Question

In chemistry lab student is determining the salinity of seawater using a conductivity meter. The student made standards of NaCl solutions and recorded the following data:

% Salinity Conductivity (ms)
0.10 1.83
0.20 3.62
0.30 5.49
0.40 7.09
0.50 8.76

The conductance of a 10 mL sample of unknown was found to be 5.82 ms.

Required:
a. Prepare a standard curve using the data above.
b. Determine the concentration of the unknown salt solution using the standard curve.

Answer 1

a. is an excel document. i uploaded as an attachment

b. concentration = 0.327

Step-by-step explanation:

in the graph i uploaded for answer a, the x variable is conductivity, while the y variable is % salinity.

the calculated regression line was calculated using excel =

y = 0.057655X - 0.00891

for answer part b,

we take x = 5.82

when we put this into the y formular

y = 0.057655(5.82) - 0.00891

y = 0.3355521 - 0.00891

y = 0.3266421

this is ≈ 0.327

in conclusion, using the standard curve, the concentration of unknown salt is 0.327. the % salinity = 0.327