Answer:
A. 1.63g/dm^3 (3 s.f.)
B. 0.833g/dm^3 (3 s.f.)
C. 1.92g/dm^3 (3 s.f.)
Explanation:
Please see attached picture for full solution.
Based on Beer-Lambert's Law,
A = εcl ------(1)
where A = absorbance
ε = molar absorptivity
c = concentration
l = path length
Step 1: Calculate the concentration of the diluted Fe3+ standard
Use:
V1M1 = V2M2
M2 = V1M1/V2 = 10 ml*6.35*10⁻⁴M/55 ml = 1.154*10⁻⁴ M
Step 2 : Calculate the concentration of the sample solution
Based on equation (1) we have:
A(Fe3+) = ε(1.154*10⁻⁴)(1)
A(sample) = ε(C)(4.4)
It is given that the absorbances match under the given path length conditions, i.e.
ε(1.154*10⁻⁴)(1) = ε(C)(4.4)
C = 0.262*10⁻⁴ M
This is the concentration of Fe3+ in 100 ml of well water sample
Step 3: Calculate the concentration of Fe3+ in the original sample
Use V1M1 = V2M2
M1 = V2M2/V1 = 100 ml * 0.262*10⁻⁴ M/35 ml = 7.49*10⁻⁵M
Ans: Concentration of F3+ in the well water sample is 7.49*10⁻⁵M
Answer:
from south to north thats what it look like
Explanation:
Rare earth elements are a series of chemical elements found in the earth's crust and are vital to many of the modern technologies in the world such as computers and networks, advanced transportation and consumer electronics. They help fuel economic growth, maintain high living standards and even save lives. Examples include:
Scandium. Used in television and fluorescent lamps.
Yttrium. Used in cancer treatment drugs, superconductors and camera lenses
Lanthanum. Used to make special optical glasses, telescope lenses and also in petroleum refining.
Neodymium. Used in making some of the strongest permanent magnets, found in most modern vehicles and aircraft.
