Answer:
1.99 x 10⁻¹⁸J
Explanation:
Given parameters:
Frequency of the wave = 3 x 10¹⁵Hz
Unknown:
Energy of the photon = ?
Solution:
To solve this problem, we use the expression below;
E = hf
Where E is the energy, h is the Planck's constant and f is the frequency
Now insert the parameters and solve for E;
E = 6.63 x 10⁻³⁴ x 3 x 10¹⁵ = 19.9 x 10⁻¹⁹J or 1.99 x 10⁻¹⁸J
Answer:
Similarities: both state the mass of chemical species and they have the same numerical value
Differences: molecular mass refers to one single molecule and molar mass refers to one mole of a molecule
Explanation:
The molecular mass is the value of the mass of each molecule and it is measured in mass units (u). It is calculated adding the mass of each atom of the molecule.
The molar mass is the value of the mass of one mole of molecules, which means the mass of 6.022140857 × 10²³ molecules. The unit is g/mol.
For example, we can consider the methane molecule, which has the chemical formula of CH₄:
Molecular mass CH₄ = C mass + 4 x (H mass)
Molecular mass CH₄ = 12.01 + 4 x (1.01)
Molecular mass CH₄ = 16.05 u
Now to calculate the molar mass we multiply the value of the molecular mass by the Avogadro number and convert the units to g/mol:
Molar mass CH₄: 16.05 x
x 6.022140857 × 10²³ mol⁻¹
Molecular mass CH₄ = 16.05 g / mol
i think its MIDDLE FINGERS UP IN THE SKY AND AT THESE AHOLE MODERATORS
Answer:
Molar mass→ 0.930 g / 6.45×10⁻³ mol = 144.15 g/mol
Explanation:
Let's apply the formula for freezing point depression:
ΔT = Kf . m
ΔT = 74.2°C - 73.4°C → 0.8°C
Difference between the freezing T° of pure solvent and freezing T° of solution
Kf = Cryoscopic constant → 5.5°C/m
So, if we replace in the formula
ΔT = Kf . m → ΔT / Kf = m
0.8°C / 5.5 m/°C = m → 0.0516 mol/kg
These are the moles in 1 kg of solvent so let's find out the moles in our mass of solvent which is 0.125 kg
0.0516 mol/kg . 0.125 kg = 6.45×10⁻³ moles. Now we can determine the molar mass:
Molar mass (mol/kg) → 0.930 g / 6.45×10⁻³ mol = 144.15 g/mol