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:
SATURATED: Saturated fat is a type of fat in which the fatty acid chains have all or predominantly single bonds.
UNSATURATED: Unsaturated fats are loosely packed. They tend to be liquid at room temperature.
<em>There are two main types of unsaturated fat:</em>
<u>Monounsaturated</u>
<u>Polyunsaturated</u>
Answer:
b. a compound.
Explanation:
Electrolysis is described as a mechanism in which ionic compounds are decomposed into their elements by transmitting a direct electric current via the compound in a liquid state. At the cathode, the cations are reduced and anions at the anode are oxidized. There is an exchange between ions and atoms in the electrolysis process caused by the addition or removal between electrons from the external circuit. As per the question, the original substance is a compound because the electrolysis method is used to obtain pure elements from their respective compound.
To calculate the number of atoms of Cr, we first find the number of moles per unit of cubic centimeter of Cr. Then, use avogadros number for the number of atoms. Calculations are as follows:
1 cm^3 (7.15 g/cm^3) (1 mol / 51.996 g Cr) = 0.14 mol Cr
0.14 mol Cr ( 6.022 x 10^23 atoms Cr / 1 mol Cr ) = 8.28 x 10^22 atoms Cr
Explanation:
The molecular formula for Sodium Nitrate is NaNO3. The SI base unit for amount of substance is the mole. 1 grams Sodium Nitrate is equal to 0.011765443644878 mole.
