Question

Can anyone help me answer this!?!?!?....Also its finding molarity not moles.

Caluclate how many grams of solid Mg(NO3)2 and Sr(NO3)2 to dissolve in water to make your solutions. Specifically,write out the calculations to prepare 100.0ml of 0.1000M Mg(NO3)2 and 100.0 ml of 0.1000M Sr(NO3)2. --The Mg(NO3)2 supplied comes in the form of Mg(NO3)2 6H2O, use the formula weight 256.4 grams per mole in the calculation for Mg(NO3)2.

Answer 1

u der??

Answer 2

yes i am here :)

Answer 3

i can help u too calculate as the que solution is lenghty i ll tell u what to do first acc. to dat u will do is it ok den we will cross chck our ans??

Answer 4

okay that sounds wonderful! Thank you so much!

Answer 5

have u written ur equation of reaction by balancing both sides

Answer 6

no i am not sure how to do that...This pretty new to me...i am sorry

Answer 7

its ok jusst tell me we have to find weight of both ubtance and molarity of equation rit

Answer 8

ok firt we will calculate mass of mg(mg No3)2
formula
mass/mw=v/22.4

Answer 9

as mw=256.4
mass??
volume=1oo/1000 litre

Answer 10

kelly r u der??

Answer 11

yes i am writing this as well...i am following

Answer 12

ok calculate it it must be approx=25.64 gram

Answer 13

yes i got that too

Answer 14

nw apply same formula for nxt compund u will get its mass

Answer 15

as Sr(NO3)2=mw=160

Answer 16

okay hold on please

Answer 17

i came up with 241.6..i am not sure what i did wrong

Answer 18

sorry listen in first compound i forgot to divide it by 22.4 so the ans of mg(NO3)2=1.15gm
and the ans of Sr(NO3)2 is 0.75 gm

Answer 19

for Sr(NO3)2
mw=160
v=100/1000
so ,
m/mw=v/22.4
m=vxmw/22.4
m=100x 160/22.4x 1000
m=0.75 gram

Answer 20

you got it??

Answer 21

okay yes i got it, thanks..and this to find the mass of the compound right?

Answer 22

yess
luk n=m/mw ................(1)
n=v (in litre)/22.4............(2)
from (1) and (2) we get
m/mw=v/22.4

Answer 23

nw for calculating molarity we have to write equation
Mg(NO3)2 + Sr(NO3)2-------> Mg(NO3)2 + 6H20

Answer 24

Mg(NO3)2 + Sr(NO3)2-------> Mg(NO3)2 + 6H20 +Sr

Answer 25

jusst a doubt Mg(NO3)2, Sr(NO3)2 they are solid??

Answer 26

yes they are solid

Answer 27

which equation is the one you are using?

Answer 28

the second one and for molarity we use mole in normality rit??

Answer 29

moles= molarity x valency factor
=normality
= o.1000x 2

Answer 30

okay, where did you get the 2?

Answer 31

moarity=normality/volume
as by above calculation u ll get normality and volume is 100/1000

Answer 32

luk for valency factor calculate the charge present on Mg in Mg(NO3)2
by cross multiplication we get dis

Answer 33

Okay I see, that makes sense

Answer 34

now for molarity jut use d abv formula u ll get approx= 2

Answer 35

as u also know MG i found in 2nd group so it has +2 charge
or you heard o many times dat valency depend on the group num.

Answer 36

your ques is finish any more doubt ??

Answer 37

i am sorry heena, is there a way you can write this out like you did with the attachment you sent me...i am getting confused.

Answer 38

ok in cross multiplication the chare get opposite like on NO3 it has -1 charge which goes to Mg and Mg has +2 charge which goes to NO3
o in compound we will write it like Mg(NO3)2

Answer 39

yes i understand that...i am just lost when you are talking about morality.

Answer 40

lolz.. its molarity ok no doubts now so solve it nd get ur ans bye..