Copper can have improved wear resistance if alloyed with ceramic alumina, Al2O3. If a copper alloy has 7.7 wt % Al2O3, what is i

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3 years ago

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ts composition in mol %?

1 answer:

vitfil [10] · Answer 1 · 2022-12-19T18:54:29+03:00

The composition in mol% of the elements are :

Given data :

Weight percentage of copper alloy = 7.7 wt %

Assume weight of alloy = 100 grams

<h3>Applying the weight percentage </h3>

mass of Al₂O₃ in alloy = 7.7 gm

Mass of Cu in alloy = 100 - 7.7 = 92.3 gm

First step : calculate the mole of elements

i) moles of Al₂O₃ in alloy

= mass of Al₂O₃ in alloy / Atomic mass of Al₂O₃

= 7.7 gm / 102 gm/mol

= 0.075 mol

ii) moles of Cu in alloy

= mass of Cu in alloy / Atomic mass of Cu

= 92.3 gm / 63.5 gm/mol

= 1.45 mol

Therefore the total number of moles in the alloy = 0.075 + 1.45 = 1.525

Next step : Determine the mole percentages

i) Mole percentage of Al₂O₃ in alloy

= ( 0.075 ) / 1.525 * 100

= 4.91%

ii) Mole percentage of Cu in alloy

= ( 1.45 ) / 1.525 * 100

= 95.08%

Hence we can conclude that The composition in mol% of the elements are : 4.91% of Al₂O₃ in alloy and 95.08% of Cu in alloy.