How is counting a truckload of pennies like counting the atoms in 10.0 g of aluminum? How is it different?
1 answer:
Answer:
Explanation:
A truckload of pennies is quite a very large amount of problem to solve. A truck can carry a lot of coins which can be up to several millions in number approximately.
This is similar to counting the number of atoms in 10.0g of aluminium.
In a mole of any substance, there are 6.02 x 10²³ atoms.
number of moles =
molar mass of Al = 27g/mole
number of moles = = 0.37moles
Number of atoms = 0.37 x 6.02 x 10²³ = 2.23 x 10²³ atoms
In 10g of aluminium, there are 2.23 x 10²³ atoms. It is even much more tedious to count.
Difference;
We can see the pennies in the truckload. They are discrete. It is impossible to see atoms in a substance this way.
Also, the number of atoms in 10g of aluminium is more than that of pennies in a truckload.
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The correct answer is option C, 5.02 x 10²² carbon atoms
Atomic mass of C = 12 g/mol
According to Avogadro, 1 mole of C has 6.023 x 10²³C atoms
Now 1 mole of C is equal to 12 g
Therefore, 12 g of C = 6.023 x 10²³ C atoms
1 g of C = C atoms = 5.02 x 10²² C atoms
Answer:
0.15g
Explanation:
Given parameters:
Number of molecules of water = 1.2 x 10²¹ molecules
Unknown:
Mass of SnO₂ = ?
Solution:
To solve this problem, we have to work from the known to the unknown specie;
SnO₂ + 2H₂ → Sn + 2H₂O
Ensure that the equation given is balanced;
Now,
the known species is water;
6.02 x 10²³ molecules of water = 1 mole
1.2 x 10²¹ molecules of water = = 0.2 x 10⁻²moles
Number of moles of water = 0.002moles
From the balanced chemical equation:
2 mole of water is produced from 1 mole of SnO₂
0.002 moles of water will be produced from = 0.001moles
To find the mass;
Mass = number of moles x molar mass
Molar mass of SnO₂ = 118.7 + 2(16) = 150.7g/mol
Mass = 0.001 x 150.7 = 0.15g