The closeness of a measurement to its true value is a measure of its accuracy. This term is the degree of which a certain measurement conforms to the correct value or the standard value. It is not the same with the term precision. Precision, on the other hand, is a measure used to characterize the closeness of the data measured.
When Water freezes or begin to freeze, it molecules start to slow down enough that their attraction arrange into one shape till they melt again.
Answer:
see explanation below
Explanation:
Question is incomplete, so in picture 1, you have a sample of this question with the missing data.
Now, in general terms, the absorbance of a substance can be calculated using the beer's law which is the following:
A = εlc
Where:
ε: molar absortivity
l: distance of the light in solution
c: concentration of solution
However, in this case, we have a plot line and a equation for this plot, so all we have to do is replace the given data into the equation and solve for x, which is the concentration.
the equation according to the plot is:
A = 15200c - 0.018
So solving for C for an absorbance of 0.25 is:
0.25 = 15200c - 0.018
0.25 + 0.018 = 15200c
0.268 = 15200c
c = 0.268/15200
c = 1.76x10⁻⁵ M
Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of = 183.511 g/mole
- First we have to calculate the moles of Cu.
The moles of Cu = 4.7209 moles
From the given chemical formula, we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of = 4.4209 moles
- Now we have to calculate the mass of .
Mass of = Moles of × Molar mass of = 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of = 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.