Assume your unknown ketone is 2-pentanone. What is the molar mass of your 2,4-dinitrophenylhydrazone product?
I don't need or even want the answer, I just need an explanation of how to start working the problem. Thanks!
On a sheet of paper you write the formula for pentanone and 2,4Dnph, react them to form the "compound", then count the C, H, O, etc for the formula. Calculate the molar mass by looking up the atomic masses and summing them OR look on the web for a calculator to do that for you.
To determine the molar mass of a compound, we need to consider the molar masses of each element present in the compound and then calculate their sum.
In this case, we are given that the unknown ketone is 2-pentanone. To find the molar mass of 2-pentanone, we need to know the molar masses of each element present in the compound.
The molecular formula of 2-pentanone is C5H10O. To calculate the molar mass, we can use the periodic table to find the atomic masses of carbon (C), hydrogen (H), and oxygen (O).
The atomic mass of carbon (C) is approximately 12.01 g/mol, the atomic mass of hydrogen (H) is approximately 1.01 g/mol, and the atomic mass of oxygen (O) is approximately 16.00 g/mol.
Now, we can multiply the molar masses of each element by the number of atoms of that element in the molecular formula and then add them up:
Molar mass of carbon (C): 12.01 g/mol * 5 = 60.05 g/mol
Molar mass of hydrogen (H): 1.01 g/mol * 10 = 10.10 g/mol
Molar mass of oxygen (O): 16.00 g/mol * 1 = 16.00 g/mol
Finally, we add up the molar masses of each element:
Molar mass of 2-pentanone = Molar mass of carbon + Molar mass of hydrogen + Molar mass of oxygen
= 60.05 g/mol + 10.10 g/mol + 16.00 g/mol
So, to start working the problem, you need to find the atomic masses of carbon (C), hydrogen (H), and oxygen (O) from the periodic table and then multiply them by the number of atoms of each element in the molecular formula (in this case, C5H10O). Finally, add up the molar masses of each element to get the molar mass of 2-pentanone.