What is the molarity when 20 grams of lioh is added to 200 ml of water?

4.15mol/dm³

Explanation:

Given:

Mass of LiOH = 20g

Volume of water = 200mL

Unkown:

Molarity of the solution =?

Solution:

Molarity is defined as the number of moles of a given solute in a volume of solution.

     Molarity =

We don't know the number of moles of LiOH,

  Number of moles of LiOH =  

Molar mass of LiOH = 7 + 16 + 1 = 24g/mol

 Number of moles of LiOH = = 0.83mole

Note:

    1000mL = 1dm³

     200mL gives 0.2dm³ of the water.

Molarity = = 4.15mol/dm³

c is the answer because when something is left after something evaporates that shows the chemical change.

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