Epinephrine's noob chemistry question

[REBORN]

pg number, q number? I have the same book - I'm assuming it's from c11....

[Lasercookie]

I got 7.11 * 10^-3 as well.

Chapter 11, 12a? I'll check what the Heinemann worked solutions did.

Edit:

This is what Heinemann did:

n(CaCl2) =   m/M = 1.223/75.5 = 0.0162 mole
c(CaCl2) = n/V = 0.0162/1.55  = 0.0105 M

I'm positive they calculated that Molar Mass of CaCl₂ wrong.

[epinephrine]

yup it is from chapter 11 pg 215 question 12. a

[pi]

I got the same answer...who said it was wrong?

Units?

Nah, your figure is correct, answers must be wrong

[tony3272]

Found the question. Heinemann 1 Ch 11 Q12. In the worked solutions they use the wrong molar mass for CaCl2. Your answer is correct.

[REBORN]

Oh man don't ever use the worked sols. They are absolutely shocking...wait till you get to pH questions (c14).

Check the back of the book...they give it right as 0.00711M.

(my v. is ENHANCED, maybe the old edition has it wrong on the back of the book too...)

[epinephrine]

ok cool man there are so many incorrect solutions in that book, anyways what about question 13  same page could you guys confirm if my answers are correct?

a. 4M
b. 0.075 M
c. .475 M
d. 2.76 g/L

[Lasercookie]

Oh man don't ever use the worked sols. They are absolutely shocking...wait till you get to pH questions (c14).

Check the back of the book...they give it right as 0.00711M.

(my v. is ENHANCED, maybe the old edition has it wrong on the back of the book too...)

Yeah old edition has the wrong answer at the back of the book.

[tony3272]

ok cool man there are so many incorrect solutions in that book, anyways what about question 13  same page could you guys confirm if my answers are correct?

a. 4M
b. 0.075 M
c. .475 M
d. 2.76 g/L

c. should be 0.025.







the solution is diluted to 100mL, so new concentration is

[REBORN]

ok cool man there are so many incorrect solutions in that book, anyways what about question 13  same page could you guys confirm if my answers are correct?

a. 4M
b. 0.075 M
c. .475 M
d. 2.76 g/L

C is wrong. And (d) is automatically wrong 'cause it's not in M (n/L)

EDIT: BEATEN!! DAMN

[epinephrine]

Oh haha right I used the wrong c1 for part c. But for part d I don't know why it is wrong when I divided by M(molar mass) I still got the same answer of .033 M as in the book but is the concentration that I had in terms of g/L is wrong since the book had their answer as 3.3 g/L or 0.030 M?

[REBORN]

q13 - calculate the 'molar concentration'

your answer to (d) is not even answering the question...do you get what I mean? Molar conc = M = n/L

I uh don't know how to do latex so I'll leave someone else to do the working *cough, lazy*

[epinephrine]

Oh it doesn't say calculate the Molar concentration in my book it just says calculate the concentration. Yeah I think that might be in the enhanced edition but in the old edition it just says calculate concentration.

[REBORN]

Faceplam.

haha, ignore me -.-