Answer:
1.9×10^20
Explanation:
ϕ = number of reaction events /number of photons absorbed
ϕ= 0.26
Energy= power× time
885×10^-3×10×60= 531J
But E= nhc/λ
n= number of photons
h= planks constant
c= speed of light
λ= wavelength
n= Eλ/hc
n= 531×280×10^-9/6.6×10^-34 ×3×10^8
n= 7.5×10^20
Therefore
From
ϕ = number of reaction events /number of photons absorbed
Number of reaction events= 0.26×7.5×10^20
= 1.95×10^20
Answer:
Protons and neutrons which packed tightly into central core of the atom.
Explanation:
Atoms are composed of three subatomic particle; electron, proton and neutron. Electrons are negatively charged, protons are positively charged whereas neutrons are neutral, hence does not have any charge.
Out of three, protons and neutrons are present in the nucleus of the atom.
Nucleus is the central part of the atom possessing most of the mass of the atom. In the nucleus, protons and neutrons are tightly packed with the help of nuclear force.
Electrons are present around the nucleus also called electron cloud.
Therefore, nucleus are composed of protons and neutrons which packed tightly into central core of the atom
Answer:
No, it is not feasible because the Gibbs free energy change is positive
Explanation:
∆Hreaction= (-602 KJ/mol) - (-348 KJ/mol) = -254 KJ/mol
∆Sreaction = (42 + 27) J/Kmol - (33 + 44) J/K = -8J/Kmol
From;
∆G = ∆H - T∆S
∆G = 254 × 10^3 J/mol - [340K × (-8 J/Kmol)]
∆G = 2.57 × 10^5 J/mol
Note that when the change in free energy is positive, a reaction is non spontaneous. Only a reaction that has a negative change in free energy is spontaneous.
Explanation:
I think the answer is B ♂️ but I'm not sure
Answer:
65.4%
Explanation:
The redox reaction is a 1:1:1 reaction because the reagents suffer a double displacement reaction, and the substance that is substituted have the same charge (H+ and Br-), thus, we first need to know which of the reagents is the limiting.
Let's test the 4-nitrobenzaldehyde as the limiting. The mass needed for sodium borohydride (m) is the mass given of 4-nitrobenzaldehyde multiplied by the stoichiometric mass of sodium borohydride divided by the stoichiometric mass of 4-nitrobenzaldehyde. The stoichiometric mass is the number of moles in the stoichiometric representation (1:1:1) multiplied by the molar mass, so:
m = (4.13 * 37.83*1)/(151.12*1)
m = 1.034 g
So, the mass needed of the other reagent is larger than the mass that was given, so, it will be the limiting, and the stoichiometric calculus must be done with it.
The mass of the product that was expected is then:
m = (0.700*153.14*1)/(37.83*1)
m = 2.83 g
The percent yield is the mass that was formed divided by the expected mass, and then multiplied by 100%:
%yield = (1.85/2.83)*100%
%yield = 65.4%
