Answer:
#P: 15
#N: 16
Mass Number: 30.973762u (You can round it if you want)
Isotope symbol: P
Explanation:
I hope this helps :)
Answer:
When Moseley arranged the elements in the periodic table by their number of protons rather than their atomic weights, the flaws in the periodic table that had been making scientists uncomfortable for decades simply disappeared.
Explanation:
Make sure to edit so you don't get copy-writed
Answer:
a) ![\Delta S](https://tex.z-dn.net/?f=%5CDelta%20S%3C0)
b) entropy of the sistem equal to a), entropy of the universe grater than a).
Explanation:
a) The change of entropy for a reversible process:
![\delta S=\frac{\delta Q}{T}](https://tex.z-dn.net/?f=%5Cdelta%20S%3D%5Cfrac%7B%5Cdelta%20Q%7D%7BT%7D)
![\Delta S=\frac{Q}{T}](https://tex.z-dn.net/?f=%5CDelta%20S%3D%5Cfrac%7BQ%7D%7BT%7D)
The energy balance:
![\delta U=[tex]\delta Q- \delta W](https://tex.z-dn.net/?f=%5Cdelta%20U%3D%5Btex%5D%5Cdelta%20Q-%20%5Cdelta%20W)
If the process is isothermical the U doesn't change:
![0=[tex]\delta Q- \delta W](https://tex.z-dn.net/?f=0%3D%5Btex%5D%5Cdelta%20Q-%20%5Cdelta%20W)
![\delta Q= \delta W](https://tex.z-dn.net/?f=%5Cdelta%20Q%3D%20%5Cdelta%20W)
![Q= W](https://tex.z-dn.net/?f=Q%3D%20W)
The work:
![W=\int_{V1}^{V2}P*dV](https://tex.z-dn.net/?f=W%3D%5Cint_%7BV1%7D%5E%7BV2%7DP%2AdV)
If it is an ideal gas:
![P=\frac{n*R*T}{V}](https://tex.z-dn.net/?f=P%3D%5Cfrac%7Bn%2AR%2AT%7D%7BV%7D)
![W=\int_{V1}^{V2}\frac{n*R*T}{V}*dV](https://tex.z-dn.net/?f=W%3D%5Cint_%7BV1%7D%5E%7BV2%7D%5Cfrac%7Bn%2AR%2AT%7D%7BV%7D%2AdV)
Solving:
![W=n*R*T*ln(V2/V1)](https://tex.z-dn.net/?f=W%3Dn%2AR%2AT%2Aln%28V2%2FV1%29)
Replacing:
![\Delta S=\frac{n*R*T*ln(V2/V1)}{T}](https://tex.z-dn.net/?f=%5CDelta%20S%3D%5Cfrac%7Bn%2AR%2AT%2Aln%28V2%2FV1%29%7D%7BT%7D)
![\Delta S=n*R*ln(V2/V1)}](https://tex.z-dn.net/?f=%5CDelta%20S%3Dn%2AR%2Aln%28V2%2FV1%29%7D)
Given that it's a compression: V2<V1 and ln(V2/V1)<0. So:
![\Delta S](https://tex.z-dn.net/?f=%5CDelta%20S%3C0)
b) The entropy change of the sistem will be equal to the calculated in a), but the change of entropy of the universe will be 0 in a) (reversible process) and in b) has to be positive given that it is an irreversible process.
Answer:
Molar concentration of HCl = 0.279 M
Explanation:
Given data:
Volume of NaOH = 31.00 mL ( 31/1000 = 0.031 L)
Molarity of NaOH = 0.0900 M
Volume of HCl = 10.00 mL (0.01 L)
Molar concentration of HCl = ?
Solution:
Chemical equation:
NaOH + HCl → NaCl + H₂O
Number of moles of NaOH:
Number of moles = Molarity × volume in L
Number of moles = 0.0900 mol/L × 0.031 L
Number of moles = 0.00279 mol
For one mole of HCl one mole of NaOH is required.
Number of moles of HCl = 0.00279 mol
Molar concentration of HCl = 0.00279 mol / 0.01 L
Molar concentration of HCl = 0.279 M
I would say D but overall it would actually be all of the above :)