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Calculate the percent composition of carbon in CO2 given its molar mass.
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Percent of Carbon = (12.01 / 44.01) x 100% = 27.29%
Can a compound have the same empirical and molecular formula? Provide an example.
Yes. An example is carbon dioxide (CO2) where both the empirical and molecular formulas are the same.
Outline the steps to determine the empirical formula from a percent composition.
1. Assume a 100g sample. Convert percentages to grams. 2. Convert grams to moles using molar masses. 3. Divide by the smallest mole value to get whole number ratios. 4. If necessary, multiply by a common factor to get whole number subscripts.
Define molecular formula.
A molecular formula is the actual number of atoms of each element in a compound.
What is the relationship between empirical formulas and molecular formulas?
The molecular formula is a whole number multiple of the empirical formula.
Define empirical formula.
An empirical formula is the simplest whole number ratio of elements in a compound.
Given the percent compositions: 40.92% C, 4.58% H, and 54.50% O, what is the empirical formula?
Convert grams of each to moles, divide by the smallest mole value, and adjust to whole numbers to get C3H4O3.
What is the formula to calculate the percent composition of a compound?
Percent = (Part / Total) x 100%
How is the molar mass of carbon dioxide (CO2) determined?
The molar mass of CO2 is determined by summing the molar masses of carbon and the oxygens. Carbon: 12.01 g/mol, Oxygen: 16 g/mol each. Total Molar Mass of CO2 = 12.01 + 16 + 16 = 44.01 g/mol.
Why are empirical formulas particularly useful?
Empirical formulas are useful for quick calculations and comparisons without the need for expensive equipment.
A compound has an empirical formula of C4H5ON2 and an empirical mass of 97.11 g/mol. Given the molar mass range of 180-200 g/mol, what is the molecular formula?
Given the molar mass range, the empirical mass should be doubled: 2 x 97.11 = 194.22 g/mol. Thus, the molecular formula is C8H10O2N4.
Calculate the percent composition of oxygen in CO2 given its molar mass.
Percent of Oxygen = (32 / 44.01) x 100% = 72.71%
What is the empirical formula of acetylene (C2H2)?
The empirical formula of acetylene is CH.
What is the empirical formula of benzene (C6H6)?
The empirical formula of benzene is CH.
Describe how to determine the molecular formula from the empirical formula and molar mass.
1. Calculate the empirical formula mass. 2. Determine the multiple by comparing the empirical mass to the given molar mass. 3. Multiply the empirical formula by this multiple.
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