hey
for this questions write an equation that shows hso4- acting as base in water. Would it be. Thank you

h2so4 + h20 = hso4- + h30+

    chemistry1111
    You’re showing H2SO4 acting as an acid, not HSO4- acting as a base. Remember that bases grab H+ i.e. they neutralise (remove) H3O+ instead of making more H3O+

      hamna_fa
      Hi!

      Edit: I'm completely wrong... Mybad! See Will

      Presuming the standard solution is used to make the titrant/aliquot; here's my understanding!

      - This would mean that the concentration would have been artificially decreased (as the titrant would be diluted).
      - This would mean there would be an overestimation of aliquot added.

      • Meaning the concentration measurement would be greater than the real value.

      Hope this helps!

          Is the volumetric flask not supposed to be rinsed with only deionsied water?
          It says the "accuracy of the standard solution", so I'm assuming the volumetric flask is used to make the standard solution. If so, it should be washed with water regardless, as water is added to make these, and it is filled up to a certain point in the beaker.

          The only thing that is washed with the solution which will go in it is the burette and the pipette, right?

            Will
            This is correct. You're filling the volumetric flask with water anyways so it doesn't matter if there's some residual water left. The other glassware you wash with distilled water is the conical flask

              hamna_fa
              It's OK since you're going to add more water to the Na2CO3 in the volumetric flask anyways

                Christ It disrupts the H bonding in 2˚ and 3˚ structures of proteins with its hydroxyl group

                  Greetings,

                  For mass spectroscopy, do we need to know how to write the equation which produces the parent molecular ions and base peaks?
                  I saw it on a VCAA 2010 exam, but not sure if it's within the scope of the new study design.
                  And if so, could anyone provide an example of how you would write it?

                  Thanks,

                  Your Lord

                    Lord I don't think you need to in the new SD. If you're curious, it's M + e- ---> M+ + 2e-. Some people choose to show it with a radical ie M+. but I don't

                      5 days later

                      Hey guys I have a question.

                      So I'm doing a gravimetric analysis task tmr where we have to look at the % of sulphate in fertilizer and compare it to the manufacturer's claim.

                      One of the steps in the experiment is to grind the fertilizer and then mix it with both HCl and distilled water. Then we boil and add barium chloride to form a precipitate.

                      I was just wondering what the role of the HCl was.

                        sasushi
                        A lot of times in fertilisers they also have phosphate in there. Following the solubility rules, barium phosphate is also very insoluble in water, so when you add BaCl2 to the fertiliser which may contain phosphate some Ba2(PO4)3 precipitate may form and you might erroneously include it in the mass of BaSO4 precipitate, which overestimates the sulfate content of the fertiliser. Ba2(PO4)3 is soluble in HCl so adding HCl will prevent it from precipitating such that the final precipitate is exclusively BaSO4

                            hamna_fa
                            You have volume and concentration of the Na2S solution so you want to convert that to mol and then you’d use molar ratios to calculate n(CdS) and hence m(CdS)

                            Cd(NO3)2 in excess = Na2S is limiting which means the amount of Na2S present (not Cd(NO3)2) is important to know if you want to calculate how much CdS precipitate is produced

                              Hi Billzene!

                              For VCE purposes; do we need to know how to number carbons in a cyclic molecule?

                              Eg. For determining if a monosaccharide is alpha or beta?

                              Thanks in advance 🙏

                              • G

                                God you need to recognise the structures of alpha/beta anomers of glucose, but you don’t need to know how to name cyclical compounds except maybe benzene

                                • Will likes this.
                                • God replied to this.

                                    Hii everyone!
                                    I am so confused...
                                    The answer says 5-bromo-2-chloro-4-ethylhexane
                                    but can't it also be
                                    2-bromo-5-chloro-3-ethylhexane
                                    then which one do you prefer?
                                    Please help Thank you!!!

                                    Ps. I am not sure how to attach the photo

                                    • God replied to this.

                                      PizzaMaster
                                      Yeah I see what you mean....

                                      I just tried plugging it into mol-view; which breaks whenever I try to render it / view it's name. Fair chance this molecule doesn't exist... but then again - its chemistry... So who knows.

                                      Maybe Billzene?

                                        14 days later

                                        What is the accepted equation for alkene hydration?

                                        Is it done with H2 gas? I've read that it is done with steam(H2O) but my textbook says H2(g).
                                        What does VCAA say?

                                          Will
                                          My Edrolo textbook (and what my teacher has taught) says that alkene hydration involves H2O, requiring phosphoric acid and heat as a catalyst (therefore, I'm assuming H2O would be steam due to the heat?). H2(g) is involved in alkene hydrogenation, and needs a metal catalyst (e.g. Ni). Just remember that when you hydrate, you're drinking water, so alkene hydration must involve water (and hydrogenation involves H2(g)). I'm not 100% sure if I'm correct, but that's what I've been taught.

                                              Hydrogenation: Alkene + H2 (g) → Alkane: Ni(s)
                                              Hydration: Alkene + H2O(g) → Alcohol: H3PO4 (H2SO4 also accepted)

                                              a month later

                                              hi all! i just have a couple quick questions regarding calculations... sorry if these have already been asked!

                                              when you are calculating the specific heat capacity of water, does vcaa expect us to convert mL to grams (as in multiply by 0.997)?

                                              also when finding the percentage atom economy, do you have to take into account the coefficients in the given equation? like if it's 2H2O would you use 2x18 as the molar mass?

                                              sorry if these don't make sense, I've just noticed a slight difference in given solutions across different papers
                                              thanks in advance!!

                                                bw304
                                                Hello

                                                Q1/ When you are doing calculations involving the equation q=mcΔT, only convert mL to grams if it specifically tells you that the experimental conditions are SLC because the density of water varies with temperature. If conditions are non SLC, then you can just assume mL of water = g of water.

                                                Q2/ Atom Economy takes into account the stoichiometric ratios of the reaction.
                                                SCENARIO
                                                Observe the reaction below, where C is the desired product.
                                                Reaction 1) 5A+5B → C +9D
                                                Reaction 2) 5A+5B→9C+D
                                                It would "make sense" that Reaction 2 has a higher atom economy because greater proportion of the reactants are being converted to the desired product (9C) as compared to Reaction 1, which has a lower atom economy as only 1 C is being produced.

                                                Hope this makes sense 😀

                                                  Also just randomly, Remember:

                                                  For the purpose of the VCE Chemistry Study Design, whole numbers will have the same significant figures as number of digits, for example 400 has three significant figures while 400.0 has four.

                                                  This keeps tricking me - lol 😆

                                                  Hey all,
                                                  Quick qs.
                                                  Why is can this not be A wouldnt it still force a forward reaction in both reactions.

                                                  Dissolved carbon dioxide, CO2, can react with water, H2O, to form carbonic acid, H2CO3.
                                                  H2CO3 can also react with H2O to form bicarbonate ions, HCO3
                                                  –, and hydronium ions, H3O+.
                                                  CO2(aq) + H2O(l) ⇌ H2CO3(aq)
                                                  H2CO3(aq) + H2O(l) ⇌ HCO3
                                                  –(aq) + H3O+(aq)
                                                  A beaker that contains 2 L of deionised water is placed in a room and left overnight so that these two
                                                  reactions reach equilibrium. In the morning one change is made to the system.
                                                  Which one of the following changes is most likely to result in an increase in the concentration of H3O+ ions?
                                                  A. Dilute the solution.
                                                  B. Bubble in more CO2 gas.
                                                  C. Add a few drops of phenolphthalein indicator.
                                                  D. Add a few drops of 0.1 M sodium hydroxide, NaOH, solution.

                                                  Correct answer is B

                                                    While adding water is technically adding a reactant, and should effect the equilibrium, as it is water all it will do is dilute both sides equally, meaning that the concentrations of each are reduced proportionally to each other. Water is not used to determine the equilibrium constant(Kc), so I believe we ignore it when determining which way equilibriums will shift.

                                                    I'd appreciate it if other people could confirm

                                                    N1ck3lGall1um The effect of dilution will be greater than that of any H3O+ produced. However adding CO2 will prompt the system to use it up which favours the side with H+. That's why if you breathe in a paper bag for too long, your blood pH will drop (this is called respiratory acidosis)

                                                      Hey all, thanx for your help 😀, but I got another one.

                                                      When the battery is fully charged, it has a lead, Pb, anode, a lead(IV) oxide, PbO2, cathode and
                                                      a sulfuric acid, H2SO4, electrolyte. When fully discharged, the two electrodes are both coated in
                                                      lead(II) sulfate, PbSO4.
                                                      Pb(s)(anode), H2SO4(aq)(electrolyte) and lead(IV) oxide PbO2(s) (cathode)
                                                      a. i. Write the oxidation reaction, including states, that occurs during discharge:
                                                      Pb(s) + H2SO4(aq)  PbSO4(s) + 2H(aq) + 2e–
                                                      Pb(s) + SO42–(aq)  PbSO4(s) + 2e–
                                                      Can someone please explain why H2SO4 is involved during oxidation .
                                                      Cant Pb just oxidise by itself to produce Pb2+

                                                        Hey guys, 1&2 chemistry here, do you have any tips for practical investigation posters? I’m not sure where I’m going with my discussion.
                                                        My poster is on a titration to find the concentration of CaCO3 (water hardness) and an evaporation to find TDS, I didn’t get any meaningful results as I didn’t understand how to perform a titration so my results section is suffering too.

                                                          Emmy I don't understand which technique(s) you're using, it seems like you're using both volumetric and gravimetric techniques?

                                                          • Emmy replied to this.

                                                              Billzene yes, the experiment had two parts aiming to analyse water quality

                                                                  Emmy what kind of results are you getting? Can you reason what may have caused them in your discussion?

                                                                    hey guys! just a question...
                                                                    when drawing a sequence of amino acids, can you draw each amino acid similar to how it is presented in the data book, or does vcaa expect you to show all bonds? like instead of NH2 doing H-N-H, etc?
                                                                    tia!!