To find out how many sodium atoms are present in one mole of sodium chromate (Na _2 CrO _4), we can follow these steps:
1. Determine the number of sodium atoms per formula unit of sodium chromate:
- Sodium chromate (Na _2 CrO _4) has the chemical formula that shows it contains 2 sodium (Na) atoms.
2. Understand Avogadro's number:
- Avogadro's number is [tex]\( 6.022 \times 10^{23} \)[/tex], which represents the number of units (atoms, molecules, etc.) in one mole of any substance.
3. Calculate the total number of sodium atoms in one mole of sodium chromate:
- Since one mole of sodium chromate contains [tex]\( 6.022 \times 10^{23} \)[/tex] formula units and each formula unit contains 2 sodium atoms, you need to multiply the number of formula units by the number of sodium atoms per formula unit.
[tex]\[ \text{Total sodium atoms} = 2 \times 6.022 \times 10^{23} \][/tex]
4. Perform the multiplication:
-
[tex]\[ 2 \times 6.022 \times 10^{23} = 1.204 \times 10^{24} \][/tex]
Therefore, the number of sodium atoms present in one mole of sodium chromate is [tex]\( 1.204 \times 10^{24} \)[/tex] atoms.
This matches with the option [tex]\( 1.2 \times 10^{24} \)[/tex] atoms. Thus, the correct answer is:
[tex]\[ 1.2 \times 10^{24} \text{ atoms} \][/tex]
