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:
H₂²⁺(aq) + O₂²⁻(aq) + SO₃²⁻(aq) → SO²⁻₄(aq) + H₂O(l)
Explanation:
H₂²⁺(aq) + O₂²⁻(aq) + Mg²⁺(aq) + SO₃²⁻(aq) → Mg²⁺(aq) + SO²⁻₄(aq) + H₂O(l)
A careful observation of the equation above, shows that the equation is already balanced.
To obtain the net ionic equation, we simply cancel Mg²⁺ from both side of the equation as shown below:
H₂²⁺(aq) + O₂²⁻(aq) + SO₃²⁻(aq) → SO²⁻₄(aq) + H₂O(l)
Answer:
Low energy waves have <u>a long wavelength.</u>
Explanation:
Energy of wave is directly related to the frequency while it is inversely proportional to the wavelength.
If any wave have high energy it will have high frequency and smaller wavelength.
If the wave have lower energy then it will have lower frequency and higher wavelength.
Mathematical relationship:
E = h. f
E = h. c/λ
E= energy
h = planck's constant
f = frequency
c = speed of light
λ = wavelength
Answer:
1 kilogram weight at sea level would be the equivalent of 2 pounds.
Explanation:
It is more likely 9. pH 4 is acidic and pH 9 is basic, and as the pH of a substance gets closer to 0 or 14, the substance becomes more corrosive or reactive. As 4 is closer to 0 than 9 is to 14, there is a much higher chance the solution has a pH of 9, because pH 4 is less neutral and therefore more corrosive/reactive than pH 9.
