Answer:
Explanation: The lowest pressure in a laboratory is 4.0×10^-11Pa
Using Ideal gas equation
PV = nRT
P= 4.0×10^-11Pa
V= 0.020m^3
T= 20+273= 293k
n=number of moles = m/A
Where m is the number of molecules and A is the Avogradro's number=6.02×10²³/mol
R=8.314J/(mol × K)
PV= m/A(RT)
4.0×10^-11 ×0.020 = m/6.02×10²³(8.314×293)
m = 4.0×10^-11×0.020×6.02×10^23 / (8.314×293)
m = 1.98×10^8 molecules
Therefore,the number of molecules is 1.98×10^8
The sodium ion becomes hydrated. when sodium chloride dissolves in water, the sodium and chloride ions and the polar water molecules are strongly attracted to one another by ion-dipole interactions
Answer:
The answer to your question is 12
Explanation:
Data
Number of electrons in Phosphorus 3+ ion
Process
1.- The sign of the number after the name indicates if the element has lost or gained electrons.
If the sign is positive the element has lost electrons
If the sign is negative the element has gained electrons.
2.- Phosphorus atomic number is 15, then the number of electrons in Phosphorus 3+ will be 12, in this example, Phosphorus lost 3 electrons.
Answer:
0.1795 M
Explanation:
From the given information:
The equation is:
From the above equation, the reaction will go to completion due to the strong base:
At the equivalence point, moles of acid (HF) will be equal to moles of base (KOH)
Thus. since moles of HF = moles of KOH
Then; 0.020 × 0.393 M = 0.02379 × (x) M
(x) M = 
(x) = 0.3304 M
Thus, the molarity of KOH = 0.3304 M
Using the balanced neutralization reaction;
moles of HF = moles of KOH = moles of conjugate base = 0.00786 mol
∴
Volume = 0.020 L + 0.02379 L
Volume = 0.04379 L
Volume of the solution = 0.04379 L
Therefore; Molarity = 
Molarity = 
Molarity = 0.17949 mol/L
= 0.1795 M
