How does that mean that the number is a little too late and you don’t have a phone number so you please look at it
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
According to the equation of molarity:
Molarity= no.of moles / volume per liter of Solution
when we have the molarity=0.58 M and the beaker at 150mL so V (per liter) = 150mL/1000 = 0.150 L
by substitution:
∴ No.of moles = Molarity * Volume of solution (per liter)
= 0.58 * 0.150 = 0.087 Moles
Answer:- selenium, Se.
Explanations:- When an element gain electrons then it becomes negatively charged means it forms it's anion. Total electrons of the anion are the sum of electrons and the charge of the anion. In our problem, the element is q and it forms
ion. The Total electrons for the anion
= electrons of q + 2
As per the given info, there are 36 electrons in
ion.
So, 36 = electrons of q + 2
electrons of q = 36 - 2
electrons of q = 34
q, the neutral atom has 34 electrons means it's atomic number is 34. If we check out the periodic table then the element with atomic number 34 is Selenium, Se.