From equation;
P1V1=P2V2
V2=P1V1÷P2
since P2=380mmHg
now;1atm=760mmHg
how about 380mmHg is equal to how many atm?
380×1÷760=0.5atm
P2 now is equal to 0.5atm
back from equation;
P1V1=P2V2
V2=P1V1÷P2
V2=4.0atm×2.0L÷0.5atm
V2=16L
therefore V2=16L.
Answer:
The molar concentration of Cu²⁺ in the initial solution is 6.964x10⁻⁴ M.
Explanation:
The first step to solving this problem is calculating the number of moles of Cu(NO₃)₂ added to the solution:

n = 1.375x10⁻⁵ mol
The second step is relating the number of moles to the signal. We know the the n calculated before is equivalent to a signal increase of 19.9 units (45.1-25.2):
1.375x10⁻⁵ mol _________ 19.9 units
x _________ 25.2 units
x = 1.741x10⁻⁵mol
Finally, we can calculate the Cu²⁺ concentration :
C = 1.741x10⁻⁵mol / 0.025 L
C = 6.964x10⁻⁴ M
I uploaded the answer to a file hosting. Here's link:
tinyurl.com/wtjfavyw
Hey there!:
The fractional saturation y is defined as :
y = [ L ] / Kd + [ L ]
where :
[ L ] = concentration of binding ligand
Kd = 400 nm
To solve the question you use the following formula:
concentration (1) × volume (1) = concentration (1) × volume (1)
3 M × volume (1) = 1.8 M × 50 mL
volume (1) = (1.8 M × 50 mL) / 3 M = 30 mL