5) After performing a routine laboratory synthesis, a chemist was left with more waste product than desired. She wanted to check the pH of the substance to properly dispose
of the waste, but her pH meter was broken, and the lab had run out of litmus paper.
However, she knew that based on her calculations, the solution likely had a hydrogen
ion, H, concentration of 8.7 x 10-5 M. What is the pH of this solution ? Choose the range
of pH values that contains the correct pH.
A) 1-3.9
B) 4-7.9
C) 8-11.9
D) 12-14

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

56 moles of   lieter in chemistry