How many sodium atoms are present in one mole of sodium chromate, [tex]$Na_2CrO_4$[/tex]?

A. [tex]$4.2 \times 10^{24}$[/tex] atoms
B. [tex]$1.2 \times 10^{24}$[/tex] atoms
C. [tex]$2.4 \times 10^{24}$[/tex] atoms
D. [tex]$6.0 \times 10^{23}$[/tex] atoms



Answer :

Certainly! Let's go through the process of figuring out the number of sodium ([tex]\( Na \)[/tex]) atoms in one mole of sodium chromate ([tex]\( Na_2CrO_4 \)[/tex]) step by step.

### Step 1: Understanding the Composition of Sodium Chromate
Sodium chromate has the chemical formula [tex]\( Na_2CrO_4 \)[/tex]. From this formula, we can see that each molecule of sodium chromate contains:
- 2 sodium (Na) atoms,
- 1 chromium (Cr) atom,
- 4 oxygen (O) atoms.

### Step 2: Definition of a Mole
A mole is a basic unit in chemistry that represents [tex]\( 6.022 \times 10^{23} \)[/tex] entities (atoms, molecules, etc.). This number is known as Avogadro's number.

### Step 3: Calculating Sodium Atoms in One Mole of Sodium Chromate
Since one mole of any substance contains [tex]\( 6.022 \times 10^{23} \)[/tex] molecules, one mole of sodium chromate will have [tex]\( 6.022 \times 10^{23} \)[/tex] molecules of [tex]\( Na_2CrO_4 \)[/tex].

Given that each molecule of [tex]\( Na_2CrO_4 \)[/tex] contains 2 sodium atoms, we can find the total number of sodium atoms in one mole of sodium chromate by multiplying the number of molecules by the number of sodium atoms per molecule.

### Step 4: Performing the Calculation
[tex]\[ \text{Number of sodium atoms in one mole of } Na_2CrO_4 = 2 \times 6.022 \times 10^{23} \][/tex]

### Step 5: Simplifying the Result
By doing the multiplication:
[tex]\[ 2 \times 6.022 \times 10^{23} = 1.2044 \times 10^{24} \][/tex]

The result is approximately:
[tex]\[ 1.2 \times 10^{24} \text{ sodium atoms} \][/tex]

### Conclusion
After evaluating the calculations, we find that the number of sodium atoms present in one mole of sodium chromate [tex]\( Na_2CrO_4 \)[/tex] is:

### Answer:
[tex]\[ \boxed{1.2 \times 10^{24}} \text{ atoms} \][/tex]

Therefore, the correct choice is:
B. [tex]\( 1.2 \times 10^{24} \)[/tex] atoms.