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Ch.3 - Molecules and Compounds
Tro - Chemistry: A Molecular Approach 6th Edition
Tro6th EditionChemistry: A Molecular ApproachISBN: 9780137832217Not the one you use?Change textbook
All textbooksTro 6th EditionCh.3 - Molecules and CompoundsProblem 81
Chapter 3, Problem 81

Most fertilizers consist of nitrogen-containing compounds such as NH3, CO(NH2)2, NH4NO3, and (NH4)2SO4. Plants use the nitrogen content in these compounds for protein synthesis. Calculate the mass percent composition of nitrogen in CO(NH2)2.

Verified step by step guidance
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Step 1: Determine the molar mass of the compound CO(NH2)2. The molar mass is calculated by adding up the molar masses of each atom in the compound. The molar mass of carbon (C) is approximately 12.01 g/mol, oxygen (O) is 16.00 g/mol, nitrogen (N) is 14.01 g/mol, and hydrogen (H) is 1.01 g/mol. Since there are two nitrogen atoms and four hydrogen atoms in the compound, remember to multiply their molar masses by 2 and 4 respectively.
Step 2: Calculate the total molar mass of nitrogen in the compound. Since there are two nitrogen atoms in the compound, multiply the molar mass of nitrogen by 2.
Step 3: Calculate the mass percent composition of nitrogen in the compound. The mass percent composition is calculated by dividing the total molar mass of nitrogen by the molar mass of the compound, and then multiplying the result by 100% to get the percentage.
Step 4: The result from step 3 is the mass percent composition of nitrogen in CO(NH2)2.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Molar Mass Calculation

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). To calculate the molar mass of a compound, you sum the atomic masses of all the atoms in its molecular formula. For CO(NH2)2, you would add the molar masses of carbon (C), oxygen (O), and nitrogen (N) based on their respective quantities in the formula.
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Mass Percent Composition

Mass percent composition refers to the percentage by mass of each element in a compound. It is calculated by dividing the mass of the element in one mole of the compound by the total molar mass of the compound, then multiplying by 100. This concept is essential for understanding how much of a compound's mass comes from a specific element, such as nitrogen in CO(NH2)2.

Role of Nitrogen in Plants

Nitrogen is a crucial nutrient for plants, primarily because it is a key component of amino acids, which are the building blocks of proteins. Proteins play vital roles in plant structure and function, including enzyme activity and cellular processes. Understanding the importance of nitrogen helps contextualize why its mass percent in fertilizers like CO(NH2)2 is significant for agricultural practices.
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