You can use mole ratios and molar mass to determine the masses of substances involved in a chemical reaction. using the periodic table, calculate the molar masses of iron oxide (fe2o3) and aluminum oxide (al2o3). give your answer to four significant figures.

Answer : Molar mass of the is 159.7 g/mol.

Molar mass of the is 101.96 g/mol.

Explanation:

Molar mass of :

Molar mass =

Molar mass of the is 159.7 g/mol

Molar mass of :

Molar mass =

Molar mass of the is 101.96 g/mol

The molar mass of Fe2O3 and Al2O3  is 160.0 g/mol and 102.0 g/mol respectively.

The molar mass of a compound is the addition of the molar weights of the individual atoms that make up the compound.

In this case, the molar weight of Fe is 56, O is 16, and Al is 27 g/mol respectively.

Fe2O3 = (56x2) + (16x3)

              = 160.0 g/mol

Al2O3 = (27x2) + (16x3)

            = 102.0 g/mol

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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