Answer:
- Last choice: <em><u>- 3.72°C</u></em>
Explanation:
The freezing point depression in a solvent is a colligative property: it depends on the number of solute particles.
The equation to predict the freezing point depression in a solvent is:
Where,
- ΔTf is the freezing point depression of the solvent,
- Kf is the cryoscopic molal constant of the solvent, and i is the Van'f Hoff factor, which is the number of ions produced by each unit formula of the ionic compound.
The calcualtions are in the attached pdf file. Please, open it by clicking on the image of the file.
Answer:
Solubility of O₂(g) in 4L water = 3.42 x 10⁻² grams O₂(g)
Explanation:
Graham's Law => Solubility(S) ∝ Applied Pressure(P) => S =k·P
Given P = 0.209Atm & k = 1.28 x 10⁻³mol/L·Atm
=> S = k·P = (1.28 x 10⁻³ mole/L·Atm)0.209Atm = 2.68 x 10⁻³ mol O₂/L water.
∴Solubility of O₂(g) in 4L water at 0.209Atm = (2.68 x 10⁻³mole O₂(g)/L)(4L)(32 g O₂(g)/mol O₂(g)) = <u>3.45 x 10⁻² grams O₂(g) in 4L water. </u>
Explanation:
The given data is as follows.
, 
Area of the flat plate is 2 × 4 = 8 
.
Average convection heat transfer coefficient 
= 
= 
.
Hence, formula to calculate heat transfer through convection from air to the water is given as follows.
q = 
= ![60 W/m^{2} ^{o}C} \times 8 m^{2} \times [(80 - 30)]^{o}C](https://tex.z-dn.net/?f=60%20W%2Fm%5E%7B2%7D%20%5E%7Bo%7DC%7D%20%5Ctimes%208%20m%5E%7B2%7D%20%5Ctimes%20%5B%2880%20-%2030%29%5D%5E%7Bo%7DC)
= 24000 W
or, = 24 kW
Hence, the direction of heat flow is from air to the surface.
Thus, we can conclude that transfer of heat is 24 kW.
All of the factors listed above, except food can be classified as abiotic factors. Food (the presence of plants,animals and other organisms in the ecosystem and their complex relationships) is the biotic component of the ecosystem.
These factors affect the distribution, survival and genetic characteristics of the populations. The lack of water, shelter and space can prevent certain species from living in the ecosystem or cause strong pressure of the natural selection and shape the genetic structure of the population.
Complex biotic relationship also influence behavior, presence and genetic structure of the populations.
