Prepare 2 Liters of a 4 molal (be careful with the terminology - I am asking for molality, not molarity) solution of MgSo. (Magnesium Sulfate) in water. Magnesium Sulfate is a medication
used to prevent seizures in a condition termed preeclampsia in pregnancy. The MgSo, is the
solute and water is the solvent. Use rounded numerical atomic weights instead of exact ones with decimal values.
A. How much MgSO, should be weighed out?
B.
How many molecules of MgSO4 are in the solution?
C. How many individual atoms of solute are present?
D. How much water should be added?

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j