Answer:
correct option is (a)
The solution would be using this: C6H5COOH = H+ + C6H5COO Ka = 6.5 x 10^-5 = (H+)(C6H5COO-) over
(C6H5COOH)
Let X = moles per liter (H+) and also = moles per liter (C6H5COO-)
Ka = 6.5 x 10^-5 = (X)(X) over .350 molar = acid solution 6.5 x 10^-5 = X^2 over .350
X^2 = 6.5 x 10^-5 times .350 which = 2.275 x 10^-5
x = V2.275 x 10^-5
X = 1.5083 x 10^-5 moles per liter H+
pH = -log(H+) = -log 1.5083 x 10^-5 which
= 4.6215
Answer:
D) The water will freeze into cubes again.
Explanation:
When the ice cubes is left on a counter, it will melt as the forces that make its molecules stick together is broken.
If that tray is put back in the freezer again, the water will freeze into cubes again.
When water freezes, the molecules slow down and settle into its place, arranging in a regular shape that can be appeared as crystals (ice cubes).
Hey there!:
ΔTf = Kf * m
Molar mass glucose = 180 g/mol
number of moles glucose:
n = mass of solute / molar mass
n = 21.5 / 180
n = 0.119 moles glucose
Amount of solvent in kg = 255/1000 = 0.255 Kg
Molality = number of moles / solvent
m = 0.119 / 0.255
m = 0.466 moles/kg
Kf for water = - 1.86 ºC/*m
Therefore:
ΔTf = Kf * m
ΔTf = (-1,86) * 0.466
ΔTf = -0.86676 ºC
hope this helps!
I would say
change: Temp
Measure: Mass
Control: Volume
