Concept explainers
(a)
Interpretation:
The empirical formula and molecular formula of a compound with percent composition
Concept Introduction:
Empirical Formula:
The empirical formula of a compound is the simplest whole number ratio of each type of atom in a compound. It can be the same as the compound’s molecular formula but not always. An empirical formula can be calculated from information about the mass of each element in a compound or from the percentage composition.
The steps for determining the empirical formula of a compound as follows:
- Obtain the mass of each element present in grams.
- Determine the number of moles of each atom present.
- Divide the number of moles of each element by the smallest number of moles.
- Convert the numbers to whole numbers. The set of whole numbers are the subscripts in the empirical formula.
Molecular formula:
The molecular formula is the expression of the number of atoms of each element in one molecule of a compound if the molar mass value is known the molecular formula is calculated by the empirical formula.
(a)
Answer to Problem 75AE
The empirical formula of the compound is
The molecular formula of compound is
Explanation of Solution
Given,
The molar mass of the compound is
The percentage of carbon is
The percentage of chlorine is
Assuming that
The
The atomic mass of chlorine is
The grams of each element has to be converted to moles as,
The moles of carbon
The moles of chlorine
The empirical formula can be calculated as,
The number of moles can be converted to moles to whole numbers by dividing by the small number.
The empirical formula of the compound is
The molecular formula of the compound can be calculated as,
Mass of the empirical formula
The molecular formula of compound is
(b)
Interpretation:
The empirical formula and molecular formula of a compound with percent composition
Concept Introduction:
Refer to part (a).
(b)
Answer to Problem 75AE
The empirical formula of the compound is
The molecular formula of compound is
Explanation of Solution
Given,
The molar mass of the compound is
The percentage of carbon is
The percentage of chlorine is
Assuming that
The atomic mass of carbon is
The atomic mass of chlorine is
The grams of each element has to be converted to moles as,
The moles of carbon
The moles of chlorine
The empirical formula can be calculated as,
The number of moles can be converted to moles to whole numbers by dividing by the small number.
The empirical formula of the compound is
The molecular formula of the compound can be calculated as,
Mass of the empirical formula
The molecular formula of compound is
(c)
Interpretation:
The empirical formula and molecular formula of a compound with percent composition
Concept Introduction:
Refer to part (a).
(c)
Answer to Problem 75AE
The empirical formula of the compound is
The molecular formula of compound is
Explanation of Solution
Given,
The molar mass of the compound is
The percentage of carbon is
The percentage of chlorine is
Assuming that
The atomic mass of carbon is
The atomic mass of chlorine is
The grams of each element has to be converted to moles as,
The moles of carbon
The moles of chlorine
The empirical formula can be calculated as,
The number of moles can be converted to moles to whole numbers by dividing by the small number.
The empirical formula of the compound is
The molecular formula of the compound can be calculated as,
Mass of the empirical formula
The molecular formula of compound is
(d)
Interpretation:
The empirical formula and molecular formula of a compound with percent composition
Concept Introduction:
Refer to part (a).
(d)
Answer to Problem 75AE
The empirical formula of the compound is
The molecular formula of compound is
Explanation of Solution
Given,
The molar mass of the compound is
The percentage of carbon is
The percentage of chlorine is
Assuming that
The atomic mass of carbon is
The atomic mass of chlorine is
The grams of each element has to be converted to moles as,
The moles of carbon
The moles of chlorine
The empirical formula can be calculated as,
The number of moles can be converted to moles to whole numbers by dividing by the small number.
Since the value is fractional multiply each value by 3. The empirical formula of the compound is
The molecular formula of the compound can be calculated as,
Mass of the empirical formula
The molecular formula of compound is
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Chapter 7 Solutions
EBK FOUNDATIONS OF COLLEGE CHEMISTRY
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