Answer:
0.132 meters is the wavelength of sounds to which people are most sensitive.
Explanation:
Frequency of the sound human ears are most sensitive to = 
Speed of the sound wave = S = 330 m/s
Wavelength of the sound human ears are most sensitive to = 
0.132 meters is the wavelength of sounds to which people are most sensitive.
Answer:
-252.5 kJ/mol = ΔH H2O(g)
Explanation:
ΔH Fe2O3 = -825.5kJ/mol
ΔH H2 = 0kJ/mol
ΔH Fe = 0kJ/mol
Based on Hess's law, ΔH of a reaction is the sum of ΔH of products - ΔH of reactants. For the reaction:
Fe2O3(s) + 3 H2(g) →2Fe(s) + 3 H2O(g)
ΔHr = 67.9kJ/mol = 3*ΔH H2O + 2*ΔHFe - (ΔH Fe2O3 + 3*Δ H2)
67.9kJ/mol = 3*ΔH H2O + 2*0kJ/mol - (ΔH -825.5kJ/mol + 3*Δ H2)
67.9 = 3*ΔH H2O(g) + 825.5kJ/mol
-757.6kJ/mol = 3*ΔH H2O(g)
<h3>-252.5 kJ/mol = ΔH H2O(g)</h3>
Answer : Option B) Row 1, Volume decreases when pressure increases.
Explanation : According to the boyle's law, when the pressure of the gas molecules are increased from 2 atm to 3 atm creates a decrease in volume of the gas which then increases the rate of collision of the molecules and makes it more compact than it was before.
Option D.
A voltaic cell need tha anode, the cathode and the electrolyt to work.
Volitmeter is just an equipment to measure the functioning of the voltaic cell.
I believe it is C. I hope
