chemistry

  1. L

    standard cell potential questions

    1. Cr(s) + AlCl3(aq) = CrCl3 + Al(s) 2. 2AgNO3(aq)n+ 2H2O(aq) = 2Ag (s) +HNO3(aq) +O2 3. Will the mass increase of the cathode be equal to the mass decrease of the anode in a galvanic cell?
  2. P

    Chemistry unit lab problem

    Hi everyone, Wondering if someone could help me with this lab problem. I can't get my head around it. NaOH= 40,00g/mol p = 2,10 g/cm3 I want 100 ml aq with 0,400 mol/kg How do I solve this? Thanks in advance:)
  3. I

    Hello, Chemistry Forum!

    Hi all, My name is Ivan and I just joined this forum. I am thrilled to read the questions and responses and learn the beautiful science of chemistry. Maybe when I become familiar with chemistry, I'll post up responses to help people out on the forum. I myself attend an arts school and I am...
  4. S

    Phase equilibria, Physical Chemistry

    The transition Sn(s, gray) ⇌ Sn(s, white) is in equilibrium at 18 °C and 1 atm pressure. If ∆S = 8.8 11K mol for the transition at 18 °C and if the densities are 5.75 g/cm3 for gray tin and 7.28 g/cm3 for white tin, calculate the transi- tion temperature under 100 atm pressure .
  5. S

    Phase equilibria, Physical Chemistry

    At 25°C we have for rhombic sulfur: ΔfG°= 0; S° = 31.88 ± 0.17 J /K/ mol ; and for monoclinic sulfur: ΔfG°=63 J/mol; S°= 32.55 ± 0.25 J/K/mol. Assuming that the entropies do not vary with temperature, sketch the value of 'μ' versus T for the two forms of sulfur. From the data determine the...
  6. S

    Phase equilibria, Physical Chemistry

    At 25°C we have for rhombic sulfur: ΔfG°= 0; S° = 31.88 ± 0.17 J /K/ mol ; and for monoclinic sulfur: ΔfG°=63 J/mol; S°= 32.55 ± 0.25 J/K/mol. Assuming that the entropies do not vary with temperature, sketch the value of 'μ' versus T for the two forms of sulfur. From the data determine the...
  7. M

    Help chemistry lab!!

    Hi We did a chemistry lab and have some questions after to submit and I’m really stuck and baffled one a few of them so I’d really appreciate some help and guidance. 5.Is the 2-nitrobenzaldehyde used in this experiment an example of an ortho or para substituted benzene molecule? What does this...
  8. M

    Help with chemistry lab!

    Hi We did a chemistry lab and have some questions after to submit and I’m really stuck and baffled one a few of them so I’d really appreciate some help and guidance. 5.Is the 2-nitrobenzaldehyde used in this experiment an example of an ortho or para substituted benzene molecule? What does this...
  9. K

    Colloid chemistry

    "Calculate how much surfactant is required to reach the CMC in the water phase in the presence of 100 g of oil per litre of the aqueous phase as oil droplets with radius 200 nm. The density of the oil is 0.90 gcm-3. The molar mass of the surfactant is 250gmol-1" I have no clue how to go around...
  10. R

    Challenging and fun chemistry idea from a novice!

    Howdy folks I don't know anything about chemistry and this seemed like a good place to learn. I had an interesting idea that I'm thinking of turning into a private project or small business, but it has chemistry aspects that I'm unfamiliar with so I'm hoping y'all can educate me. I appreciate...
  11. C

    Organic chemistry reaction scheme

    Can someone help me with this reaction schemes?
  12. L

    Analytical chemistry

    Hi, I was wondering if someone could help me How do you calculate the mass needed to make 1ppm zinc from 10%zinc neodeconate in xylene The 1ppm zinc will be needed to make a standard in a total volume of 20mls. Please Can you explain calculations.thanks, Laura
  13. P

    Walsh Diagrams or general chemistry diagram construction applications

    Hey all: I'm a Master's student working on a computational chemistry thesis. Up to this point, for all of my course work I've gotten away with using simple excell graphs for most of my diagrams or figures but now that I'm assembling my thesis I would like to have some nicer figures that look...
  14. E

    Three weeks ago, we lost our chemistry thirty teacher. Our new teacher is not extreme

    We were hoping to find help with this question: What is the final temperature of water if 2.10 grams of methane is burned (molar enthalpy change -802.5kJ/mol) to heat up 400grams of water that is initially at 22.0 degrees celsius? Earlier in our notes it says while using n(delta)Hm =...
  15. F

    What is organic and inorganic chemistry

    Hello What is difference between organic and inorganic chemistry
  16. R

    Hi im new and have a few chemistry questions

    Why are the following stuctures known as hydrocarbons? (CH3-CH3) (CH2=CH2) (CH2=CH-CH3) (CH2=CH-CH2-CH3) What is compound CH3-CH3 and why is it saturated? Many thanks in advance
  17. I

    How to convert from mol% to wt%?

    so the concentration of molecule A is 0.5% mol. The rest of the molecules are water. This is calculated by (number of molecules of A / total number of molecules) x 100 More specifically, this is [20 / (20 + 3980)] x 100 We are given that the molecular weight of A is 136 g/mol. I have no idea...
  18. S

    Organic chemistry: make C9H10O from CH4

    Hello! I need some help making C9H10O from CH4. Can you, please, help me and explain it to me? Thanks in advance and have a nice day! :)
  19. C

    Tasks

    Determine how much 15% potassium hydroxide solution with a density of 1.13 g / ml is required to completely neutralize 20 ml of 10% hydrochloric acid with a density of 1.05 g / ml. 2. Determine how much magnesium can be completely dissolved in 20 ml of a 10% solution of sulfuric acid with a...
  20. S

    Physical chemistry problem

    The composition of vapour over a binary ideal solution is determined by the composition of the liquid. If Xa and Ya are the mole fraction of A in the liquid and the vapour respectively, find the value of Xa for which Ya-Xa has a maximum. What is the value of the pressure at this composition in...