Answer:
57.8kg
Explanation:
Potential energy is given by:
Where U is potential energy, m is mass, g is acceleration due to gravity, and h is height. Using this equation:
<span>The density of the solution =1.05 g/ml.
</span><span>The total mass of the resulting solution is = 398.7 g (CaCl2 + water)
</span>
Find moles of CaCl2 and water.
Molar mass of CaCl2 = 110 (approx.)
Moles of CaCl2 = 23.7 / 110 = 0.22
so, moles of Cl- ion = 2 x 0.22 = 0.44 (because each molecule of CaCl2 will give two Cl- ions)
Moles of water = 375 / 18 = 20.83
Now, Mole fraction of CaCl2 = (moles of CaCl2) / (total moles)
total moles = moles of Cl- ions + moles of Ca2+ ions + moles of water
= 0.44 + 0.22 + 20.83
=21.49
So, mole fraction = 0.44 / (21.49) = 0.02
Guess what !!! density is not used. No need
When an acid is neutralized by a base, that means moles of H+ = moles of OH-
moles of H+ = 0.5 M * 0.025 L HCl = 0.0125 moles H+
moles of OH- should be equal to 0.0125 moles, so
0.0125 moles = (x) * 0.025 L NaOH
x is the concentration of NaOH, which we want to find.
x = 0.5 M
The correct answer is C) 0.5 M.
