Five vials each contain 12 grams of a solid metal sample. The samples include calcium, platinum, barium, gold, and silver. Which vial has the fewest moles of metal atoms? a. Calcium b. Barium c. Gold d. Silver e. Platinum.

Answer: option c. Gold

Explanation:

Mass of calcium = 12g

Molar Mass of calcium = 40g/mol

n = Mass / Molar Mass = 12/40 = 0.3mol

Mass of platinum = 12g

Molar Mass of platinum = 195g/mol

n = Mass / Molar Mass = 12/195 = 0.062mol

Mass of Barium = 12g

Molar Mass of Barium = 137g/mol

n = Mass / Molar Mass = 12/137 = 0.088mol

Mass of Gold = 12g

Molar Mass of Gold = 197g/mol

n = Mass / Molar Mass = 12/197 = 0.061mol

Mass of silver = 12g

Molar Mass of silver = 108g/mol

n = Mass / Molar Mass = 12/108 = 0.111mol

From the above, gold has the lowest number of mol i. e 0.061mol