Answer:
Given
mass of solute (m) =20.5g
mass of solvent( ms) =155g
solution
malality =mX1000/mrxms
M=20.5x1000/62x155
M=2.1332
Using the equation for boiling point elevation Δt
Δt = i Kb m
we can find the new boiling point T for the solution:
Δt = T - 100∘C
since we know that pure water boils at 100 °C.
We know that the van't Hoff Factor i is equal to 1 because sugar does not dissociate in water.
Also, the value of Ebullioscopic constant Kb for water is listed as 0.512 °C·kg/mol.
The molality m of the solution of 6 moles of sugar dissolved in a kilogram of water can be calculated as
m = 6 moles / 1 kg
= 6 mol/kg
Therefore the new boiling point T would be
T - 100 °C = i Kb m
T = i Kb m + 100 °C.
= (1) (0.512 °C·kg/mol) (6 mol/kg) + 100 °C
= 3.072 °C + 100 °C
= 103.072 °C
Answer:
B. Electrical charges of polar covalent bonds
Explanation:
Lewis structures, also known as Lewis dot diagrams are diagrams that show the bonding between atoms of a molecule and lone pairs of an electron that may exist in the molecule.
Polar covalent bonds are bonds that occur where a pair of electrons is shared unevenly between two atoms
The Lewis notation as an agreed convection, uses the delta sign to indicate polar covalent bonds when they occur in compounds. It shows that the electrons are shared unevenly.
Consider the example attached below. The Lewis structure for HF is given. the δ+ is used to show the electropositive Hydrogen atom while the δ- is used to show the electronegative Fluorine atom in the bond.
Sodium is Na, so there's 3 moles of that. Phosphorus is P, there's 1 mole of that. Oxygen is O, there's 4 moles of that.