A compound with the empirical formula CH2O has a molar mass of approximately 90 g/mol. What is its molecular formula?
Empirical formula is CH2O. Molecular formuls is (CH2O)x
The empirical formula mass is 12+2+16 = 30 so the molar mass is
30*x = 90
x = 90/30 = 3 therefore, that must be 3 units of CH2O. You can write the molecular formula as (CH2O)3 or as C3H6O3
Thanks! This was extremely helpful since I have a test tomorrow!
Well, if we take a closer look at the empirical formula CH2O, we can see that it contains one carbon atom, two hydrogen atoms, and one oxygen atom.
Now, to find the molecular formula, we need to compare the molar mass of the empirical formula with the molar mass given. The molar mass of the empirical formula (CH2O) is approximately 30 g/mol (12 g/mol for carbon + 2 g/mol for hydrogen + 16 g/mol for oxygen).
Since the molar mass given is 90 g/mol, which is three times greater than the molar mass of the empirical formula, we can conclude that the molecular formula of the compound is three times the empirical formula.
Therefore, the molecular formula of the compound with the empirical formula CH2O is C3H6O3.
And just between us, this compound is often known as "Nice-Try-Higher-Than-Ch2o-lactone". It's a tricky one, but we caught it!
To find the molecular formula of a compound given the empirical formula and the molar mass, we need to compare the molar mass of the empirical formula with the molar mass of the compound.
The empirical formula of the compound is CH2O, which consists of one carbon atom (C), two hydrogen atoms (H), and one oxygen atom (O).
To calculate the molar mass of the empirical formula, we need to consider the atomic masses of carbon (C), hydrogen (H), and oxygen (O) from the periodic table. These values are approximately 12 g/mol for carbon, 1 g/mol for hydrogen, and 16 g/mol for oxygen.
The molar mass of the empirical formula CH2O can be calculated as follows:
(1 × molar mass of carbon) + (2 × molar mass of hydrogen) + (1 × molar mass of oxygen)
= (1 × 12 g/mol) + (2 × 1 g/mol) + (1 × 16 g/mol)
= 12 g/mol + 2 g/mol + 16 g/mol
= 30 g/mol
We know that the molar mass of the compound is approximately 90 g/mol. So, we need to find a whole number multiplier that can be applied to the empirical formula to achieve a molar mass of 90 g/mol.
Dividing the molar mass of the compound (90 g/mol) by the molar mass of the empirical formula (30 g/mol), we get:
90 g/mol ÷ 30 g/mol = 3
This means that the molecular formula of the compound is 3 times the empirical formula:
(CH2O)3 = C3H6O3
Therefore, the molecular formula of the compound is C3H6O3.