Hydrogen contains 7.7% by mass of hydrogen and 92.3% by mass of carbon. The relative molecular mass of carbon is 78. Derive the emperical formula and the molecular formula
To derive the empirical formula, we need to determine the ratio of atoms in the compound.
First, we assume we have 100g of the compound. This means we have 7.7g of hydrogen and 92.3g of carbon.
Next, we need to convert the mass of each element into moles. To do this, we divide the mass of each element by their respective molar masses.
The molar mass of hydrogen (H) is 1g/mol, so:
moles of H = 7.7g / 1g/mol = 7.7 mol
The molar mass of carbon (C) is 12g/mol, so:
moles of C = 92.3g / 12g/mol = 7.69 mol
Now, we need to find the simplest whole number ratio between the moles of hydrogen and carbon.
The ratio of moles of H : moles of C is approximately 7.7 : 7.69.
To find the simplest whole number ratio, we divide both numbers by the smallest number (in this case, 7.69):
7.7 mol / 7.69 mol ≈ 1 mol H : 1 mol C
Therefore, the empirical formula is C1H1, which is equivalent to CH.
To determine the molecular formula, we need to know the molecular mass of the compound. However, this information is not provided in the question. Without the molecular mass, we cannot determine the molecular formula.
Calculate the molar mass of A if 1.83gdm-3 of A is used
To calculate the molar mass of A, we need more information. Specifically, we need to know the volume of A that corresponds to the mass of 1.83 g/dm³.
The molar mass is calculated by dividing the mass of a substance by the number of moles of that substance.
Molar mass (g/mol) = Mass (g) / Moles (mol)
Since we are given the concentration (1.83 g/dm³) and not the volume, we cannot determine the moles of A and, therefore, cannot calculate the molar mass.
To find the molar mass, we would need to know either the volume of A used or any other information that allows us to determine the moles of A.
Calculate the mole ratio of acid to base in the reaction expressing your answer as a whole number ratio of one
To calculate the mole ratio of acid to base in a reaction, we need to know the balanced chemical equation for the reaction. Without this information, we cannot determine the mole ratio.
Please provide the balanced chemical equation for the reaction and specify which compound is the acid and which is the base.
For the CH problem it the molar mass of the compound is listed as 78.
Since CH is 12 + 1 = 13, then 78/13 = 6.0; therefore, the molecular formula is C6H6.
Apologies for the confusion in my initial response. You are correct in your calculation.
The molar mass of CH is 13 g/mol (12 g/mol for carbon and 1 g/mol for hydrogen). The given molar mass of 78 g/mol corresponds to a molecular formula that is a multiple of the empirical formula.
To determine the molecular formula, we divide the molar mass of the compound by the molar mass of the empirical formula:
78 g/mol / 13 g/mol = 6
This indicates that the empirical formula (CH) is multiplied by a factor of 6 to obtain the molecular formula.
Therefore, the molecular formula is C6H6.