Question

Calculate the percent composition by weight of ether \(\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_{2} \mathrm{O}\)

Short answer

The percent composition by weight of Ether \(\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_2 \mathrm{O}\) is: - Carbon (C): 64.76% - Hydrogen (H): 13.59% - Oxygen (O): 21.56%

Step-by-step solution

Determining the molecular weight of ether

Firstly, we need to find the molecular weight of ether. Ether has a chemical formula of \(\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_2 \mathrm{O}\). To find the molecular weight, we need to multiply the atomic weight of each element with the number of atoms present in the molecule and then add all these weights together. The atomic weights are: - Carbon (C): 12.01 g/mol - Hydrogen (H): 1.008 g/mol - Oxygen (O): 16.00 g/mol The chemical formula of ether tells us that there are four Carbon atoms, ten Hydrogen atoms, and one Oxygen atom present in the molecule. Then the molecular weight of ether is: Molecular Weight = (4 × Atomic Weight of C) + (10 × Atomic Weight of H) + (1 × Atomic Weight of O)

Calculate the molecular weight of ether

Using the values of the atomic weights and the formula above, we can calculate the molecular weight of ether: Molecular Weight = (4 × 12.01) + (10 × 1.008) + (16.00) = 48.04 + 10.08 + 16.00 = 74.12 g/mol

Calculate the weight percent of each element

Now we can determine the percent composition of each element in the ether molecule using the molecular weight and the atomic weights of each element: Percent Composition of Carbon (C) = (Total weight of C in ether molecule) / (Molecular weight of ether) × 100 Percent Composition of Hydrogen (H) = (Total weight of H in ether molecule) / (Molecular weight of ether) × 100 Percent Composition of Oxygen (O) = (Total weight of O in ether molecule) / (Molecular weight of ether) × 100 Now, we can determine the percent composition of each element in ether: Percent Composition of C = (48.04 g) / (74.12 g/mol) × 100 = 64.76% Percent Composition of H = (10.08 g) / (74.12 g/mol) × 100 = 13.59% Percent Composition of O = (16.00 g) / (74.12 g/mol) × 100 = 21.56% The percent composition by weight of Ether \(\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_2 \mathrm{O}\) is: - Carbon (C): 64.76% - Hydrogen (H): 13.59% - Oxygen (O): 21.56%

Key concepts

Molecular Weight

Molecular weight is a key concept when dealing with chemical compositions and reactions. It represents the sum of the atomic weights of all atoms in a molecule's chemical formula. For instance, the molecular weight of ether, \[(\text{C}_2 \text{H}_5)_2 \text{O}\]can be calculated by adding up the atomic weights of the elements: Carbon, Hydrogen, and Oxygen. To break down the calculation:

• Carbon (C): There are four Carbon atoms each with an atomic weight of 12.01 g/mol, contributing a total of \(4 \times 12.01 = 48.04\) g/mol.
• Hydrogen (H): With ten Hydrogen atoms each weighing 1.008 g/mol, the sum is \(10 \times 1.008 = 10.08\) g/mol.
• Oxygen (O): There is one Oxygen atom weighing 16.00 g/mol.

Adding these values gives the molecular weight of ether as 74.12 g/mol. Understanding molecular weight helps in determining how substances will react and combine in chemical equations.

Ether

Ether is an organic compound with the chemical formula \[(\text{C}_2 \text{H}_5)_2 \text{O}\], which denotes its structure and components. Ethers are characterized by an oxygen atom connecting two alkyl or aryl groups. They are often used as solvents due to their relatively inert chemical properties. Ethers have a distinct sweet odor and are commonly found in medicine and industry as anesthetics and cleaning agents respectively.The ether in this exercise contains two ethyl groups \((\text{C}_2\text{H}_5 \text{-})\), joined by an oxygen atom. This symmetric structure leads to its usage in various chemical processes, because its bonds are non-polar, rendering it stable under standard chemical conditions. Understanding the role and structure of ether helps one appreciate its functions and uses in the scientific and industrial contexts.

Atomic Weight

Atomic weight, also referred to as atomic mass, is the weighted average of nucleons (protons and neutrons) in the nucleus of an atom of an element. It is crucial for calculating molecular weight and varies slightly from the whole number of nucleons because it accounts for isotopic distribution in nature.For example, in ether \[(\text{C}_2 \text{H}_5)_2 \text{O}\],atomic weights are taken for each element:

• Carbon (C): has an atomic weight of approximately 12.01 g/mol.
• Hydrogen (H): weighs about 1.008 g/mol.
• Oxygen (O): the atomic weight is 16.00 g/mol.

These atomic weights allow chemists to calculate the molecular weight of compounds.Atomic weights are fundamental constants for predictive modeling in chemistry and help guide the synthesis and analysis of chemical structures.

Chemical Formula

The chemical formula is a symbolic representation of the proportions of atoms that constitute a particular chemical compound. For ether, it is represented as \[(\text{C}_2 \text{H}_5)_2 \text{O}\].This notation provides essential information about the types and numbers of atoms involved:

• \(\text{C}_2 \text{H}_5\) is the ethyl group, indicating there are two carbons and five hydrogens bonded together. Two of these groups are present in ether.
• The \(\text{O}\) signifies a single oxygen atom connecting the two ethyl groups.

By understanding chemical formulas, one can comprehend the molecular composition and potential chemical interactions of the compound. It's the basic language of chemistry, allowing scientists to convey a vast amount of information succinctly. Interpreting and using chemical formulas effectively is essential for executing lab work, predicting reaction outcomes, and conducting quantitative analyses in various scientific fields.