4
N
a
+
O
2
→
2
N
a
2
O
.
By the stoichiometry of this reaction if 5 mol natrium react, then 2.5 mol
N
a
2
O
should result.
Explanation:
The molecular mass of natrium oxide is
61.98
g
⋅
m
o
l
−
1
. If
5
m
o
l
natrium react, then
5
2
m
o
l
×
61.98
g
⋅
m
o
l
−
1
=
154.95
g
natrium oxide should result.
So what have I done here? First, I had a balanced chemical equation (this is the important step; is it balanced?). Then I used the stoichiometry to get the molar quantity of product, and converted this molar quantity to mass. If this is not clear, I am willing to have another go
Activation energy is the energy required by reactants to undergo chemical reaction and given products
Every reactant has some internal energy (sum of all kind of energy like kinetic energy, potential energy, mechanical energy, chemical energy etc). It needs some extra energy to undergo chemical reaction which is activation energy
All kinds of reaction whether exothermic or endothermic needs activation energy
Threshold energy = internal energy + activation energy
Answer:
Heat and mass transfer of a LiBr/water absorption heat pump system (AHP) was experimentally studied during working a heating-up mode. The examination was performed for a single spiral tube, which was simulated for heat transfer tubes in an absorber. The inside and outside of the tube were subjected to a film flow of the absorption liquid and exposed to the atmosphere, respectively. The maximum temperature of the absorption liquid was observed not at the entrance but in the region a little downward from the entrance in the tube. The steam absorption rate and/or heat generation rate in the liquid film are not constant along the tube. Hence the average convective heat transfer coefficient between the liquid film flowing down and the inside wall of the tube was determined based on a logarithmic mean temperature difference between the tube surface temperature and the film temperature at the maximum temperature location and the bottom. The film heat and mass transfer coefficients rose with increasing Reynolds number of the liquid film stream.
Answer:
C. 75%
Explanation:
From a heterozygous cross (Tt x Tt) the produced offspring would consist of:
- 25% TT -it would be tall-.
- 50% Tt -it would be tall as the gene T is dominant-.
- 25% tt -it would not be tall-.
Thus the produced offspring that would be tall is (50% + 25%) 75%. The answer is option C.
