Answer:
Electrolytes are substances that can ionize in water. They could be acids, bases or salts as long as they give ions when they dissolve in water.
Explanation:
- <em>Strong electrolytes</em> completely ionize when dissolved in water, leaving no neutral molecules. The strong electrolytes here are:<u> salt water</u>, <u>baking soda (NaHCO3) solution.</u>
- <em>Weak electrolytes</em> do not completely dissociate in solution, and hence have a low ionic yield. Examples of this would be<u> vinegar </u>and <u>bleach </u>(which could be sodium hypochlorite or chlorine, which are weakly dissociated).
- <em>Non-electrolytes </em>will remain as molecules and are not ionized in water at all. In this case, <u>sugar solution is a non-electrolytes</u>, even though sugar dissolves in water, but it remains as a whole molecule and not ions.
Given that,
Work done by the system = 125 J
Energy released when it cools down = 438 J
To find,
The change in internal energy.
Solution,
As heat is released by the system, Q = -438 J
Work done by the system, W = -125 J
Using the first law of thermodynamics. The change in internal energy is given by :
So, the change in internal energy is 563 J.
Answer: <em><u>125 g</u></em>
Explanation:
Mass = Volume × Density
⇒ Mass of the water = 125 mL × 1.0 g/mL
= 125 g
Answer:
X(EtOH) = 0.0891
X(H₂O) = 0.9109
Explanation:
Given 20% aqueous solution ethanol.
Ethanol => C₂H₅OH (or, EtOH) => molecular weight = 46 g//mole
20% solution by weight = 20 grams EtOH / 100 grams of solution
20 grams EtOH / 100 grams of solution = 20 grams EtOH + 80 grams H₂O
moles EtOH = (20g/46g/mol) = 0.4348 mole
moles H₂O = (80g/18g/mol) = 4.4444 mole
moles EtOH + moles H₂O = 0.4348 + 4.4444 = 4.8792
X(EtOH) = 0.4348/4.8792 = 0.0891
X(H₂O) = 4.4444/4.8792 = 0.9109
∑mole fractions must equal 1.000 => 0.0891 + 0.9109 = 1.000 (check!)
