Answer:
m = 3 moles/kg
Explanation:
This is a problem of freezing point depression, and the formula or expression to use is the following:
ΔT = i*Kf¨*m (1)
Where:
ΔT: Change of temperature of the solution
i: Van't Hoff factor
m: molality of solution
Kf: molal freezing point depression of water (Kf = 1.86 °C kg/mol)
Now, the value of i is the number of moles of particles obtained when 1 mol of a solute dissolves. In this case, we do not know what kind of solution is, so, we can assume this is a non electrolyte solute, and the value of i = 1.
Let's calculate the value m, which is the molality solving for (1):
m = ΔT/Kf (2)
Finally, let's calculate ΔT:
ΔT = T2 - T1
ΔT = 0 - (-5.58)
ΔT = 5.58 °C
Now, let's replace in (2):
m = 5.58/1.86
<em>m = 3 moles/kg</em>
<em>This is the molality of solution.</em>
<em>The other data of mass, can be used to calculate the molecular mass of this unknown solid, but it's not asked in the question.</em>
Answer:
a) The formal charge on N is 0 in both species.
Explanation:
The formal charge is calculated using the formular;
FC = V-N-B/2
Where;
V = Number of Valence electrons
N = number of nonbonding valence electrons
B = total number of electrons shared in bonds
In NO2-;
The formal charge of N is given as;
FC = 5 - 2 - 6/2
FC = 0
In HNO2
The formal charge of N is given as;
FC = 0
The correct option is;
a) The formal charge on N is 0 in both species.
The answer is d cuz it’s doesn’t make a lot of the formula
Answer:
Electrical energy
Explanation:
Electrical energy is caused by the moving of electrons.
hope it helps!
Answer:
different sizes of the parachute
Explanation:
this is what is being changed throughout the experiment
