Answer:
reaction B
Explanation:
From Arrhenius equation
k=A e-Ea/RT
Where
K= rate constant
Ea= activation energy
R= universal gas constant
T= temperature in kelvin
A= frequency factor
The higher the activation energy, the lower the value of e-Ea/RT. If A is constant for reaction A and B, then the reaction with lower activation energy will have a higher value of rate constant, k because e-Ea/RT will have a higher value. Hence reaction B having a greater activation energy will have a smaller value of rate constant k.
if O is -2 and hydrogen +1 then phosphorus is +5
What this tells you is that the oxidation number of P in phosphorus acid must be +3 or +4, while the value for phosphoric acid must be +5 or +6. Since phosphorus is a member of group 5A, it has 5 electrons in its valence shell. As a result, the most common oxidation states it can have are +3 (s2p0) or +5 (s0p0).
So far we have determined the oxidation state at P. What needs to be done now is to add as many oxygens and hydroxyl (OH) to make the molecule neutral. The correct combination will have the correct Lewis-dot structure. For phosphorous acid we need a combination that will add up to +3. This can be done by adding 3 OH- to the central atom to yield the structure H3PO3. There is a little caveat though. Because this is not a hydro___acid, it is implied that there must be at least one oxo ligand (O^2-) bonded to P. Therefore, the actual bonding structure is not P(OH)3 but rather H-P(=O)(OH)2, where one H is bonded directly to the phosphorus atom and is the least acidic of the protons. The great thing is that the oxidation charge of P is still +3 because P is slightly more electronegative than H (some theories will say otherwise); thus the hydrogen is regarded as H+ for this example.
With phosphoric acid, charge of +5, you can have 3 OH- and 1 O^2- to make a neutral molecule:
O=P(OH)3.
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I choose the option A.
The electron absorbs energy from specific wavelength then moving from a lower energy orbital to a higher energy orbital.
Answer:
A solution of acetic acid that is 60.0% HC₂H₃O₂ (by mass) indicates that it contains 60.0 g of acetic acid and 100.0 g of water.
Explanation:
A percentage is a way of expressing an amount as a fraction of 100. The mass percentage corresponds to physical units of the solutions and they allow to establish more precisely the concentration of the solutions and express them in terms of percentages.
Mass percentage indicates the amount in grams of solute per 100 grams of solution.
So a solution of acetic acid that is 60.0% HC₂H₃O₂ (by mass) indicates that it contains 60.0 g of acetic acid and 100.0 g of water.
Answer:
the final temperature is T=305.63 K
Explanation:
using the Stephan-Boltzmann equation for black bodies
q = σ*(T⁴-T₀⁴)
where
q= heat flux = 155 W/m²+150 W/m² = 255 W/m²
σ= Stephan-Boltzmann constant = 5.67*10⁻⁸ W/m²K⁴
T= absolute temperature
T₀= absolute initial temperature = 255 K
solving for T
q = σ*(T⁴-T₀⁴)
T = (q/σ + T₀⁴)^(1/4)
replacing values
T = (q/σ + T₀⁴)^(1/4) = (255 W/m²/(5.67*10⁻⁸ W/m²K⁴) + (255 K)⁴)^(1/4) = 305.63 K
T=305.63 K
thus the final temperature is T=305.63 K