Please help me in finding this relative molecular weight

[shaiqbashir]

Hi Guys!

my question goes like this

a 5% solution of urea is isotonics with 0.877% of Solute A. Calculate the relative molecular weight of solute A.


now my dear friend, i know its a very simple question but unfortunately, just can't getting any interpretation. I know isotonics sol means having same no. of moles. and i know that Grahams's law of diffusion as well. Please help me so that i can understand this question.

 

[iansmith]

The question has basicly two component. First you have to find the molarity of the urea solution solution. All the information that you require are in the first 5 words of the question.

The second part requires you to estimate the molecular weight of the solute A using the molarity of the urea solution and that the solutions are isotonic. So you know the molarity of the solute solution and you know the amount of solute A in the solution. You have to calculate your way up to the molecular weight.

 

[Blueshift5]

Sure, I can help you find the relative molecular weight of solute A in this scenario. To start, let's define some terms and equations that will be useful in solving this problem.

First, the term "solute" refers to the substance that is being dissolved in a solution. In this case, solute A is being dissolved in a 5% solution of urea.

Next, we need to use the equation for calculating the concentration of a solution, which is:

Concentration = (mass of solute / volume of solution) x 100

In this case, we are given the concentration of the urea solution (5%) and the concentration of solute A (0.877%). We can set up a proportion to find the ratio of solute A to urea in the solution:

0.877/5 = x/100

Solving for x, we get x = 17.54. This means that for every 100 parts of solution, there are 17.54 parts of solute A.

Now, let's use Graham's law of diffusion, which states that the rate of diffusion of a gas is inversely proportional to the square root of its molecular weight. Since we are dealing with a solution, we can use this law by assuming that the rate of diffusion is directly proportional to the concentration of the solute (since more solute particles will lead to a higher rate of diffusion).

We can set up another proportion to find the ratio of the molecular weight of solute A to the molecular weight of urea:

Molecular weight of solute A / Molecular weight of urea = 17.54/5

Solving for the molecular weight of solute A, we get a value of 88.7 g/mol. This is the relative molecular weight of solute A in this scenario.

I hope this explanation helps you understand the problem better. Let me know if you have any further questions.