You have a 95% EtOH stock solution and want a 70% EtOH solution for sterilization purposes. If you want a final volume of 250 mL, how much 95% EtOH must you add, and how much water must you add

65.8mL of water and 184.2mL of the 95% EtOH stock solution must be added.

Explanation:

To solve this question we need to find hoy many times the 95% EtOH must be diluted to obtain a 70% EtOH solution. That is:

95% / 70% = 1.357 times the solution must be diluted.

If we want to make 250mL of the diluted solution, the amount of 95% that must be added is:

250mL / 1.357 times =

184.2mL of the 95% solution must be added

And of water:

250mL - 184.2mL = 65.8mL of water

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.