please comment to each post.

1.The question asks what the molarity of H3PO4 is, and the given is that 85.5% H3PO4 indicates that 85.5% of the solution, or one gram, is made up of H3PO4. Then we can consider that the initial mass of the solution is we have 100grams of solution and a simple rule of three:

X=85.5*100/100= 85.5g

We currently have 100 grams of total solution, but we need to know how many liters that is equivalent to, and the given the density, we can determine this as:

100(g)/1.69(g/ml) = 59.17 ml

Now pass it to liters:

59.17ml/1000 (ml/L) = 0.05917 L

We now convert the quantity of H3PO4 in grams to moles using the molecular weight:

98 g/mol

85.5 (g) / 98 (g/mol) = 0.8724 moles.

And last, molarity is moles/L -> 0.8724moles/0.05917L=14.744M

The second question asks what is the mole fraction of urea, CO(NH2)2, in a solution prepared by dissolving 5.6 g of urea in 30.1 g of methanol, CH3OH?

This is the structure map we need to do – Urea Mole Fraction = Urea Moles/ Total Moles. With the help of each element’s molecular weight, we must convert those grams into moles.

5.6 (gUrea) / 60.06 (g/moles) = 0.09324 moles

30.1 (gmethanol) / 32.04 (g/moles) = 0.93945 moles

At this point, there will be a total of:

Urea moles+Methanol moles= 0.09324 moles + 0.93945 moles = 1.03269 moles

Next we put it in the Urea Mole Fraction!!!

Mole Fraction= Urea Moles/ Total Moles =

0.09324 moles/1.03269 moles = 0.0903 -> 0.0903 * 100%= 9.03%

Understanding the concept of solute concentration in nursing is critical since it is applied in so many different contexts. It is vital to utilize units of any value to guarantee proper medicine dose or to record levels of chemicals in blood. Knowing solution concentration aids in preparing the appropriate dose for patients and avoiding overdosing or underdosing.

2/The molarity of H3PO4 is 17.24 mol/L. I got this answer by dividing 85.5g (given) by the molar mass of H3PO4 (98.00 g/mol). This answer gave me the number of moles in the solute (0.872 moles). I then used the density and mass given in the equation to calculate the volume. Volume= mass/density; V= 85.5 g/1.69 g/mL ? V= 50.59 mL x 10-3 to give us 0.05059 L. Molarity is the number of moles in a solute divided by the volume of a solution. I calculated the molarity by dividing 0.872 mol by 0.05059 L to get a 17.2 mol/L molarity. 

To calculate the mole fraction of CO(NH2)2, we divide the given mass of urea by the molar mass of urea 5.6 g/60.06 g/mol to give us 0.09324 mol. We do the same for methanol, dividing the given mass of 30.1 g by the molar mass of CH3OH, 32.042 g/mol to get an answer of 0.9393 mol. We then add the two moles together to get 1.03 total moles. Then we divide 0.09324 by the total mole amount to get the mole fraction of urea, 0.090. 

The concept of molarity will be vital in our future careers as nurses as it allows us to determine the concentration of a solution, which is important when giving medications.