Question

Plants need nitrogen to grow, so many fertilizers consist of nitrogen-containing compounds. Calculate the mass percent composition of nitrogen in each fertilizer: NH3, CO(NH2)2, NH4NO3, (NH4)2SO4. Which fertilizer has the highest nitrogen content?

Short answer

NH3: 82.24%, CO(NH2)2: 46.65%, NH4NO3: 35.00%, (NH4)2SO4: 21.21%. Ammonia (NH3) has the highest nitrogen content.

Step-by-step solution

Calculate Mass of Nitrogen in NH3

Find the molar mass of ammonia (NH3) by adding the atomic masses of nitrogen (14.01 g/mol) and hydrogen (3 * 1.01 g/mol). Calculate the mass percent of nitrogen by dividing the nitrogen mass by the molar mass of NH3 and then multiplying by 100.

Calculate Mass of Nitrogen in CO(NH2)2

Find the molar mass of urea (CO(NH2)2) by adding the atomic masses of carbon (12.01 g/mol), oxygen (16.00 g/mol), nitrogen (2 * 14.01 g/mol), and hydrogen (4 * 1.01 g/mol). Calculate the mass percent of nitrogen by dividing the mass of the two nitrogen atoms by the molar mass of urea, then multiplying by 100.

Calculate Mass of Nitrogen in NH4NO3

Find the molar mass of ammonium nitrate (NH4NO3) by adding the atomic masses of nitrogen (2 * 14.01 g/mol), hydrogen (4 * 1.01 g/mol), and oxygen (3 * 16.00 g/mol). Calculate the mass percent of nitrogen by dividing the mass of the two nitrogen atoms by the molar mass of ammonium nitrate, then multiplying by 100.

Calculate Mass of Nitrogen in (NH4)2SO4

Find the molar mass of ammonium sulfate ((NH4)2SO4) by adding the atomic masses of nitrogen (2 * 14.01 g/mol), hydrogen (8 * 1.01 g/mol), sulfur (32.07 g/mol), and oxygen (4 * 16.00 g/mol). Calculate the mass percent of nitrogen by dividing the mass of the two nitrogen atoms by the molar mass of ammonium sulfate, then multiplying by 100.

Compare Nitrogen Content

Compare the mass percent compositions of nitrogen in each fertilizer to determine which one has the highest nitrogen content.

Key concepts

Nitrogen in Fertilizers

Understanding the role of nitrogen in fertilizers is crucial for improving plant growth. Nitrogen is a key nutrient that helps build proteins in plants, which are essential for creating the structure of plant cells and vital for growth and production. When it comes to fertilizers, the goal is to supply plants with sufficient nitrogen to optimize their health.

Nitrogen can be found in various forms within fertilizers such as ammonia (NH3), urea (CO(NH2)2), ammonium nitrate (NH4NO3), and ammonium sulfate ((NH4)2SO4). Each compound contains nitrogen in different proportions and is used for specific agricultural needs. The effectiveness of a nitrogen-based fertilizer can be determined by calculating the mass percent composition of nitrogen, which indicates the amount of nitrogen available to plants relative to the total mass of the fertilizer.

Farmers and horticulturists choose fertilizers based on a variety of factors, including the mass percent of nitrogen, to make informed decisions about their plant nutrition strategies. A high nitrogen content could potentially increase the yield and health of crops, which is why it's so important to understand and calculate the nitrogen content in fertilizers.

Chemical Composition

The chemical composition of a substance is defined by the types and amounts of atoms that constitute it. In the context of fertilizers, chemical composition is instrumental in determining how each fertilizer will contribute to plant health and soil fertility. For example, ammonia, urea, ammonium nitrate, and ammonium sulfate have different chemical structures and therefore release nitrogen into the soil at different rates and through different mechanisms.

Each molecule of a nitrogen-containing fertilizer consists of nitrogen (N) atoms and other elements like hydrogen (H), carbon (C), oxygen (O), and sulfur (S), in varying ratios. The precise determination of these ratios through stoichiometry calculations enables us to compare the effectiveness of varying fertilizer types when it comes to providing nitrogen to plants.

Moreover, understanding chemical composition is not only important for the application of fertilizers but also for ensuring safety and compliance with environmental regulations. Excess nitrogen can cause runoff and water contamination, so careful consideration of the chemical composition in fertilizers is necessary to balance plant growth with ecological responsibility.

Stoichiometry Calculations

Stoichiometry calculations are mathematical methods used in chemistry to relate the quantities of substances that are involved in chemical reactions. In the case of determining the mass percent composition of nitrogen in fertilizers, stoichiometry helps calculate the proportion of nitrogen by mass in a given compound.

For instance, the calculation involves finding the molar mass of the fertilizer and the total mass of nitrogen atoms within it. By dividing the mass of nitrogen by the total molar mass and multiplying by 100, one can find the mass percent of nitrogen. This process is repeated for different nitrogen-containing fertilizers, allowing for the comparison of their nitrogen contents. Understanding stoichiometry is not only academic but also practical as it aids farmers in choosing the most nitrogen-rich fertilizer for their crops.

It is essential to accurately perform stoichiometry calculations to prevent errors that could lead to the application of the wrong fertilizer amounts. Miscalculations may potentially harm plant growth or the surrounding environment, thus emphasizing the importance of reliable calculations when working with chemical compounds and treatments in agriculture.