Answer:
4.52 mol/kg
Explanation:
Given data:
Mass of lithium fluoride = 22.1 g
Mass of water = 188 g
Molality = ?
Solution:
Molality:
It is the number of moles of solute into kilogram of solvent.
Formula:
Molality = number of moles of solute / kilogram solvent
Mathematical expression:
m = n/kg
Now we will convert the grams of LiF into moles.
Number of moles = mass/ molar mass
Number of moles = 22.1 g/ 26 g/mol
Number of moles = 0.85 mol
Now we will convert the g of water into kg.
Mass of water = 188 g× 1kg/1000 g = 0.188 kg
Now we will put the values in formula.
m = 0.85 mol / 0.188 kg
m = 4.52 mol/kg
Answer:
The answer to the 2nd question is C.giants.
Explanation:
The solution needed is prepared as below
by use of the M1V1 =M2 V2 formula where
M1 = 2.25 L
v2 = 1.0M
M2 = 9.0 M
V2 =? l
make V2 the subject of the formula V2 =M1V1/M2
= 2.25 L x 1.0M/9.0 M = 0. 25 L
therefore the solution need 0.25 L of 9.0M H3PO4 and dilute it a final volume of 2.25 l
