Answer:
75603.86473 K
Explanation:
Given that:
The 1st excited electronic energy level of He atom = 3.13 × 10⁻¹⁸ J
The objective of this question is to estimate the temperature at which the ratio of the population will be 5.0 between the first excited state to the ground state.
The formula for estimating the ratio of population in 1st excited state to the ground state can be computed as:
From the above equation:
Δ E = energy difference = 3.13 × 10⁻¹⁸ J
k = Boltzmann constant = 1.38 × 10⁻²³ J/K
Thus:
T = 75603.86473 K
When a volume of 60.0 mL of 0.200 M HBr is mixed with a volume of 30.0 mL of 0.400 M CH3NH2, The pH value is mathematically given as
pH=10.64
<h3>What is
the pH value when 60.0 mL of 0.200 M HBr is mixed with 30.0 mL of 0.400 M CH₃NH₂?</h3>
Question Parameters:
The pH when 60.0 mL of 0.200 M HBr
30.0 mL of 0.400 M CH₃NH₂ (Kb = 4.4 × 10^{-4}).
Generally, the equation for the Chemical Reaction is mathematically given as
H Br + H_3C NH_2----- > CH_3 NH_3 Br
Therefore
oH=p^{kb}+-log
OH=-log(4.4*10^{-4})+
OH=3.36
In conclusion, The equation pH value
pH+OH=14
Therefore
pH+=14-3.36
pH=10.64
Read more about Chemical Reaction
brainly.com/question/11231920
solution:
The quoted atomic mass on the Periodic Table is the WEIGHTED average of the individual isotopic masses. The higher the isotopic percentage, the MORE that isotope will contribute to the isotopic mass. For this reason, most masses that are quoted on the Table are non-integral.
By way of example we could look to the hydrogen atom. The VAST majority of hydrogen atoms (in this universe) are the protium isotope. i.e. 1H, whose nuclei contain JUST the defining proton. There is a smaller percentage (>1%) of hydrogen atoms WITH one NEUTRON in their nuclei to give the deuterium isotope. i.e. 2H, and because this is relatively cheap, and easily incorporated into a molecule, deuterium labelling is routinely used in analysis.
And there is even a smaller percentage of hydrogen atoms with TWO NEUTRONS in their nuclei, to give the tritium isotope. i.e. 3H. The weighted average of the isotopic percentages gives 
Answer: pH of HCl =5, HNO3 = 1,
NaOH = 9, KOH = 12
Explanation:
pH = -log [H+ ]
1. 1.0 x 10^-5 M HCl
pH = - log (1.0 x 10^-5)
= 5 - log 1 = 5
2. 0.1 M HNO3
pH = - log (1.0 x 10 ^ -1)
pH = 1 - log 1 = 1
3. 1.0 x 10^-5 NaOH
pOH = - log (1.0 x 10^-5)
pOH = 5 - log 1 = 5
pH + pOH = 14
Therefore , pH = 14 - 5 = 9
4. 0.01 M KOH
pOH = - log ( 1.0 x 10^ -2)
= 2 - log 1 = 2
pH + pOH = 14
Therefore, pH = 14 - 2 = 12
Answer:this case, the mass is 2.0g, the specific heat capacity of water is 4.18J/g/K, and the change in temperature is 5.0°C=5K , therefore the energy needed to raise it is: 5×2×4.18=41.8J
Explanation:
