Respuesta :
Answer:
Al 72.61%
Mg 27.39%
Explanation:
To obtain the mass percentages, we need to place the individual masses over the total mass and multiply by 100%.
If we observe clearly, we can see that the parameters given are the moles. We need to convert the moles to mass.
To do this ,we need to multiply the moles by the atomic masses. The atomic mass of aluminum is 27 while that of magnesium is 24.
Now, the mass of aluminum is thus = 27 * 0.0898 = 2.4246g
The mass of magnesium is 0.0381 * 24 = 0.9144g
We can now calculate the mass percentage.
The total mass is 0.9144 + 2.4246 = 3.339g
% mass of Al = 2.4246/3.339 * 100 = 72.61%
% mass of Mg = 0.9144/3.39 * 100 = 27.39%
Answer:
Mass % Al = 72.3 %
Mass % Mg = 27.7 %
Explanation:
Step 1: Data given
Number of moles Al = 0.0898 moles
Number of moles Mg = 0.0381 moles
Molar mass Al = 26.98 g/mol
Molar mass Mg = 24.3 g/mol
Step 2: Calculate mass Al
Mass Al = moles Al * molar mass Al
Mass Al = 0.0898 moles * 26.98 g/mol
Mass Al = 2.42 grams
Step 3: Calculate mass Mg
Mass Mg = 0.0381 moles * 24.3 g/mol
Mass Mg = 0.926 grams
Step 4: Calculate total mass
Total mass = mass Al + mass Mg
Total mass = 2.42 grams + 0.926 grams
Total mass = 3.346 grams
Step 5: Calculate mass %
Mass % Al = (mass Al/ total mass) * 100%
Mass % Al = (2.42 grams / 3.346 grams ) *100%
Mass % Al = 72.3 %
Mass % Mg = (mass Mg/ total mass)*100%
Mass % Mg = (0.926 / 3.346) *100 %
Mass % Mg = 27.7 %
