1. K

    Calculating atmospheric SO2 with pH and K values given

    Hello, I am currently doing a take home exam and I'm completely stuck on a problem. I've been scouring the internet and my textbook for hours upon and and I'll be honest - I have no idea how to even attempt this problem. I was hoping someone could at least nudge me in the right direction or tell...
  2. S

    carboxylic acid/koh calculating titration curves

    Hi, I am attempting to calculate various theoretical tittration curves for a strong base weak acid titration: similar to the one in this wiki: I don't have any difficulty calculating the inital ph or the pH at/after the equivalence...
  3. D

    Calculating % analytes in HPLC

    When calculating the % of an analyte with HPLC, the raw material used for making the product has a purity of 79%, but the standard used for analysis has a purity of 75%. In the calculation, is there a factor to correct for the purity of the standard, purity of the raw material, or does there...
  4. T

    Calculating number of moles from Keq

    Hello, I am having trouble with a question on my lab report that is as follows: "Calculate the number of moles of reactants and products in an equilibrium mixture. Complete the ICE table below." I am given the Keq which is 3 and the initial amount of acid and alcohol which are (0.25/V) each...
  5. T

    Calculating potential of a solution

    Hi I'm having some trouble with the following problem: Calculate the potential of a solution made by mixing equal volumes of 0.20M thallium(I)nitrate and 0.20M dibromine in 1M HCl. E°'(Tl3+/Tl+) = 0.77V en E°'(Br2(aq)/2Br-) = 1.087V The answer given is 0.934V This is what I have so far...
  6. S

    calculating volume from w%

    I have a 1% w DMG solution. Now in an analysis I need to use 0.178g DMG. How can I calculate what volume of solution contains that much of DMG? Density of the alcohol is 0.79 g/ml. Is it possible to calculate the vol of the solution from here?
  7. C

    calculating energy with kilojoules? finals in two hours!

    I am not sure what this is formally called so i just called it calculating energy with kilojoules? anyways, i have finals in like two hours and this problem is guaranteed to be on there but i have no idea how to do it! i tried but i am not sure please help thank you.
  8. K

    Calculating PV work done at atmospheric pressure?

    I need some help figuring out this problem. This is the original problem: How much PV work is done in kilojoules for the reaction of 3.74 mol of H2 with 1.87 mol of O2 at atmospheric pressure if the volume change is −23.9L? And we are given this reaction: The reaction between hydrogen and...
  9. B

    Calculating Ksp CHem 12 problem?

    A student determined that exactly 0.0533 g of manganese (ii) fluoride was dissolved in 800 mL water to make a saturated manganese (ii) fluoride solution. What is the Ksp for manganese (ii) fluoride? solubility related to [ions] reacted 0.0553 g MnF2 dissolves/800 mL * 1 mol/ 92.9g * 1 mol...
  10. P

    Please help with calculating limiting reagent?

    I did an experiment in which I added 0.2116 mols acetic anhydride to 0.0222 mols glucose to form 0.0178 mols glucose pentaacetate. I am attempting to calculate the limiting reagent, but I can't balance the equation properly! What I get is: 15 C4H6O3 + -2 C6H12O6 = 3 C16H22O11 How am I...
  11. M

    Calculating Mole Masses, Combustion

    Hello I am stuck with these 5 homework problem that I am unable to solve or set it up, can anyone help me how to get the answer to these? 1) Calculate the number of grams and pounds of CO2 that result from the combustion of 1 gallon of gasoline (we will assume that gasoline is mostly octane...
  12. P

    Help with calculating water ph changes

    I am new and I have no idea if I am in the right forum. I don't know if what I am asking is feasible. I have an aquarium with water that has a high ph (8.4) and I would like to reduce the ph by adding water with a lower ph (6.7). I would like to calculate the average proportion of each...
  13. H

    Calculating amount of NaOH to raise pH of solution

    I need to get a 5 wt% NaCl solution within the pH range of 6.5 - 7.2 to meet specifications for a test. After initial mixing, the pH of the NaCl solution typically measures around 6. I'm assuming that the slight acidity of the solution is due to carbonic acid, from carbon dioxide in the air...
  14. J

    Calculating concentration

    Hi, Im trying to figure out how to answer a sample question for a practice chem exam and i'm have a little trouble. The question is: Having measured the absorbance of several Co(NO3)2 solutions of known concentration, a student plotted the graph above. The student was then given a...
  15. P

    Calculating Kc for equilibrium?

    Given the chemical equilibrium: H2 + ½ S2 ⇌ H2S If the amounts of H2, S2, & H2S at equilibrium are 2, 1 & 3 moles respectively in a 10.0L flask, calculate Kc for the reaction. Write the expression for Kc for the production of 4 moles of H2. ----------------------------- The way I...
  16. N

    Calculating Freezing point

    I am asked to calculate freezing point of a substance at 1x10^4 atm given the following information freezing point at 1 atm densities of the solid and liquid phase (in g/mL) change in entropy per mL melted I am to assume that both solid and liquid are incompressible, and that change in...
  17. S

    Calculating Standard Enthalpy Change

    Hello! :) I have honestly no idea on how to approach this seemingly easy question, can somebody please provide me with some assistance? I'm adding the enthalpy values up and then entering that as the answer (along with numerous other attempts that have been unsuccessful) and I just don't know...
  18. O

    Calculating Moles

    I'm stuck on this question. Assistance would be greatly appreciated! Thank you. The question is: 1 Liter of a 5% glucose (w/v) solution is to be administered intravenously to a patient. How many moles of glucose (C6H12O6) will the patient receive from this IV?
  19. M

    Calculating Ksp

    Hi, I was hoping someone could double check a chemistry answer for me. I am trying to calculate the Ksp of Ag2CrO4. This question is based on an experiment to determine Ksp experimentally. In the experiment the Ksp of silver chromate was calculated using a single displacement reaction between a...
  20. C

    Calculating concentration of Nitric acid

    Can someone help me with a formula? I'm trying to find out the volume percent of a nitric acid solution. If I titrate my solution with 1.0N sodium hydroxide until I reach an end point what is the formula to determine percent of acid given x amount of NAOH used to reach the endpoint. Thanks