Answer:The copper chloride did not fully dissolve in water before performing the reaction.
The mass of the copper was not measured with the same accuracy.
Not all of the copper was collected in the filter.
Not enough time was allowed for all of the aluminum to react.
There were impurities in the aluminum.
I'll be using dimensional analysis to help out.
2.5mol Na2O * ( X gNa2O / 1 molNa2O) = ? gNa2O
X gNa2O is the molar mass of the molecule. To find that we must add up the molar masses of all of the elements in the molecule.
There are 2 Na (Sodium).
And 1 O (Oxygen).
The Molar Mass of Na = 2 * 22.99 g/mol (It's multiplied by 2 because there are 2 of them in the molecule)
The Molar mass of O = 16.00 g/mol
If you are confused on where I found them. Let me enlighten you! I found them from a periodic table of elements.
Add those two values together to get a total molecular molar mass of:
38.99g/mol
2.5mol Na2O * ( 38.99 gNa2O / 1 molNa2O) = 97 gNa2O
The answer that is most likely true about ocean temperatures surrounding Australia, which is marked by the star in the following map is that b) the ocean temperatures north of Australia are higher than the ocean temperatures south of Australia.
Intertidal zone is the shallowest part of the ocean ecosystem, where the ocean floor os covered and uncovered as the tide goes in and out