Answer : The correct option is, (b) +115 J/mol.K
Explanation :
Formula used :

where,
= change in entropy
= change in enthalpy of vaporization = 40.5 kJ/mol
= boiling point temperature = 352 K
Now put all the given values in the above formula, we get:



Therefore, the standard entropy of vaporization of ethanol at its boiling point is +115 J/mol.K
Answer:
It increases endurance, builds muscle to maintain an optimal body fat composition, promotes cardiovascular health, strengthens the heart, and even improves your overall mood. Combined with weight training, running can help you maintain the perfect balance of mental stimulation and physical fitness.
Explanation:
First, calculate the number of moles of sodium present with the given mass,
31.5 g of sodium x (1 mol sodium/ 23 g sodium) = 1.37 mol sodium
It is given in the equation that for every 2mols of sodium, one mol of H2 is produced.
mols of H2 = (1.37 mols sodium)(1 mol H2/ 2 mols sodium)
mols of H2 = 0.685 mols H2
Then, at STP, 1 mol of gas = 22.4 L.
volume of H2 = (0.685 mols H2)(22.4 L / 1 mol)
volume of H2 = 15.34 L
Answer: 15.34 L
Answer:
Explanation:
Given parameters :
Volume of solution = 100mL
Absorbance of solution = 0.30
Unknown:
Concentration of CuSO₄ in the solution = ?
Solution:
There is relationship between the absorbance and concentration of a solution. They are directly proportional to one another.
A graph of absorbance against concentration gives a value of 0.15M at an absorbance of 0.30.
The concentration is 0.15M
Also, we can use: Beer-Lambert's law;
A = ε mC l
where εm is the molar extinction coefficient
C is the concentration
l is the path length
Since the εm is not given and assuming path length is 1;
Then we solve for the concentration.