chemistry

I am enrolled in analytical chemistry after a 4 year break from any chemistry. I was recently given a problem set and I need some help on the following:

A 0.899g sample containing epsom salt, MgSO4 & 7 H2O, and other non-hydrated materials was dehydrated completely in a stream of hot, dry nitrogen. The resulting air stream was passed through a tube containing the desiccant magnesium perchlorate. The original weight of the desiccant tube was 61.997g and, after the determination, the tube weighed 62.318g. What is the % epsom salt in the sample.

I would appreciate any help. Thanks!

  1. 👍
  2. 👎
  3. 👁
  1. The gain in weight of the perchlorate is the mass of H2O. Convert that to mols by mols = grams/molar mass H2O.
    Convert mols H2O to mols MgSO4.7H2O using the coefficient in the balanced equation below.
    MgSO4.7H2O+ heat ==> MgSO4 + 7 H2O
    mols MgSO4.7H2O = mols H2O x (1 mol MgSO4.7H2O/7H2O). (note how the units that we don't want cancel and leaves the units we want to keep.)
    Convert mols MgSO4.7H2O to grams.
    g = mols x molar mass.
    Finally,
    %MgSO4.7H2O = [mass MgSO4.7H2O/mass sample]*100 = ??
    Post your work if you get stuck.

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. maths

    In a class of 80 students, 53 study Art, 60 study Biology, 36 study Art and Biology, 34 study Art and Chemistry, 6 study Biology only and 18 study Biology but not Chemistry. Illustrate the information on a Venn diagram. Determine

  2. math

    A school has 63 students studying Physics, Chemistry and Biology. 33 study Physics, 25 Chemistry and 26 Biology. 10 study Physics and Chemistry, 9 study Biology and Chemistry while 8 study both Physics and Biology. Equal numbers

  3. Math

    In a class of 100 students, 40 offer Biology and 10 offer Chemistry and Biology .10 offer Physics and Chemistry , and 30 offer Physic and Biology . Each student offer at least one of the three subjects. The number of students who

  4. just wondering...

    what is harder, chemistry or physics? because i've been struggling all year in chemistry and i'm taking physics next year... i have a solid a in alg.2 though... oh yeah, and i want to be a physical therapist. so if i'm not to good

  1. Further maths

    In an examination 31 candidate passed Chemistry,29 passed Physics 3 failed both subjects.lf 50 candidates sat for the examination how many of them passed Chemistry only.

  2. Chemistry

    Calculate the standard free-energy change for the following reaction at 25 C degrees. 2Au^3+(aq)+3Ni(s) 2Au(s)+3Ni^2+(aq) Ni2+(aq) + 2e- -> Ni(s) E=-0.26 Au3+(aq) + 3e- -> Au(s) E=+1.498 G= ? KJ Would it be G=1.758? •Chemistry -

  3. Set

    In a class of 27 student at least one of the student do chemistry and biology offer chemistry while 18 do biology find :those who offer biology only, those who offer chemistry only, those who offer both subject

  4. maths

    in a class of 35 students twice as many study chemistry and study physics half a many study chemistry as study both subjects illustrate it on a venn diagram

  1. Maths

    In a class of 80 students,53 study Art,60 study biology,36 study Art and biology,34 study Art and chemistry,6 study biology but not chemistry.Illustrate the information on a Venn diagram.Determine the number of students who study

  2. statistics

    According to a certain country's department of education 39.6% of 3-year olds are enrolled in day care. What is the probability that a randomly selected 3-year old is enrolled in day care?

  3. math

    In a class of 50 student, 25 offer mathematics, 22 offer physcis, 30 offer chemistry and all the student take at least one of these subjects , 10 offer physics and mathematics, 8 offer chemistry and mathematics , 16 offer physics

  4. Mathematics

    In a class,30 offer Biology,21 offer Chemistry and 22 offer Physics.15 offer Physics and Biology,10 offer Physics and Chemistry and 13 offer Biology and Chemistry.2 offer Physics only,3 offer Chemistry only and 7 offer Biology

You can view more similar questions or ask a new question.