Example of Finding Reactant Empirical Formula
TLDRIn this educational video, the process of determining the empirical formula of an acid isolated from clover leaves is meticulously explained. The acid, composed solely of carbon, hydrogen, and oxygen, is heated in oxygen to produce carbon dioxide and water. Through a series of calculations involving molar mass conversions, the instructor deduces the acid's composition and concludes with the empirical formula CHO2, providing a clear demonstration of chemical analysis.
Takeaways
- 🔍 The problem involves determining the empirical formula of an acid isolated from clover leaves, composed of carbon, hydrogen, and oxygen.
- 🔥 The acid is heated in oxygen, resulting in the production of carbon dioxide and water, with their respective masses given as 0.501 grams and 0.103 grams.
- 📝 The process involves writing the chemical reaction in general terms, without balancing, due to the unknown quantities of carbon, hydrogen, and oxygen in the acid.
- 🧪 The moles of carbon in the acid are determined by converting the mass of produced carbon dioxide to moles, using its molar mass (44 g/mol).
- ⚖️ The mass of carbon in the original acid is calculated by multiplying the moles of carbon by the molar mass of carbon (12 g/mol), yielding 0.137 grams.
- 💧 The moles of hydrogen are found by converting the mass of produced water to moles and then doubling it to account for the two hydrogen atoms per water molecule, resulting in 0.0114 moles of hydrogen.
- 🔄 The mass of hydrogen in the original acid is calculated similarly, using the molar mass of hydrogen (1 g/mol), confirming 0.0114 grams of hydrogen.
- 🧐 The mass of oxygen in the acid is deduced by subtracting the masses of carbon and hydrogen from the total mass of the acid, revealing 0.365 grams of oxygen.
- 📉 The moles of oxygen are calculated by dividing the mass of oxygen by its molar mass (16 g/mol), resulting in approximately 0.0228 moles.
- 🔢 The empirical formula is determined by finding the simplest whole number ratio of moles of carbon, hydrogen, and oxygen, which turns out to be 1:1:2.
- 🏁 The empirical formula for the mystery acid is concluded to be CHO2, based on the calculated ratios of the elements.
Q & A
What is the problem presented in the script?
-The problem involves determining the empirical formula of an acid isolated from clover leaves, which contains only carbon, hydrogen, and oxygen. The acid is heated in oxygen, and the amounts of carbon dioxide and water produced are measured.
What are the initial measurements given for the acid and its products?
-The initial measurements are 0.513 grams of the acid, 0.501 grams of carbon dioxide, and 0.103 grams of water produced upon heating.
Why can't the equation for the reaction be balanced initially?
-The equation can't be balanced initially because the number of carbons, hydrogens, and oxygens in the acid is unknown.
What is the first step in determining the empirical formula?
-The first step is to calculate the moles of carbon dioxide produced, which will indicate the moles of carbon in the original acid.
How is the molar mass of carbon dioxide calculated?
-The molar mass of carbon dioxide is calculated as 12 (for carbon) plus 2 times 16 (for oxygen), which equals 44 grams per mole.
What is the molar mass of water and how is it used in the calculation?
-The molar mass of water is 18 grams per mole (2 for hydrogen and 16 for oxygen). It is used to convert the grams of water produced into moles of water.
How are the moles of hydrogen in the original acid determined?
-The moles of hydrogen are determined by multiplying the moles of water by 2, since each molecule of water contains two hydrogen atoms.
What is the molar mass of hydrogen and how is it used in the calculation?
-The molar mass of hydrogen is 1 gram per mole. It is used to convert the moles of hydrogen into grams.
How is the mass of oxygen in the original acid calculated?
-The mass of oxygen is calculated by subtracting the mass of carbon and hydrogen from the total mass of the acid.
What is the empirical formula of the acid determined to be?
-The empirical formula of the acid is determined to be CHO2, based on the simplest whole number ratios of carbon, hydrogen, and oxygen.
Why is the empirical formula important in this context?
-The empirical formula provides the simplest whole number ratios of the elements in the compound, which is crucial for understanding its composition and properties.
Outlines
🔍 Determining the Empirical Formula of an Acid
The script begins by presenting a chemistry problem involving the determination of an empirical formula for an acid isolated from clover leaves. The acid contains carbon, hydrogen, and oxygen. The process involves heating 0.513 grams of the acid in oxygen, resulting in the production of 0.501 grams of carbon dioxide and 0.103 grams of water. The goal is to find the simplest whole number ratio of these elements in the acid. The script emphasizes the importance of understanding the molar ratios of carbon, hydrogen, and oxygen derived from the products to deduce the acid's empirical formula.
🧪 Calculating Moles of Carbon from Carbon Dioxide
This paragraph delves into the calculation of moles of carbon in the original acid by using the mass of carbon dioxide produced. The molar mass of carbon dioxide (44 grams per mole) is used to convert the mass of carbon dioxide into moles, revealing 0.0114 moles of carbon dioxide, which equates to the same number of moles of carbon. The script then converts these moles of carbon into grams, using the molar mass of carbon (12 grams per mole), resulting in 0.137 grams of carbon in the original substance.
💧 Determining Hydrogen Content from Water Production
The script continues with the calculation of hydrogen content in the original acid using the mass of water produced. The molar mass of water (18 grams per mole) is applied to convert the mass of water into moles, yielding 0.00572 moles of water. Since each water molecule contains two hydrogen atoms, this is multiplied by two to find the moles of hydrogen, which amounts to 0.0114 moles. The molar mass of hydrogen (1 gram per mole) is then used to convert moles of hydrogen into grams, resulting in 0.0114 grams of hydrogen in the original substance.
🔄 Finding the Moles of Oxygen and the Empirical Formula
The final paragraph focuses on determining the moles of oxygen in the original acid. By subtracting the mass of carbon and hydrogen from the total mass of the acid, the mass of oxygen is found to be 0.365 grams. Using the molar mass of oxygen (16 grams per mole), this mass is converted into moles, yielding 0.0228 moles of oxygen. The script then simplifies the molar ratios of carbon, hydrogen, and oxygen to their smallest whole numbers, revealing a 1:1:2 ratio. This leads to the empirical formula CHO2 for the acid, concluding the problem-solving process.
Mindmap
Keywords
💡Empirical formula
💡Carbon dioxide (CO2)
💡Water (H2O)
💡Molar mass
💡Moles
💡Elemental analysis
💡Oxygen
💡Significant figures
💡Dimensional analysis
💡Ratio
💡Mystery acid
Highlights
Isolating an acid from clover leaves containing only carbon, hydrogen, and oxygen.
Heating 0.513 grams of the acid in oxygen produces 0.501 grams of carbon dioxide and 0.103 grams of water.
Determining the empirical formula for the unknown acid.
Writing the reaction equation in general terms with x carbons, y hydrogens, and z oxygens.
Using the amounts of carbon dioxide and water to find the moles of carbon and hydrogen in the original acid.
Calculating the molar mass of carbon dioxide to convert grams to moles.
Determining the moles of carbon in the product and the original acid.
Converting the grams of carbon to moles using the molar mass of carbon.
Calculating the moles of water to find the moles of hydrogen in the acid.
Using the molar mass of water to convert grams to moles and then finding moles of hydrogen.
Determining the mass of hydrogen in the original acid.
Calculating the mass of oxygen in the original acid by subtracting carbon and hydrogen masses from the total.
Converting the grams of oxygen to moles using the molar mass of oxygen.
Finding the simplest whole number ratio of moles of carbon, hydrogen, and oxygen.
Determining the empirical formula of the acid to be CHO2.
The process demonstrates a methodical approach to deducing the composition of an unknown substance.
The problem-solving technique has practical applications in chemical analysis and forensic science.
Transcripts
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