At least, that's what Bohr<span> decided, and that's why he proposed the </span>existence<span> of the</span>atomic<span> energy level. </span>According<span> to </span>Bohr<span>, the electrons in an </span>atom<span> were only allowed to </span>exist<span> at certain energy levels</span>
Answer:
1.72x10⁻⁵ g
Explanation:
To solve this problem we use the PV=nRT equation, where:
- R = 0.082 atm·L·mol⁻¹·K⁻¹
- T = 25 °C ⇒ (25+273.16) = 298.16 K
And we <u>solve for n</u>:
- 1 atm * 5.7x10⁶ L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K
Finally we <u>convert moles of helium to grams</u>, using its <em>molar mass</em>:
- 4.29x10⁻⁶ mol * 4 g/mol = 1.72x10⁻⁵ g
Answer:
Explanation:
CH₃CHOHCOOH ⇄ CH₃CHOHCOO⁻ + H⁺
ionisation constant = 1.36 x 10⁻⁴ .
molecular weight of lactic acid = 90 g
moles of acid used = 20 / 90
= .2222
it is dissolved in one litre so molar concentration of lactic acid formed
C = .2222M
Let n be the fraction of moles ionised
CH₃CHOHCOOH ⇄ CH₃CHOHCOO⁻ + H⁺
C - nC nC nC
By definition of ionisation constant Ka
Ka = nC x nC / C - nC
= n²C ( neglecting n in the denominator )
n² x .2222 = 1.36 x 10⁻⁴
n = 2.47 x 10⁻²
nC = 2.47 x 10⁻² x .2222
= 5.5 x 10⁻³
So concentration of hydrogen or hydronium ion = 5.5 x 10⁻³ g ion per litre .
The solubility equilibrium of PbCl
:
![K_{sp}=[Pb^{2+}][Cl^{-}]^{2}](https://tex.z-dn.net/?f=%20K_%7Bsp%7D%3D%5BPb%5E%7B2%2B%7D%5D%5BCl%5E%7B-%7D%5D%5E%7B2%7D%20%20%20)
![[Cl^{-}] = 2.88 * 10^{-2} M](https://tex.z-dn.net/?f=%20%5BCl%5E%7B-%7D%5D%20%3D%202.88%20%2A%2010%5E%7B-2%7D%20M%20)
![[Pb^{2+}]=\frac{[Cl^{-}]}{2} = \frac{2.88 * 10^{-2}}{2}=1.44 *10^{-2}](https://tex.z-dn.net/?f=%20%5BPb%5E%7B2%2B%7D%5D%3D%5Cfrac%7B%5BCl%5E%7B-%7D%5D%7D%7B2%7D%20%3D%20%5Cfrac%7B2.88%20%2A%2010%5E%7B-2%7D%7D%7B2%7D%3D1.44%20%2A10%5E%7B-2%7D%20%20%20%20)
= 
= 
So, the corrected solubility product will be
