help (1 Viewer)

user18181818

Active Member
Joined
Sep 12, 2023
Messages
228
Gender
Female
HSC
2023
idk if this is even remotely right but i did 100/1.060 to get 94.33...mL which is 0.09433..L
i then found moles of mgso47h20 which is0.05679... and then divided it by the volume to get molarity but it's 0.602...mol/L
and the answer is B i think - i found it on a discord channel
 

SadCeliac

done hsc yay
Joined
Sep 23, 2021
Messages
2,490
Location
Sydney <3
Gender
Male
HSC
2023
if you just do it without including density, you get B, so I think B is incorrect;

molar mass of the whole thingy is 246, so you do 14g/246g/mol = 0.0569mol --> in 100ml
therefore in 1L it's 0.569 mol/L which is B so I think B is wrong

lol that's all I've figured out
 

wizzkids

Well-Known Member
Joined
Jul 13, 2016
Messages
332
Gender
Undisclosed
HSC
1998
The mass of solution is M= 14 g + 100 g = 114 g The density rho ρ of the solution is ρ= 1.060 g/mL so divide M by ρ and you get V=107 mL of solution. The 14 grams of the hydrous MgSO4.7H2O contains n = 0.0568 moles. Therefore divide n by V and you get 0.53 mol/L
 

rainbowspoon1

New Member
Joined
Sep 30, 2023
Messages
20
Gender
Undisclosed
HSC
2023
I got D, 100g + 14g = 114g, divide by 1.060, you get 107.54 which is the volume of the solution. c = n/v, n = 14/120.366, v = 0.10754. therefore c = 1.08 M (3.S.F)
 

rainbowspoon1

New Member
Joined
Sep 30, 2023
Messages
20
Gender
Undisclosed
HSC
2023
I got D, 100g + 14g = 114g, divide by 1.060, you get 107.54 which is the volume of the solution. c = n/v, n = 14/120.366, v = 0.10754. therefore c = 1.08 M (3.S.F)
oops the person who got 0.53 is correct, i didnt include the h20 in the molar mass
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top