How many moles of each element are in one mole of [tex]$\left( NH _4\right)_2 S$[/tex]?
A. 1 mole of nitrogen, 8 moles of hydrogen, 1 mole of sulfur
B. 1 mole of nitrogen, 6 moles of hydrogen, 1 mole of sulfur
C. 2 moles of nitrogen, 6 moles of hydrogen, 1 mole of sulfur
D. 2 moles of nitrogen, 8 moles of hydrogen, 1 mole of sulfur
Answer (2)
Analyze the chemical formula ( N H 4 ) 2 S to identify the elements present: nitrogen (N), hydrogen (H), and sulfur (S).
Calculate the moles of nitrogen: 1 × 2 = 2 moles.
Calculate the moles of hydrogen: 4 × 2 = 8 moles.
Determine the moles of sulfur: 1 mole. The final answer is 2 moles of nitrogen, 8 moles of hydrogen, 1 mole of sulfur .
Explanation
Understanding the Problem We are asked to find the number of moles of each element in one mole of ( N H 4 ) 2 S . This compound consists of ammonium ions ( N H 4 + ) and sulfide ions ( S 2 − ) . We need to determine how many moles of nitrogen (N), hydrogen (H), and sulfur (S) are present in one mole of ( N H 4 ) 2 S .
Analyzing the Chemical Formula The chemical formula ( N H 4 ) 2 S tells us the composition of the compound. The subscript 2 outside the parenthesis indicates that there are two ammonium ions ( N H 4 + ) for every one sulfide ion ( S 2 − ) .
Calculating the Number of Moles for Each Element Let's break down the calculation for each element:
Nitrogen (N): Each ammonium ion ( N H 4 + ) contains 1 nitrogen atom. Since there are two ammonium ions, there are 1 × 2 = 2 nitrogen atoms.
Hydrogen (H): Each ammonium ion ( N H 4 + ) contains 4 hydrogen atoms. Since there are two ammonium ions, there are 4 × 2 = 8 hydrogen atoms.
Sulfur (S): There is one sulfide ion ( S 2 − ) per formula unit, which contains 1 sulfur atom.
Final Answer Therefore, one mole of ( N H 4 ) 2 S contains 2 moles of nitrogen, 8 moles of hydrogen, and 1 mole of sulfur.
Examples
Understanding the composition of chemical compounds is crucial in various fields. For instance, in agriculture, fertilizers are often composed of compounds like ammonium sulfate ( N H 4 ) 2 S O 4 . Knowing the exact number of moles of nitrogen, hydrogen, sulfur, and oxygen in this compound helps farmers determine the appropriate amount of fertilizer to use for optimal plant growth. Similarly, in pharmaceuticals, understanding the elemental composition of drugs is essential for dosage calculations and ensuring the drug's effectiveness and safety. In materials science, the properties of materials are often directly related to their elemental composition, making this knowledge vital for designing new materials with specific characteristics.
In one mole of ( N H 4 ) 2 S , there are 2 moles of nitrogen, 8 moles of hydrogen, and 1 mole of sulfur. This corresponds to option D. The breakdown of the moles is based on the number of ammonium ions and the sulfur ion present in the formula.
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