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In the context of chemical reactions, a balanced chemical equation is essential because it represents the conservation of mass. The number of atoms for each element involved in a reaction remains constant throughout the process. For the combustion of ibuprofen, the balanced equation is: \[C_{13}H_{18}O_{2} + 17O_{2} \rightarrow 13CO_{2} + 9H_{2}O\] This equation signifies that one molecule of ibuprofen combines with 17 molecules of oxygen to produce 13 molecules of carbon dioxide and 9 molecules of water. To ensure the equation is balanced, count the atoms of each element on both sides of the equation. All elements鈥攃arbon, hydrogen, and oxygen鈥攎atch up, confirming mass conservation. A balanced equation not only allows for predicting the products of a reaction accurately but is also crucial for further stoichiometric calculations.

The concept of molar mass is pivotal when converting between grams and moles in chemistry. Molar mass is the weight of one mole of a substance and is expressed in grams per mole (g/mol). Calculating molar mass involves adding the atomic masses of all the atoms in the molecule.

For ibuprofen (\(C_{13}H_{18}O_{2}\)):

- Carbon (C): 13 atoms \(\times\) 12.01 g/mol = 156.13 g/mol - Hydrogen (H): 18 atoms \(\times\) 1.01 g/mol = 18.18 g/mol - Oxygen (O): 2 atoms \(\times\) 16.00 g/mol = 32.00 g/mol Summing these gives a molar mass of 206.28 g/mol for ibuprofen.

For \(CO_{2}\):

- Carbon (C): 1 atom \(\times\) 12.01 g/mol = 12.01 g/mol - Oxygen (O): 2 atoms \(\times\) 16.00 g/mol = 32.00 g/mol Total: 44.01 g/mol

For \(H_{2}O\):

- Hydrogen (H): 2 atoms \(\times\) 1.01 g/mol = 2.02 g/mol - Oxygen (O): 1 atom \(\times\) 16.00 g/mol = 16.00 g/mol Total: 18.02 g/molThese molar masses are essential for converting between mass and amount in moles during stoichiometric calculations.

Combustion reactions are a class of chemical reactions where a substance reacts with oxygen gas, often liberating energy in the form of heat and light. These reactions typically involve hydrocarbons and produce carbon dioxide and water as primary products. In the combustion of ibuprofen, the hydrocarbon compound reacts with oxygen to produce: - \(CO_{2}\), representing the carbon atoms in ibuprofen being oxidized. - \(H_{2}O\), representing the hydrogen atoms combining with oxygen.These reactions are exothermic, meaning they release energy. This energy release is one of the reasons combustion reactions are critical in engines and heaters. Understanding the combustion process, especially in organic molecules like ibuprofen, allows chemists to predict the type and amount of products generated, which is crucial in industrial applications and environmental considerations.

Converting moles to grams is a fundamental step in stoichiometry, which helps in quantifying chemical reactions. To perform this conversion, one uses the molar mass of the substance as a conversion factor. This process helps in determining how much of a substance is involved or produced in a reaction.First, compute the number of moles from the given mass using the formula:\[\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}\]Once the moles are known, it's straightforward to convert back to mass:\[\text{grams} = \text{moles} \times \text{molar mass (g/mol)}\]In our exercise, given 0.250 g of ibuprofen, we calculated 0.00121 moles. With the balanced equation, we then found the moles of \(CO_{2}\) and \(H_{2}O\) would be 0.0157 and 0.0109 respectively. Finally, using their molar masses, we converted these moles into grams. This tidy progression from moles to grams enables chemists to predict and measure reaction yields accurately.