Answer:
0.366m = Molality of the solution
Explanation:
To solve this question we must know the addition of a solute produce decreasing in freezing point regard to the pure solvent. The equation is:
ΔT = m*Kf*i
<em>Where ΔT is change in freezing point </em>
(As freezing point of water is 0°C, the ΔT is 2.72°C)
<em>Kf is freezing point depression constant = 1.86°C/m for water</em>
<em>i is Van't Hoff factor. The number of ions produced when 1 mole of the salt is dissolved = 4 ions for Fe(ClO₃)₃, Fe³⁺ and 3 ClO₃⁻ ions</em>
<em>m is molality of the solution.</em>
<em />
Replacing:
2.72°C = m*1.86°C/m*4
<h3>0.366m = Molality of the solution</h3>
<em />
E = hc/(lamda)
The lamda symbol is wavelength, which this site does not have. I can represent it with an "x" instead.
Plancks constant, h = 6.626×10^-32 J·s
Speed of light, c = 3.00×10^8 m/s
The energy must be greater than or equal to 1×10^-18 J
1×10^-18 J ≤ (6.626×10^-32 J·s)*(3.0×10^8 m/s) / x
x ≤ (6.626×10^-32 J·s)*(3.0×10^8 m/s) / (1×10^-18 J)
x ≤ 1.99×10^-7 m or 199 nm
The wavelength of light must be greater than or equal to 199 nm
Answer:
MgBr2 < MgCl2 < NaBr < NaCl
Explanation:
In order to determinate ionic character, we have to subtract the electronegativity from the elements involved. This is known as Pauling rule.
MgBr2 > ΔΕΝ = 1.8
NaCl > ΔΕΝ = 2.3
MgCl2 > ΔΕΝ = 2
NaBr > ΔΕΝ = 2.1
1. Subscript is below
2. Coefficient large 2 indicates the number of moles
3. Atoms
1/2 O2 + H2 —> H2O
It’s the atoms that balance on each side
Notes that 1/2 is the coefficient and 2 is the subscript in H2 and H2O
