Answer:
PREVIEW
2:15
How to Draw the Bohr-Rutherford Diagram of Magnesium
chemistNATE
Jul 23, 2019
Explanation:
<span>In the laws of mathematics, especially in rounding off digits, you
should take note of the digit following that number no matter how long or short
a number is. If the numberis preceded by numbers between 0-4, the number does
not change. However if its is preceded by numbers between 5-9, add one to the
number. For example, 145698. If it is rounded off to the nearest hundreds,
since 9 is the number after 6, add 1 to 6 and it becomes 145700. If it is
rounded off to the nearest hundred thousands, since 4 is the number after 1,
you do not add, the number stays the same and it becomes 100000</span>
Answer:
% oxygen = 47.1 %
% aluminium = 52.9 %
Explanation:
Step 1: Data given
Mass of aluminium = 2.70 grams
Mass of aluminium oxide = 5.10 grams
Step 2: The balanced equation
4Al + 3O2 →2Al2O3
Step 3: Calculate mass of oxygen
The law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products.
Mass oxygen + mass aluminium = mass aluminium oxide
Mass oxygen + 2.70 grams = 5.10 grams
Mass oxygen = 5.10 grams - 2.70 grams
Mass oxygen = 2.40 grams
Step 4: Calculate percent composition
% oxygen = (mass oxygen / mass aluminium oxide) * 100 %
% oxygen = (2.40 grams / 5.10 grams ) * 100 %
% oxygen = 47.1 %
% aluminium = (mass aluminium / mass aluminium oxide)
% aluminium = (2.70 grams / 5.10 grams ) * 100 %
% aluminium = 52.9 %
47.1 % + 52.9 % = 100 %