Chem 221 Practice Test Questions And Answers All Correct

Confidence Interval which statement is true - Correct Answers98% probability that the answer is contained in said range Solution A is analyzed for iron concentration (gives equation) - Correct Answers13.1 ppm Plug in your absorbance and solve Given data of measurements of iron in blood, can anything be rejected - Correct Answers No Use Gibbs on potential outlier G = (Xi - Xmean) / Std What is not a characteristic of a primary standard? - Correct AnswersIt is hygroscopic (means interacts with water vapor above it) A 0.0100 M solution AgNO3 has a concentration of Ag+ ion equivalent to - Correct Answers1080 ppm You get 0.01 M Ag, its in a liter so 0.01 mols, figure out how many grams that is ppm = mg/kg of solvent How many mililiters of concentrate sulfuric acid, which is 96% pure - Correct Answers56 mL Find grams with molar mass and 96% pure, calculate mL from density In a matrix of unknown or ambiguous content, a good approach to determination of an analyte is to use - Correct AnswersStandard addition method If a weak monoprotic acid, HA, is titrated with a strong base what is not true at the half equivalence point? - Correct AnswerspH does not equal 7.0 A buffer with formic acid and sodium formate with HCl added - Correct Answers3.65 set up pH = pka + log (A/HA) and take away from one and add to other Which statement is correct about a determinate error in an analysis - Correct AnswersA determinate error can always be detected and eliminated by performing a blank analysis Determinate = systematic Indeterminate = random (precision) What is the pH at the equivalence point for the titration of 20.00 mL of formic acid with NaOH - Correct Answers7.92 (can solve using general principles) Cr2O7 electron transfer - Correct Answers6 electrons Determine by your oxidation states Calculate pH of solid anhydrous Na2HPO4 - Correct Answers7.38 Charge balance equation - Correct AnswersNegatives equal positives Will need to multiply the concentrations by charge value Calculate the voltage of cell AgBr, Ag+, Cd 2+ - Correct Answers-0.511 Which ion is the strongest reducing agent under standard conditions - Correct AnswersTi3+, Ti2+ = -.90 Reduction - Cathode Oxidation - Anode Potentiometric methods involve the measurement of - Correct AnswersPotential difference under equilibrium conditions