Question

what subscript is missing from this compound if the student calculated that there should be 21 atoms in total to produce a molecule of trisodium citrate? na₃c__h₅o₇ 21 6 1 2

Explanation:

Step1: Calculate the number of known atoms

The number of \(Na\) atoms is \(3\), \(H\) atoms is \(5\), \(O\) atoms is \(7\). The sum of known atoms is \(3 + 5+7=15\).

Step2: Find the number of \(C\) atoms

Let the number of \(C\) atoms (the missing sub - script) be \(x\). We know that the total number of atoms is \(21\). So, \(x+15 = 21\). Solving for \(x\), we get \(x=21 - 15\).

Answer:

\(6\)