Finding the empirical formula of iron oxide?

Sam and Bob are conducting an investigation to determine the empirical formula of iron oxide. They start with an 85.65g piece of iron metal and burn it in air. The mass of the iron oxide produced is 118.37g. Sam thinks the empirical formula of iron oxide is Fe3O4 and Bob thinks it is FeO. Use what you know about how to determine the empirical formula of a compound.

Answer 1

#"Fe"_3"O"_4#

Accordingly, the mass of oxygen will be represented by the difference between the mass of the product and the mass of iron, assuming that the entire mass of iron participated in the reaction.

#m_"product" = m_"iron" + m_"oxygen"#
#m_"oxygen" = "118.37 g" - "85.65 g" = "32.72 g"#

You can calculate the number of moles of each element using the molar masses of the two elements now that you know how much iron and how much oxygen are present in the iron oxide.

Regarding iron, you will possess

#85.65color(red)(cancel(color(black)("g"))) * "1 mole Fe"/(55.845color(red)(cancel(color(black)("g")))) = "1.534 moles Fe"#

In terms of oxygen, you will have

#32.72color(red)(cancel(color(black)("g"))) * "1 mole O"/(16.0color(red)(cancel(color(black)("g")))) = "2.045 moles O"#

The smallest whole number ratio between the two components of the compound must be found in order to obtain the empirical formula for iron oxide.

Divide both values by the smallest one to achieve that.

#"For Fe: " (1.534color(red)(cancel(color(black)("moles"))))/(1.534color(red)(cancel(color(black)("moles")))) = 1#
#"For O: " (2.045color(red)(cancel(color(black)("moles"))))/(1.534color(red)(cancel(color(black)("moles")))) = 1.333#
To get the smallest whole number ratio that exists between the two elements, multiply both values by #color(blue)(3)#. This will help you get rid of the decimal fraction for oxygen.

Thus, the iron oxide empirical formula will be

#("Fe"_1"O"_1.333)_color(blue)(3) implies color(green)("Fe"_3"O"_4)#
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Answer 2

Fe2O3 is the empirical formula for iron oxide.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

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