Mass of MnO2 = 25 g
The reaction would be 3MnO2 + 4Al --> 3Mn(s) + 2Al2O3
Molar mass of Al = 26.982 g/mol
Molar mass of MnO2 = 54.938 + 2(15.999) = 86.936 g/mol
Calculating the moles = 25 / 86.936 = 0.2876 mol.
Mole ratio MnO2 and Al considering the equation = 3 mol of MnO : 4 mol of Al
Calculating the moles of Al = 0.2876 mol MnO2 x (4 mol of Al / 3 mol of MnO)
Number of moles of Al = 0.3834
Getting the mass in grams as asked = 0.3834 mol x 26.982 g/mol = 10.34 grams.
We find the weight of the empirical formula:
12.0107 + 2 x 1.00794 + 15.9994
= 30.03
Now, we divide the molecular weight by the weight of the empirical formula to find the number of times the empirical formula repeats:
90.09 / 30.03
= 3
The formula is 3(CH₂O)
C₃H₆O₃
Base isolation is a method of earthquake resistant engineering where a structure is separated from the ground by isolation units that reduces the impact of seismic vibration energy. So, the last answer choice would be the best definition.
1.59 moles
112211111111111112
