Answer:
±0.005 g
Explanation:
The uncertainty depends on whether the measurement was obtained manually or digitally.
1. Manual
The minimum uncertainty is ±0.01 g.
It may be greater, depending on random or personal errors
2. Digital
Most measurements of mass are now made on digital scales.
A digital device must always round off the measurement it displays.
For example, if the display reads 20.00, the measurement must be between 20.005 and 19.995 (±0.005).
If the measured value were 20.006, the display would round up to 20.01.
If the measured value were 19.994, the display would round down to 19.99.
The uncertainty is ±0.005 g.
The scale shown below would display a mass of 20.00 g
Answer:
Explanation:
A = Absorbance of solution
E = Molar absorptivity
l = Length of cuvette = 1 cm
c = Concentration of solution
Beer's law is given by
The equation of a straight line is given by
Comparing the above equations we get
Value on axis = A = Absorbance of solution = 0.23
= Slope of line = El = Molar absorptivity multiplied with length =
= Value of x axis = c = Concentration of solution
So we get
The molar concentration of the sample is