibrium. Back

Definitions – 300 A type of protein that speeds up metabolic reactions in plant and animals without being permanently changed or destroyed The Answer is an enzyme. Back

Definitions – 400 The minimum amount of energy required to start a chemical reaction. The Answer is activation energy. Back

Choose Your Category PropertiesIdentify the Acid or Base pHK w and K a TitrationsDefinitions The Final Question

Properties Acids taste __________________. Back The Answer is sour, or any word that means sour.

Properties If a base was touched, it would feel ____________________. Back The Answer is slippery.

Properties Strong acids are ______________ electrolytes. Back The Answer is strong.

Properties Strong acids ______________ ionize when added to water. Back The Answer is completely.

Identify the Acid or Base Whose definition of acids and bases emphasizes the role of protons? Back The Answer is Brønsted-Lowry

Random Points 300 Points

Identify the Acid or Base An Arrhenius Acid increases the _____________ concentration. Back The Answer is hydronium.

Identify the Acid or Base In the reaction H 3 PO 4 + H 2 O  H 3 O + + H 2 PO 4 -, the ion H 2 PO 4 - acts as a(n) ___________________. Back The Answer is base.

Daily Double

Identify the Acid or Base Label the acid, base, conjugate acid, and conjugate base in the equation: HCl(g) + H 2 O(l)  H 3 O + (aq) + Cl - (aq) Back acid baseconj acid conj base

pH What is the pH of a neutral solution at 25°C? Back The Answer is 7.

Random Points 500 Points

pH The pH of a solution is 8. What is its H 3 O + concentration? Back The Answer is 1x 10 -8

pH What is the pH of a 1 x M KOH solution? Back The Answer is 11.

pH What is the pH of a M KOH solution? Back The Answer is 11.9.

K w and K a – 100 What is the value of the self-ionization constant of water? Back The Answer is 1 x

K w and K a – 200 What is the equilibrium expression (K w ) for the self-ionization of water? Back The Answer is K w =[OH - ][H 3 O + ]

K w and K a – 300 What is the acid-ionization constant, Ka, for the ionization of acetic acid, shown in the reaction CH 3 COOH(aq) + H 2 O(l)  H 3 O + (aq) + CH 3 COO – (aq)? Back The Answer is [H 3 O + ][CH 3 COO - ]/[CH 3 COOH]

Daily Double

K w and K a – 400 A M sample of carbonic acid, H 2 CO 3, has a measured hydronium ion concentration of 5.36 x 10 –3 M. Calculate the acid-ionization constant of carbonic acid. The equilibrium equation is H 2 CO 3 (aq) _ + H 2 O (l)  H 3 O + (aq) + HCO 3 - (aq) Back The Answer is 3.4 x 10 -5

Titrations During a titration the volume of the titrant is measured with a(n) ____________________. Back The Answer is buret or burette

Titrations What unknown quantity can be calculated after performing a titration? Back The Answer is concentration or volume.

Titrations During a titration, the indicator _________________________ is used to study neutralizations of weak acids with strong bases. Back The Answer is phenolphthalein.

Daily Double

The Answer is Titrations Calculate the molarity of a Ba(OH) 2 solution if 1950 mL is completely titrated by 261 mL of M HNO 3. Ba(OH) 2 + 2HNO 3  Ba(NO 3 ) 2 + 2H 2 O Back

Definitions – 100 Back The Answer is transition range. The pH range over which an indicator changes color is its _________ _________.

Definitions – 200 A(n) ____________________ solution resists changes in pH. Back The Answer is buffer.

Random Points 200 Points

Definitions – 300 A _____________ ________ is the species that remains after an acid has given up a proton. Back The Answer is conjugate base.

Definitions – 400 Water is an example of a(n) _______________________, something that can act as a base or an acid. Back The Answer is amphoteric species

The Final Question The final question has to deal with: »Indicators Make your wager and hand it to the teacher

What indicator(s) would be the best choice for a titration with an equivalence point at a pH of 7.0? What color would the solution start? What color would the solution be after the titration is over? IndicatorAcid Color pH Transition Range Base Color Thymol Bluered yellow Bromphenol blueyellow blue Bromcresol greenyellow blue Bromthymol blueyellow blue Phenol Redyellow red Alizarin yellowyellow red

And the Answer is: The Answer is Bromthymol blue, yellow, blue and Phenol Red, yellow, red