Question

How will the boiling point of a liter of water containing 1 mole of sodium chloride (NaCl) compare with that of a liter of water containing 1 mole of calcium chloride (CaCl2)? Explain your answer

Answer 1

@aaronq

Answer 2

@iPwnBunnies

Answer 3

what do you know about colligative properties and boiling point elevation?

Answer 4

some stuff, not a lot

Answer 5

i know like molarity molality and percent by mass, and such...

Answer 6

so essentially colligative properties are properties that arise from non-volatile solutes and these aren't dependent on the identity of these.

the more particles that are present in a solution will have a greater the effect.

SO, this question asks you, in other words: "Which of these 2 substances create more particles (e.g. ions) when introduced into water"?

The more particles = higher boiling elevation

Answer 7

oh ok

Answer 8

let me clarify "and these aren't dependent on the identity of these."

The properties arent dependent on what the solute is, just how much of it there is.

Answer 9

ok...

Answer 10

when introduced into solution how many particles (ions) does NaCl dissociate into? what about \(CaCl_2\)?

Answer 11

ummm

Answer 12

do you mean the molar mass?

Answer 13

nope, in other words, what are the ionization equations for the substances listed above?

Answer 14

ummm... ummmm...sorry i have no idea ;(

Answer 15

yeah, sorry

Answer 16

lol you have nothing to be sorry about.

An ionization equation, for example, is:

For LiBr, \(LiBr\rightarrow Li^+ +Br^-\)

lithium bromide dissociates into 2 particles (ions)

Can you try the ones from your problem?

Answer 17

ummm

Answer 18

CaCl2--> Ca + Cl2?

Answer 19

\(CaCl_2 \rightarrow Ca^{2+}+2Cl^-\)

so how many particles did you make?

Answer 20

2?

Answer 21

wait 4

Answer 22

arronq?

Answer 23

3 in total, 2 \(Cl^-\) and 1 \(Ca^{2+}\)

what about NaCl?

Answer 24

NaCl --> Na + Cl?

Answer 25

yup (dont forget the charges)

so taking all the stuff i said earlier about boiling point. Which solution will have a higher boiling point, the one with sodium chloride or the one with calcium chloride?

Answer 26

ummm im guessing the CaCl one?

Answer 27

theres no need to guess. The solution with \(CaCl_2\) will have a higher BP because there are more particles in solution.

Answer 28

oh ok ;) thx