Q: What is the change of entropy for 3.0 kg of water when the 3.0 kg of water is changed to ice at 0 °C? (Lf = 3.34 x 105 J/kg)
Answer:
-3670.33 J/K
Explanation:
Entropy: This can be defined as the degree of randomness or disorderliness of a substance. The S.I unit of Entropy is J/K.
Mathematically, change of Entropy can be expressed as,
ΔS = ΔH/T ....................................... Equation 1
Where ΔS = Change of entropy, ΔH = heat change, T = temperature.
ΔH = -(Lf×m).................................... Equation 2
Note: ΔH is negative because heat is lost.
Where Lf = latent heat of ice = 3.34×10⁵ J/kg, m = 3.0 kg, m = mass of water = 3.0 kg
Substitute into equation
ΔH = -(3.34×10⁵×3.0)
ΔH = - 1002000 J.
But T = 0 °C = (0+273) K = 273 K.
Substitute into equation 1
ΔS = -1002000/273
ΔS = -3670.33 J/K
Note: The negative value of ΔS shows that the entropy of water decreases when it is changed to ice at 0 °C
My answer to the question is "Gas particles are acting like tiny,solid spheres".
False. It is a physical change because the molecules of the bread didn't change only the form of the bread changed.
Hello! Your answer is C, one atom of iron and three atoms of chlorine.
In this case, there is some ambiguity with "Cl". It could be C + I, or Cl. (One being carbon + iodine and the other Chlorine). However, we can see that the only choice that mentions iodine states two atoms, which is incorrect, as if it was iodine, the 3 indicates that there would be three atoms.
Therefore, Cl must be chlorine. If you look at choice C, there are three atoms of chlorine, as indicated by the 3 at the end of the Cl. There is also one molecule of Fe, as there is no number at the end of it so there has to be only one.
B is not correct, as carbon would be only "C". A is not correct as a molecule is a collection of atoms bonded together, therefore, this compound could be named a molecule, but there are not multiple molecules inside this compound.
Hope this helps!
