Question

how many moles of na₂co₃ are in 52.0 g of na₂co₃?
0.491 mol
0.681 mol
0.253 mol
0.542 mol
0.765 mol

Explanation:

Step1: Calculate the molar mass of \(Na_2CO_3\)

The molar mass of \(Na\) is \(22.99\ g/mol\), \(C\) is \(12.01\ g/mol\), and \(O\) is \(16.00\ g/mol\).
For \(Na_2CO_3\), \(M = 2\times22.99+12.01 + 3\times16.00\)
\(M=45.98 + 12.01+48.00\)
\(M = 105.99\ g/mol\)

Step2: Use the formula \(n=\frac{m}{M}\)

Given \(m = 52.0\ g\) and \(M=105.99\ g/mol\)
\(n=\frac{52.0}{105.99}\approx0.491\ mol\)

Answer:

0.491 mol