Answer:
[H3O+] = 1.0*10^-12 M
[OH-] = 0.01 M
Explanation:
We can use the following equation to find the hydronium ion concentration. Plug in the pH and solve for H3O+.
pH = -log[H3O+]
<u>[H3O+] = 1.0*10^-12 M</u>
Now, to find the hydroxide ion concentration we will use the two following equations.
14 = pH + pOH
pOH = -log[OH-]
14 = 12 + pOH
pOH = 2
2 = -log[OH-]
<u>[OH-] = 0.01 M</u>
Answer:
8.59
⋅
10
17
Explanation:
You can start by figuring out the energy of a single photon of wavelength
505 nm
=
505
⋅
10
−
9
m
.
To do that, use the equation
E
=
h
⋅
c
λ
Here
h
is Planck's constant, equal to
6.626
⋅
10
−
34
.
J s
c
is the speed of light in a vacuum, usually given as
3
⋅
10
8
.
m s
−
1
λ
is the wavelength of the photon, expressed in meters
Plug in your value to find--notice that the wavelength of the photon must be expressed in meters in order for it to work here.
E
=
6.626
⋅
10
−
34
J
s
⋅
3
⋅
10
8
m
s
−
1
505
⋅
10
−
9
m
E
=
3.936
⋅
10
−
19
J
So, you know that one photon of this wavelength has an energy of
3.936
⋅
10
−
19
J
and that your laser pulse produces a total of
0.338 J
of energy, so all that you need to do now is to find how many photons are needed to get the energy output given to you.
0.338
J
⋅
1 photon
3.936
⋅
10
−
19
J
=
8.59
⋅
10
17
photons
−−−−−−−−−−−−−−−−−
The answer is rounded to three sig figs.
Answer:
From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2(s): CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2(g)ΔH∘=−127.2kJ
ΔHf°(C2H2) = 227.4 kJ/mol
ΔHf°(H2O) = -285.8 kJ/mol and
ΔHf°(Ca(OH)2) = -985.2 kJ/mol
(Ans)
ΔHf° of CaC2 = -59.0 kJ/mol
Explanation:
CaC2(s) + 2 H2O(l) → Ca(OH)2(s) + C2H2 (g) = −127.2kJ
ΔHrxn = −127.2kJ
ΔHrxn = ΔHf°(C2H2) + ΔHf°(Ca(OH)2) - ΔHf°(CaC2)- 2ΔHf°(H2O);
ΔHf°(CaC2) = ΔHf°(C2H2) + ΔHf°(Ca(OH)2) - 2ΔHf°(H2O) – ΔHrxn
Where
ΔHf°(C2H2) = 227.4 kJ/mol
ΔHf°(H2O) = -285.8 kJ/mol and
ΔHf°(Ca(OH)2) = -985.2 kJ/mol
ΔHf°(CaC2) =227.4 - 985.2 + 2x285.8 + 127.2 = -59.0 kJ/mol
ΔHf°(CaC2) = -59.0 kJ/mol
This problem is providing us with the mass (70 g), absorbed heat (96 J) and initial and final temperatures (293 K and 313 K, respectively) so the specific heat of the material is required and found to be 0.0686 J/(g*K) as shown below:
<h3>
Calorimetry:</h3>
In chemistry, we can go over calorimetry by writing the following relationship among heat, mass, specific heat and temperature change:
Thus, one can get the specific heat by solving for C in the previous equation:
Hence, we can plug in the given data to obtain:
Learn more about calorimetry: brainly.com/question/1407669
Answer:
Catalyze
Explanation:
Catalysis is defined as<em> the acceleration the of the rate of a chemical reaction</em>, enzymes are natural catalysts that can make more efficient, faster reactions by using less energy and generating less waste.
I hope you find this information useful and interesting! Good luck!