Answer:
On the Moh's scale of hardness, aluminum oxide is positioned just below to diamond due to which it is considered as one of the hardest known compounds. This also shows that the compound exhibit an enormous amount of lattice energy, as to transform the oxide into its constituent ions, the energy is required to overcome.
Based on the chemical formula of the compound, that is, Al2O3, it is shown that the ions of Al3+ and O2- are kept close due to the activity of the strong electrostatic ionic bonds. The electrostatic forces and the ionic bonding between the ions are extremely robust due to the presence of the ions high charge density. Therefore, to dissociate the bonds, an enormous amount of energy is needed, and at the same time, a high amount of lattice energy is present.
Answer:
H₂ gas
Explanation:
The reaction between nitrogen gas and hydrogen gas forms ammonia (the Haber-Bosch process):
N₂ + 3H₂ ⇒ 2NH₃
The excess reactant can be found by comparing the moles of nitrogen and hydrogen. The molar mass of N₂ is 28.00 g/mol and the molar mass of H₂ is 2.02 g/mol.
(100 kg N₂)(1000g/kg)(mol/28.00g) = 3570 mol
(100 kg H₂)(1000g/kg)(mol/2.02g) = 49500 mol
The molar ratio between the reactant N₂ and H₂ is 1N₂:3H₂. The moles of nitrogen required to react with H₂ is:
(49500 mol H₂)(1N₂ / 3H₂) = 16500 mol
The amount of nitrogen required is more than what is available, so nitrogen is the limiting reagent and hydrogen is the excess reagent.
Cu (s) + 2AgNO3 ---> 2Ag + Cu(NO3)2
=13.5 moles Silver Nitrate
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.
Answer:
D
Explanation:
Solar panels are not toxic, so option A goes out the window.
Aesthetics don't really matter, so option B follows it out.
Option C makes a little sense, but less so than Option D. They aren't nearly as heavy as some of our current energy production methods.
Solar panels are expensive, hard to store properly, and most are between 15 and 20 percent efficiency, compared with a diesel motor's 40 percent.
