Calculate the mass of fe(no3)3 that is measured to prepare 500.0 mL of a 0.175mol/L solution.

21.3g

Explanation:

The formula of the compound is;

        Fe(NO₃)₃

Given:

volume  = 500mL  = 0.5L

concentration  = 0.175mol/L

Unknown:

Mass of  Fe(NO₃)₃ measured = ?

Solution:

To solve this problem, find the number of moles first;

      Number of moles of  Fe(NO₃)₃ = concentration x volume

 So;

      Number of moles  = 0.175 x 0.5   = 0.088mol

Now to find the mass;

  Mass  = number of moles x molar mass

      Molar mass of  Fe(NO₃)₃ = 55.8 + 3[14 + 3(16)]

       Molar mass of  Fe(NO₃)₃ = 55.8 + 3(62) = 241.8g/mol

  Mass = 0.088mol x 241.8g/mol  = 21.3g

where is the following

explanation:

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