Answer:
1.43 M
Explanation:
We'll begin by calculating the number of mole of the solid. This can be obtained as follow:
Mass of solid = 8.60 g
Molar mass of solid = 21.50 g/mol
Mole of solid =?
Mole = mass / molar mass
Mole of solid = 8.60 / 21.50
Mole of solid = 0.4 mole
Next, we shall convert 280 mL to litre (L). This can be obtained as follow:
1000 mL = 1 L
Therefore,
280 mL = 280 mL × 1 L / 1000 mL
280 mL = 0.28 L
Thus, 280 mL is equivalent to 0.28 L.
Finally, we shall determine the molarity of the solution. This can be obtained as illustrated below:
Mole of solid = 0.4 mole
Volume = 0.28 L
Molarity =?
Molarity = mole / Volume
Molarity = 0.4 / 0.28
Molarity = 1.43 M
Thus, the molarity of the solution is 1.43 M.