The molecular mass of sodium oxide $(Na_2O)$ is
A) 45.97954.
B) 61.97894.
C) 22.98977.
D) 38.98917.
Answer (2)
Identify the elements and their atomic masses: Sodium (Na) with approximately 22.98977 and Oxygen (O) with approximately 15.9994.
Calculate the total mass contributed by sodium: 2 × 22.98977 = 45.97954 .
Add the mass of oxygen to find the molecular mass of N a 2 O : 45.97954 + 15.9994 = 61.97894 .
The molecular mass of sodium oxide ( N a 2 O ) is 61.97894 .
Explanation
Understanding the Problem We are asked to find the molecular mass of sodium oxide ( N a 2 O ). To do this, we need to sum the atomic masses of each element in the compound, taking into account the number of atoms of each element.
Identifying Atomic Masses First, we identify the elements in the compound: Sodium (Na) and Oxygen (O). We need to find their respective atomic masses from the periodic table. The atomic mass of Sodium (Na) is approximately 22.98977, and the atomic mass of Oxygen (O) is approximately 15.9994.
Calculating Molecular Mass The chemical formula for sodium oxide is N a 2 O , which means there are two sodium atoms and one oxygen atom in each molecule of sodium oxide. Therefore, the molecular mass of N a 2 O is calculated as follows:
Molecular mass of N a 2 O = 2 * (Atomic mass of Na) + (Atomic mass of O)
Substituting the atomic masses, we get:
Molecular mass of N a 2 O = 2 * (22.98977) + 15.9994
Final Calculation Now, we perform the calculation:
2 × 22.98977 = 45.97954
45.97954 + 15.9994 = 61.97894
Therefore, the molecular mass of N a 2 O is 61.97894.
Final Answer The molecular mass of sodium oxide ( N a 2 O ) is 61.97894. Therefore, the correct option is B.
Examples
Understanding molecular mass is crucial in chemistry for calculating the amounts of substances needed in reactions. For example, if you want to synthesize sodium oxide in a lab, knowing its molecular mass allows you to accurately weigh out the required amounts of sodium and oxygen to ensure a complete reaction without wasting materials. This principle extends to various chemical processes, from drug synthesis to material science, making it a fundamental concept in quantitative chemistry.
The molecular mass of sodium oxide (Na₂O) is approximately 61.97894 g/mol, calculated by summing the masses of its constituent elements, sodium and oxygen. Therefore, the correct answer is option B. This involves multiplying the atomic mass of sodium by 2 and adding the atomic mass of oxygen.
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