Answer:
97 minutes and 12 seconds
Explanation:
Let x be the total time
From the first statement

Total time of Dara's exercise is 14580 seconds
40 %


Time when she had completed 40% was 1 hour 37 minutes and 12 seconds
Givens
=====
Ti = 92.8 oC = 92.8 + 273 = 365.8
T2 = 0.4 oC = 0.4 + 273 = 273.4
Vi = 1.54 mL
Vf = ?????
Formula
======
Vi/Ti = Vf / Tf
1.54 / 365.8 = Vf / 273.4
Calculations
=========
1.54 * 273.4 / 355.8 = Vf
vf = 1.15 mL
Comment
=======
if your teacher is concerned about sig digs, the answer is 1 mL. I'm not sure how to show that it is 1 sig dig. You can ask about this.
One formula unit of sodium chloride contains an ionic bond. The sodium loses an electron to become positively charged, the chlorine atom accepts the electron to become negatively charged, and the two oppositely charged ions attract each other. This electrostatic force of attraction is called an ionic bond.