Question

What is the molar mass of \( \text{Na}_2\text{CO}_3 \)?

• A. \( 106 \, \text{g/mol} \)
• B. \( 98 \, \text{g/mol} \)
• C. \( 116 \, \text{g/mol} \)
• D. \( 112 \, \text{g/mol} \)

Hint:

To calculate the molar mass, add the atomic masses of all the elements in the compound, considering the number of atoms of each element.

Answer 1

The Correct Option is A

Step 1: Calculate the molar mass of \( \text{Na}_2\text{CO}_3 \) The molecular mass of a compound is the sum of the atomic masses of its elements. - Atomic mass of sodium (Na) = \( 23 \, \text{g/mol} \), - Atomic mass of carbon (C) = \( 12 \, \text{g/mol} \), - Atomic mass of oxygen (O) = \( 16 \, \text{g/mol} \). Step 2: Add the atomic masses The molecular formula of sodium carbonate is \( \text{Na}_2\text{CO}_3 \), which contains: - 2 sodium atoms, - 1 carbon atom, - 3 oxygen atoms. Thus, the molecular mass is: \[ \text{Molecular mass of Na}_2\text{CO}_3 = 2 \times 23 + 1 \times 12 + 3 \times 16 \] \[ = 46 + 12 + 48 = 106 \, \text{g/mol} \] Answer: Therefore, the molar mass of \( \text{Na}_2\text{CO}_3 \) is \( 106 \, \text{g/mol} \). So, the correct answer is option (1).