The molecular mass of pyrene is 204.4 g/mol.
From;
ΔT = Kb m i
Where;
- ΔT = boiling point elevation
- Kb = boiling point constant
- m = molality
- i = Van't Hoff factor
Since the compound is molecular; i = 1
The number of moles of pyrene = 4.04 g/MM
Where; MM = molar mass of pyrene
molality = number of moles of pyrene/mass of solvent in Kg
The mass of solvent = 10 g or 0.01 Kg
molality = 4.04 g/MM/0.01
ΔT = Boiling point of solution - Boiling point of pure solvent
ΔT = 85.1°C - 80.1°C
ΔT = 5°C
5 = 2.53 × 4.04 g/MM/0.01 × 1
5 = 10.22 × 1/0.01 MM
0.05MM = 10.22
MM= 10.22/0.05
MM= 204.4 g/mol
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I don’t get it what do you mean ok
Answer:
Explanation:
Given parameters:
Concentration of H₃O⁺ = 5.6 x 10⁻²M
Solution:
To solve for the concentration of H₃O⁺ in the solution, we simply use the expression below:
pH = -log₁₀[H₃O⁺]
where [H₃O⁺] = 5.6 x 10⁻²M is the concentration of H₃O⁺
pH = -log₁₀[5.6 x 10⁻²] = - x -1.25 = 1.25
Answer:
D
Explanation:
My logic: Electricity produces heat, chemical reactions produce heat. And so on.
Answer:
Doing an Endothermic reaction, energy is absorbed from surroundings
Explanation:
Endothermic reactions:
The type of reactions in which energy is absorbed are called endothermic reactions.
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
we can see that 131 kj/mol energy is taken by the reactants. So energy is absorbed from surrounding.
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
