Answer:
0.00007975 mole
Explanation:
Number of moles can be calculated as; mass of solute/volume of solvent or concentration of solution x volume of that solution.
In this case:
Concentration of solution = 1.45 M
Mass of solvent (water in this case) = 55.0 mg
55.0 mg of water is equivalent to 0.55 ml of water.
Therefore, volume of solution = 0.055 ml
Hence, number of moles of solute = molarity x volume
1.45 x 0.000055 = 0.00007975 mole