Answer:
Freezing point is -2.81°C
Explanation:
34g/342gmol^-1 = 0.0994mol
n = m/mr
Molarity= 0.994/ 0.66 = 1.51M
◇T = -i × m ×Kf
Where ◇T is freezing depression
i= Vant Hoff factor
m = molarity
Kf = freezing content = 1.
860kgmol^-1
◇T =-1 × 1.51 × 1.860 = - 2.81°C
<span>47.88 g/mol is the awsner your welcome</span>
Answer:
4.59 × 10⁻³⁶ kJ/photon
Explanation:
Step 1: Given and required data
- Wavelength of the violet light (λ): 433 nm
- Planck's constant (h): 6.63 × 10⁻³⁴ J.s
- Speed of light (c): 3.00 × 10⁸ m/s
Step 2: Convert "λ" to meters
We will use the conversion factor 1 m = 10⁹ nm.
433 nm × 1 m/10⁹ nm = 4.33 × 10⁷ m
Step 3: Calculate the energy (E) of the photon
We will use the Planck-Einstein's relation.
E = h × c/λ
E = 6.63 × 10⁻³⁴ J.s × (3.00 × 10⁸ m/s)/4.33 × 10⁷ m
E = 4.59 × 10⁻³³ J = 4.59 × 10⁻³⁶ kJ
Enthalpy is a state function
Explanation:
The Hess's law allows us to determine the enthalpy change of a reaction because enthalpy is a state function. It does not depend on the individual path take in going from reactants to products in the reaction.
- Enthalpy changes are the heat changes accompanying physical and chemical changes.
- It is the difference between the heat content of product in the final state and the reactants.
- Enthalpy changes for some reactions are not easily measurable experimentally.
- To calculate such heat changes, we apply the Hess's law of heat summation.
- The law states that "the heat change of a reaction is the same whether it occurs in a step or several steps".
- The Hess's law is simply based on the first law of thermodynamics by which we know that energy is conserved in every system.
learn more:
Hess's law brainly.com/question/11293201
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To make sure no cracks are in the crucible and also to remove any moisture present in the crucible by the process of heating.
