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
Yes it’s correct.
An ionic bond is the transfer of electrons from a metal to a non-metal.
Step 1:
Write molecular Formula,
Na₅P₃O₁₀
Step 2:
Assign Oxidation number to Na (which is +1) and O (which is -2), and X (unknown) for P.
(+1)₅ + (X)₃ + (-2)₁₀ = 0
Zero means overall charge on molecule is zero (Neutral).
Step 3:
Now solve for X,
(+5) + (X ÷ 3) + (-20) = 0
X ÷ 3 = -5 + 20
X ÷ 3 = +15
X = +15 ÷ 3
X = +5
Result:
Oxidation number of P is +5.
Answer:
250ml
Explanation:
call it V
V*0.2=0.05 (moles)
so V=0.05/0.2 = 0.25l = 250ml
