Question

. If 2.1 moles of CaCl2 are dissolved in enough water to make a 0.92-liter solution, what is the resulting molarity?. Answer . . . . . . . . A) 2.3 M CaCl2. B) 0.44 M CaCl2. C) 0.70 M CaCl2. D) 3.0 M CaCl2 .

Answer 1

Number of moles = 2.1 moles of CaCl2

Volume in liters = 0.92 L

Molarity = ?

M = n / V

M = 2.1 / 0.92

= 2.3 M

Answer A

hope this helps!

Answer 2

The definition is M = moles/L. Punch into the calculator and go. Remember to round to two significant figures.
molarity ,=no of mole of solute/volume in liter 
2.1/0.92=2.28mole/l
molarity = 2.3 mole/L