<u>Answer:</u> Maximum work that can be obtained by given amount of methanol is -343kJ.
<u>Explanation:</u>
For the given chemical reaction:
By Stoichiometry of the reaction:
2 moles of methanol does a work of 1372 kJ.
So, 0.5 moles of methanol will do a work of = 
Hence, maximum work that can be obtained by given amount of methanol is -343kJ.
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:
B.bonds are broken and new bonds are formed
Answer: In order to melt a network solid, a relatively large amount of heat is needed, sufficient to break the covalent bonds that hold the entire solid together
hope this helps
Help????? You need to write as if you are Dmitri Mendeleev and you have just made your proposed version of the periodic table. You need to write to the Royal Society of Chemistry in London explaining:
• Who you are
• What your periodic table is like, the groups, elements and features
• Why you think your periodic table is correct
• How you have built on the work of others or why you think their work is not
correct
