Theodore Richards; first scienstist to recieve nobel prize in Chemistry, earning the award "in recognition of his exact determinations of atomic weights of a large number of chemical elements."

6 0

2 years ago

A pharmacist has calculated that a patient requires 30 mmol of phosphate and 80 meq of potassium to be added to the pn. how many

aalyn [17]

Since potassium and phosphate is what we are to find for and they are both found in the potassium phosphate solution, therefore we solve for this one first on the basis of the phosphate.

The formula for finding the volume given the concentration and number of moles is:

Volume = number of moles / concentration in Molarity

Volume potassium phosphate required = 30 mmol phosphate / (3 mmol / mL)

Volume potassium phosphate required = 10 mL

This would also contain potassium in amounts of:

Amount of potassium in potassium phosphate = 10 mL (4.4 meg / mL)

Amount of potassium in potassium phosphate = 44 meg

Therefore the potassium chloride required is:

Volume of potassium chloride = (80 meg – 44 meg) / (2 meg / mL)

Volume of potassium chloride = 72 mL

8 0

2 years ago

Draw the Lewis structure for methane (CH4) and ethane (C2H6) in the box below. Then predict which would have the higher boiling

Alinara [238K]

Answer:

Ethane would have a higher boiling point.

Explanation:

In this case, for the lewis structures, we have to keep in mind that all atoms must have 8 electrons (except hydrogen). Additionally, each carbon would have 4 valence electrons, with this in mind, for methane we have to put the hydrogens around the carbon, and with this structure, we will have 8 electrons for the carbon. In ethane, we will have a bond between the carbons, therefore we have to put three hydrogens around each carbon to obtain 8 electrons for each carbon.

Now, the main difference between methane and ethane is an additional carbon. In ethane, we have an additional carbon, therefore due to this additional carbon, we will have more area of interaction for ethane. If we have more area of interaction we have to give more energy to the molecule to convert from liquid to gas, so, the ethane will have a higher boiling point.

I hope it helps!

7 0

2 years ago