Answer:
B.Bronze is harder than copper, so it retains a cutting edge sharper than that of copper.
Explanation:
The importance of bronze in the history of the human kind can not be only measured in the durability but the help that it provided to our ancestors, the things they were allowed to do once they dicovered how to mold it, and the tools that they produced and made many every day tasks easier for them and the ability of bronze to mantain the cutting edge longer than copper was one of the main reasons why it took its places in the fabrication of many tools.
2.6394*10^22 is the answer
Endothermic...a reaction that absorbs heat. That it is why it feels cold to the touch, it is absorbing heat away from the surface of your skin.
1 mole of any gas occupies a volume of 22.4L, therefore there are 3.022×10^24 molecules of oxygen gas in 113.97 L
Answer:
A and C are true , B and D are false
Explanation:
For A)
from the first law of thermodynamics (in differential form)
dU= δQ - δW = δQ - PdV
from the second law
dS ≥ δQ/T
then
dU ≤ T*dS - p*dV
dU - T*dS + p*dV ≤ 0
from the definition of Gibbs free energy
G=H - TS = U+ PV - TS → dG= dU + p*dV + V*dp - T*dS - S*dT
dG - V*dp + S*dT = dU - T*dS + p*dV ≤ 0
dG ≤ V*dp - S*dT
in equilibrium, pressure and temperature remains constant ( dp=0 and dT=0). Thus
dG ≤ 0
ΔG ≤ 0
therefore the gibbs free energy should decrease in an spontaneous process → A reaction with a negative Gibbs standard free energy is thermodynamically spontaneous under standard conditions
For B) Since the standard reduction potential is related with the Gibbs standard free energy through:
ΔG⁰=-n*F*E⁰
then, when ΔG⁰ is negative , E⁰ is positive and therefore a coupled redox reaction with a positive standard reduction potential is thermodynamically spontaneous.