In order to have a freezing point of −15.0°c means we need a depression in freezing point to be −15.0°c
we know that depression in freezing point is a colligative property which depends on molality as
depression in freezing point = Kf X molality
Kf = 1.86 °C/m
molality = moles of solute / mass of solvent in Kg
15 = 1.86 °C/m X molality
molality = 8.065
molality = moles of glycerol / mass of water in Kg
moles of glycerol = 8.065 X 928 X 10^-6
moles = 0.00748
moles = mass / molar mass
mass = moles X molar mass = 0.00748 X 92 = 0.688 grams = 688 mg
so this is the minimum mass required
Answer:
the answer is 7 which is the atomic number of nitrogen
Explanation:
Al+Na=24
24/Oxygen (8) =3
3x rounded atomic mass of Ne (3x20) = 60
60+ 20 (# of neutrons in K)=80
80-30 (# of electrons in zinc)= 50
50/25 (the atomic number of Mn)=2
2x9 (number of protons in F)= 18
18+24 (atomic mass of Mg)=42
42/6 (number of neutrons in boron)=7
7 is the atomic number of Nitrogen (N)
No. of atoms=mols*avagadros no.
N=n*No
N=17 * 6.022 *10^23
No. Of atoms=(17) (6.022*10^23)
Answer:
Helium because it's apart of the noble gases family
