In a 1.143E+2 g sample of iron(III) oxide, how many grams of iron are present? Your answer should have the appropriate number of significant figures (use two decimal places in atomic masses).

Respuesta :

Mass of iron(III)oxide, Fe2O3 sample = 1.143*10^2 g

Molar mass of Fe2O3 = 159.69 g/mole

i.e. 1 mole of Fe2O3 weighs 159.69 g

Based on stoichiometry:

1 mole of Fe2O3 has 2 moles of Fe

Atomic mass of Fe = 55.85 g/mole

Therefore we can write:

159.69 g of Fe2O3 is composed of 2*55.85 g of Fe

Thus, amount of Fe present in 1.143*10^2 g sample of Fe2O3 is

= 1.143*10^2 * 2* 55.85/159.69

= 7.995*10^-1 g

79.86 grams of iron are present in 1.143×10²g sample of iron(III) oxide Fe₂O₃.

How we calculate mass from?

Mass of any substance can be calculated by using their moles as:

n = W/M, where

W = given mass

M = molar mass

According to the stoichiometry:

1 mole of Fe₂O₃ = contain 2 mole of Fe

In the question given that mass of Fe₂O₃ = 1.143×10²g

Mole of Fe₂O₃ = 1.144×10²g / 159.69 g/mole = 0.715mole

0.715 mole of Fe₂O₃ = contain 2×0.715 mole of Fe

So, mole of Fe = 1.43 mole

Now required mass of Fe will be calculated by using the above formula of mole as:

W = n × M

W = 1.43mole × 55.85g/mole = 79.86g

Hence, 79.86g of iron are present.

To know more about moles, visit the below link:

https://brainly.com/question/14464650

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