Determine the mass in grams of 1.15 × 10²³ atoms of cobalt. A) 0.191 grams B) 5.23 grams C) 11.2 grams D) 12.4 grams E) 308 grams

Question

Quizplus · Accepted Answer

1.15 × 10^23 atoms of cobalt can be converted to moles by dividing with Avogadro's number (6.022 × 10^23). 
1.15 × 10^23 / 6.022 × 10^23 = 0.191 moles 
The molar mass of cobalt is 58.93 g/mol, so the mass of 0.191 moles is: 
0.191 moles x 58.93 g/mol = 11.2 grams 
Therefore, the answer is choice C, 11.2 grams.

Determine the Mass in Grams of 1