front 1 What is the objective (purpose) of each part of the ANC of antiacid tablets experiment? (2) | back 1 Part A finds the amount of ~1M HCl remaining after a reaction with an antiacid tablet with an unknown ANC. Part B uses an antiacid tablet with a known ANC to determine the concentration of the ~1M HCl solution in a process called standardization. |
front 2 Name and define the specific method used in each part of the ANC of antiacid experiment. (2) | back 2 Back titration in part A: Where the basic thing (the antiacid tablet) is dissolved in an acid and that solution serves as the analyte meanwhile a base is the titrant. Standardization in part B: Where the concentration of a solution (HCl) is found. |
front 3 Why is back titration used specifically for Part A of the ANC of the antiacid experiment? two reasons (2) | back 3 The antiacid tablet dissolves better in acid than water and back titration prevents the base from neutralizing with exposure to air. |
front 4 What two indicators are used in this experiment? List their colour changes. | back 4 Bromocresol green (yellow to blue in basic conditions) and phenolphthalein (clear to pink in basic conditions) |
front 5 The stomach contains an acid similar to what solution? | back 5 0.1M HCl |
front 6 The antiacid tablets will be dissolved in what acidic solution? (be specific about conentration) | back 6 0.1M HCl |
front 7 What do ANC and RO stand for? | back 7 Acid neutralizing capacity, reverse osmosis |
front 8 What is the decomposition equation for carbonic acid? | back 8 H2CO3 (aq)-->H2O(l)+CO2 (g) |
front 9 When you dilute a solution what changes and what is constant? | back 9 The volume changes but the number of moles stays constant. |
front 10 When preforming a dilution does one add the entire amount of solute or solvent to the volumetric flask? | back 10 The entire amount of solute. |
front 11 Describe the steps you would take with a clean new burette until it is charged full of your titrant. (2) | back 11
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front 12 In the manual you are told the HCl is ~1M. Why is it necessary to standardize the solution? | back 12 The HCl must be standardized so we can determine the difference in H+ before and after adding the antiacid tablet, aka. the ANC of the antiacid tablet. |
front 13 Why is it necessary to dilute the stock HCl solution before titrating it with ~0.1M NaOH? | back 13 The HCl was ~1.0M meaning there are roughly 10 times as many HCl moles as ~0.1M NaOH. You would need to add a lot of NaOH to get to the end point thus, diluting the HCl allows you to use less NaOH solution. |
front 14 Define the terms equivalence point and end point. | back 14 Equivalence point: Equal amounts of acid and base, End point: indicator changes colour |
front 15 What are the objectives for the three phases of a synthesis (reaction, workup, characterization) in the multiweek redox titration? | back 15 Reaction: Sythesize a sample of potassium trioxalatoferrate (III) trihydrate Workup: Isolate the potassium trioxalatoferrate (III) trihydrate crystals Characterization: Confirm molarities and concentrations inside sample |
front 16 Name this compound: K3[Fe(C2O4)3]*3H2O | back 16 Potassium trioxalatoferrate (III) trihydrate |
front 17 What is the chemical formula for ferrous oxalate dehydrate and what colour is it? | back 17 FeC2O4*2H2O, mustard yellow |
front 18 Is oxalic acid a liquid or solid under normal lab conditions? | back 18 Solid |
front 19 What colour occurs at the end of the permanganate - oxalate reaction in the multiweek synthesis and redox titration? | back 19 A faint pink (phenolphthalein indicator) |
front 20 Why should potassium permanganate be handled carefully? | back 20 If it gets on clothes or skin it will reduce and leave brown stains. |
front 21 What is the catalyst used in the potassium permanganate - oxalate reaction? | back 21 Mn2+ (Manganous ion) |
front 22 What colour are the crystals of K3[Fe(C2O4)3]*3H2O? | back 22 Radioactive green |
front 23 Why did you analyze the crystals of K3[Fe(C2O4)3]*3H2O? | back 23 To confirm that they have an appropriate amount of each ion. This also confirms their purity. |
front 24 In qualitative analysis of cations which ions are in the silver group (group 1)? (4) | back 24 Ag+, Hg22+, Tl+, Pb2+ |
front 25 In qualitative analysis of cations which ions are in the copper group (group 2)? (5) | back 25 Hg2+, Bi3+, Cu2+, Sn2+, Sn4+ |
front 26 In qualitative analysis of cations which ions are in the zinc-aluminium group (group 3)? (6) | back 26 Zn2+, Fe2+, Fe3+, Ni2+, Cr3+, Al3+ |
front 27 What do group 1 cations precipitate as? | back 27 Chlorides |
front 28 WHat do group 2 cations precipitate as? | back 28 Sulfides |
front 29 What do group 3 cations precipitate as? | back 29 Sulfides and hydroxides |
front 30 Adding what precipitates the group 1 cations? (concentration and species) | back 30 6M HCl |
front 31 Adding what precipitates the group 2 cations? (concentration, species, pH) | back 31 0.1M H2S, pH of 0.5 |
front 32 Adding what precipitates the group 3 cations? Why is further discrimination possible with them? (2 species, concentration for 1, pH) | back 32 NaOH and 0.1M H2S and a pH of 9. NiS and ZnS won't redissolve if layered with 10-2 M acid. |
front 33 All the group 1 cations precipitate as what colour? | back 33 White |
front 34 In the confirmatory test for lead what colour are you looking for? What colour might be masking it? | back 34 Yellow, orange |
front 35 In the confirmatory test for silver and mercury what differences in reactions are you looking for? | back 35 Most or all the precipitate dissolving (AgCl) or the precipitate becoming black or grey (Hg2 2+) with the addition of 6M NH4OH. |
front 36 In the confirmatory test for mercury (Hg2+, not Hg2 2+ this time) what are you looking for when you immerse a piece of copper wire in your solution? | back 36 A shiny deposit of mercury on wire as it is reduced |
front 37 In the confirmatory test for bismuth what colour are you looking for when adding the sodium stannite to reduce the bismuth? | back 37 jet black |
front 38 In the confirmatory tests for copper what are the two possible indicators of a positive test? | back 38 The presence of a dark precipitate in a heated solution or the appearance of a maroon precipitate. |
front 39 What colour are you looking for in the confirmatory test for Cadmium? | back 39 Yellow |
front 40 In the confirmatory test for tin what colours are you looking for in a precipitate? | back 40 Yellowish or brownish |
front 41 In the confirmatory test for nickel what colour are you looking for upon the addition of acid? | back 41 Red |
front 42 In the confirmatory test for zinc what colour precipitate are you looking for? | back 42 White or white/greyish |
front 43 In the confirmatory test for iron what colour of precipitate are you looking for upon the introduction of HCl, water and KSCN? | back 43 Dark red |
front 44 In the confirmatory test for aluminium what colour precipitate are you looking for upon the adjustment of the pH to basic? | back 44 White |
front 45 In the confirmatory test for chromium what colour are you looking for upon the addition of H2O2? | back 45 Dark blue |
front 46 In the synthesis of Aspirin what are the objectives of the three phases? | back 46 Reaction: Synthesize aspirin from salicylic acid and acetic anhydride in the presence of a catalyst Workup and purification: Isolate and purify it via cold water washes and recrystalization Characterization: identify purity of Aspirin with infrared spectroscopy and NMR. |
front 47 What are the three relevant functional groups in acetylsalicylic acid? | back 47 Carboxylic acid, Ester, Arene |
front 48 Acetic anhydride reacts with water to form what product? | back 48 Acetic acid (C2H3OOH) |
front 49 Write a balanced equation for the reaction between acetic anhydride with water. | back 49 C4H6O3 (aq)+H2O(l)->2C2H4O2 (aq) |
front 50 Identify the functional groups of salicylic acid. | back 50 Carboxylic acid and alcohol |
front 51 Why is it necessary to provide detailed structures of the reactants and products in the synthesis of aspirin and not just the molecular formulae for a balanced equation? | back 51 Because the chemical formulae can be configured into many different molecules, all with their own properties. |
front 52 If synthesis of Aspirin failed what would you expect to see in the infrared spectroscopy and the NMR? | back 52 Failure would see a greater number of double bonds in salicylic acid than aspirin and there would be no esters present in the NMR as they are only present in aspirin but not any other reactants or products. |
front 53 What is the catalyst in the synthesis of ASA? | back 53 H3PO4 |