Answer:
The volume of the solution is 0.305 liters.
Explanation:
Molar mass is the amount of mass that a substance contains in one mole. The molar mass of K₂Cr₂O₇ is 294 g / mole. Then you can apply the following rule of three: if by definition of molar mass 294 grams of the compound are contained in 1 mole, 180 grams are contained in how many moles?

moles= 0.61
Molarity is a measure of the concentration of a substance that is defined as the number of moles contained in a certain volume. So, the molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:

Molarity is expressed in units
.
In this case:
- molarity= 2 M
- number of moles of solute= 0.61 moles
- volume= ?
Replacing in the definition of molarity:

Solving:

volume= 0.305 liters
<u><em>The volume of the solution is 0.305 liters.</em></u>
Answer:
what is this for? A-level..?!
Explanation:
A mixture is a portion of matter made up of two or more substances called constituents. Mixtures are the product of the mechanical joining of substances without change in chemical nature, and therefore, each constituent retains its properties.
the option 4
This is an incomplete question, here is a complete question.
The Henry's law constant for oxygen dissolved in water is 4.34 × 10⁹ g/L.Pa at 25⁰C.If the partial pressure of oxygen in air is 0.2 atm, under atmospheric conditions, calculate the molar concentration of oxygen in air-saturated and oxygen saturated water.
Answer : The molar concentration of oxygen is, 
Explanation :
As we know that,

where,
= molar solubility of
= ?
= partial pressure of
= 0.2 atm = 1.97×10⁻⁶ Pa
= Henry's law constant = 4.34 × 10⁹ g/L.Pa
Now put all the given values in the above formula, we get:


Now we have to molar concentration of oxygen.
Molar concentration of oxygen = 
Therefore, the molar concentration of oxygen is, 
Answer:
W=-37.6kJ, therefore, work is done on the system.
Explanation:
Hello,
In this case, the first step is to compute the moles of each gas present in the given mixture, by using the total mixture weight the mass compositions and their molar masses:

Next, the total moles:

After that, since the process is isobaric, we can compute the work as:

Therefore, we need to compute both the initial and final volumes which are at 260 °C and 95 °C respectively for the same moles and pressure (isobaric closed system)

Thereby, the magnitude and direction of work turn out:

Thus, we conclude that since it is negative, work is done on the system (first law of thermodynamics).
Regards.