Answer:

Explanation:
Henry's law states that the solubility of a gas is directly proportional to its partial pressure. The equation may be written as:

Where
is Henry's law constant.
Our strategy will be to identify the Henry's law constant for oxygen given the initial conditions and then use it to find the solubility at different conditions.
Given initially:

Also, at sea level, we have an atmospheric pressure of:

Given mole fraction:

According to Dalton's law of partial pressures, the partial pressure of oxygen is equal to the product of its mole fraction and the total pressure:

Then the equation becomes:

Solve for
:

Now we're given that at an altitude of 12,000 ft, the atmospheric pressure is now:

Apply Henry's law using the constant we found:

Answer: These results show that the body regulates its salt and water balance not only by releasing excess sodium in urine, but by actively retaining or releasing water in urine.
Explanation:
The answer to this question would be: lower molar concentration
Osmotic pressure is influenced by the number of ions and the concentration of the molecule in the solution. In NaCl, the molecule will split into 1 Na+ ion and 1 Cl- ion which results in 2 ions per compound. In MgCl2, the compound will split into 1 Mg2+ ion and 2 Cl- ion which results in 3 ions. Therefore, the osmotic pressure of MgCl2 will be 3/2 times of NaCl.
MgCl2 will need less concentration to achieve same osmotic pressure as NaCl. If the MgCl2 solution is isotonic with NaCl, the concentration of MgCl2 would be lower than NaCl
Answer
7665 years
Procedure
Let N₀ be the amount of carbon-14 present in a living organism. According to the radioactive decay law, the number of carbon-14 atoms, N, left in a dead tissue sample after a certain time, t, is given by the exponential equation:
N = N₀e^(-λt)
where λ is the decay constant which is related to half-life (T1/2) by the equation:

Here, ln(2) is the natural logarithm of 2.
The percent of carbon-14 remaining after time t is given by N/N₀.
Using the first equation, we can determine λt.
The half-life of carbon-14 is 5,720 years, thus, we can calculate λ using the second equation, and then find t.

Solving the second equation for t, and using the λ we have just calculated we will have
t= 7665 years
Answer: Option (b) is the correct answer.
Explanation:
A solution whose constituent particles are uniformly distributed in the solution is known as a homogeneous solution.
In a homogeneous solution, particles of one solute completely dissolves in the solvent. This solution is also known a true solution.
When sand and water are mixed together then after a certain interval of time sand particles will settle at the bottom. Therefore, they do not dissolve in water. So, it is not a homogeneous solution.
When salt and water are mixed together then the salt particles will dissolve in water. Therefore, it is a homogeneous solution.
Salad dressing is not a homogeneous solution as it contains different solutions like oil, lemon juice etc which does not dissolve when mixed together.
On the other hand, soil is also not a homogeneous solution because we can visualize the distinct layers present in a soil. These layers when mixed in a solution does not dissolve so they did not form a homogeneous solution.
Thus, we can conclude that out of the given options, salt and water is a homogeneous mixture.