Answer: During winter the Northern Hemisphere leans away from the sun, there are fewer daylight hours and the sun hits us at an angle. This makes it appear lower in the sky. In equatorial regions the length of days and the directness of sunlight don't change as much.
Hope this helps :)
Answer: D. An increase in entropy
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an disordered arrangement to an ordered arrangement, the entropy is said to increase and vice versa.
For a reaction to be spontaneous, the enthalpy of the solution must decrease and the entropy must increase.
To overcome a positive enthalpy of solution and allow a solid solute to dissolve in water, an increase in entropy would make the reaction spontaneous as the system would move to a more disordered state.
Answer:
Density depends on the amount of the substance you have, as the mass will increase, but also what the volume is because if you have a high mass object with an extremely high volume, it won't be very dense. But if you have a high mass object with a low volume, it will be very dense.
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
Answer:
76.5g KCl/74.55 grams per mole Kcl = x
molality= x/.085 kg H2O
Explanation:
well remember molality is moles of solute/kilograms of solvent. So it's the moles of KCl over 85 g of h20 converted into kg. if this makes sense.
