The density of ice is less than the density of water (liquid). We generally observe that the density of a solid substance is more than its liquid form as volume of a solid is generally less than the liquid, However in case of water this is not true.

The volume of ice is less than that of liquid water due to an open cage like structure in ice which gives its a wide structure. This cage like structure is due to presence of hydrogen bond (more extensive) in ice.

The maximum density of water is observed at 4 degree celsius

5 0

3 years ago

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

vitfil [10]

The composition in mol% of the elements are :

4.91% of Al₂O₃ in alloy
95.08% of Cu in alloy

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.

Learn more about alloys : brainly.com/question/716507

4 0

3 years ago