Answer:
3.6 × 10⁻⁵ M
Explanation:
Ergosterol has a maximum absorbance at λ = 282 nm. The absorbance of an analyte is related to its concentration through the Beer-Lambert's law.
A = ε × <em>l</em> × c
where,
A: absorbance
ε: molar absorptivity
<em>l</em>: optical path length
c; molar concentration
c = A / ε × <em>l </em>= 0.43 / (11,900 M⁻¹cm⁻¹) × 1.00 cm = 3.6 × 10⁻⁵ M
Answer:
The value of 
for this reaction at 1200 K is 4.066.
Explanation:
Partial pressure of water vapor at equilibrium = 
Partial pressure of hydrogen gas at equilibrium = 
Total pressure of the system at equilibrium P = 36.3 Torr
Applying Dalton's law of partial pressure to determine the partial pressure of hydrogen gas at equilibrium:
The expression of is given by:
The value of for this reaction at 1200 K is 4.066.
Answer:
It is a physical change because this change is reversible and no chemical reaction occurs.
Explanation:
Chemical reactions are basically divided into two major classes depending on whether the reaction lose energy or gain energy from the environment during the course of the reaction. The two classes of reaction are exothermic and endothermic reaction.
An exothermic reaction is a type of reaction in which the reaction system lose energy to the environment and thus, the energy content of the reactants is more than that of the product formed. Because of this, the enthapyl change of an exothermic reaction is always negative.
An endothermic reaction is a type of reaction in which the reaction system absorb energy from the environment. Thus, the energy contents of the products is always higher than that of the reactants and the enthapyl change of the reaction is always positive. During the course of the reaction, the reaction container is usually cold to the touch because energy is been absorbed from the environment.
Answer:
Rb: [Kr] 5s
Step-by-step explanation:
Rb is element 37, the first element in Period 5.
It has one valence electron, so its valence electron configuration is 5s.
The noble gas configuration uses the symbol of the previous noble gas as a shortcut for the electron configurations of the inner electrons.
The preceding noble gas is Kr, so the electron configuration is Rb: [Kr] 5s.
