Answer:
answer A
Explanation:
A) the quantity of usable energy declines with each transformation → True . Since the entropy increases , the amount of energy that can not be converted to useful energy increases and since the total amount of energy is conserved, the quantity of useful energy decreases.
B) energy can be neither created nor destroyed → False in the context of entropy , since the energy is conserved regardless of the changes in entropy (First law → conservation of energy vs second law → increase of entropy)
C) life should be impossible → False . Since the second law states that the entropy of the <u>universe </u>increases with time . Then the system (life) can experience a decrease in entropy at the expense of a larger increase in entropy of the surroundings ( so the net increase is positive)
D) it is not possible to observe an increase in molecular organisation → False . Same as C. A system can experience a decrease in entropy at the expense of a larger increase in entropy of the surroundings ( so the net increase is positive)
scandium. if you look up the number of electrons thats the periodic number and it gives you the answer
Answer:
1.4 mols
4th answer
Explanation:
22. 5 g of O2 in moles = (22.5/32) mols = 0.703 mol
The stoichiometry between O2 and H2O =1: 2
Therefore H2O produced = 2 * 0.703 mols=1.406 mols
Q: A
according to this formula, we can get the mole fraction of water (n):
P(solu) = n Pv(water)
when we have Pv(solu) = 22.8 and Pv(water) = 23.8 so by substitution:
22.8 = n * 23.8
n= 0.958
- we need to get the moles of glucose:
moles of water = 500 g(mass weight) / 18 (molar weight)= 27.7 mol
n = moles of water / ( moles of water + moles of glucose)
0.958 = 27.7 / ( 27.7+ moles of glucose)
0.958 moles of glucose + 26.5 = 27.7
0.968 moles of glucose = 1.2
moles of glucose = 1.253 mol
∴ the mass of glucose = no.of glucose moles x molar mass
= 1.253 x 180 = 225.5 g
Q: B
here we also need to get n (mole fraction of water )by using this formula:
Pv(solu) = n Pv(water)
when we have Pv(solu)=132 & Pv(water)=150 so, by substition:
132= n * 150
n = 0.88
so, mole fraction of solution = 1 - 0.88 = 0.12
and we can get after that the moles of water = (mass weight / molar mass)
- no.moles of water = 85 g / 18 g/mol = 4.7 moles
- total moles in solution = moles of water / moles fraction of water
= 4.7 / 0.88 = 5.34 moles
∴ moles of the solution = total moles in solu - moles of water
= 5.34 - 4.7 = 0.64 moles solute
∴ the molar mass of the solute = mass weight of solute / no.of moles of solute
= 53.8 / 0.64 = 84 g/mole
Q: C
moles of urea (NH2)2 CO = mass weight / molar mass
= 4.49 g / 60 g /mol
= 0.07 mol
moles of methanol = mass weight / molar mass
= 39.9 g / 32 g/mol = 1.25 mol
moles fraction of methanol = moles of methanol / (moles of methanol + moles of urea )
moles fraction of methanol = 1.25 / ( 1.25+0.07) = 0.95
by substitution in Pv formula we will be able to get the vapour pressure of the solu :
Pv(solu) = n P°v
Pv(solu) = 0.95 * 89 mm Hg
∴Pv(solu) = 84.55 mmHg
Umm...Well...
Heisenberg's Uncertainty Principle says that we can never know both the position and rate of change of a particle at any time. We can only know one or the other. This leads to rather silly jokes that deal with uncertainty, probability, and superposition. So, saying that "Heisenberg may have slept here" is essentially saying that it is uncertain if Heisenberg slept there or not, making for a rather silly, but slightly unfunny physics joke.
