Hey there!
MgCl₂
Find molar mass of magnesium chloride.
Mg: 1 x 24.305
Cl: 2 x 35.453
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95.211 grams
One mole of magnesium chloride has a mass of 95.211 grams.
We have 2.40 moles.
2.40 x 95.211 = 228.5
To 3 sig figs this is 229.
The mass of 2.40 moles of magnesium chloride is 229 grams.
Hope this helps!
The atomic mass of Cs is 132.9. So the mole number of 675 g cesium is 675/132.9 = 5.08 mole. Then the answer should be 5.08 mole.
Spectrophotometric cell or a cuvette is made of quartz for UV spectrophotometers. These cuvettes are used as sample holders for the spectrophotometric determination of the analytes. The material that makes up the cuvette and the condition of the cuvette is to be taken care of in order to avoid erroneous absorbance readings. The sample holder or the cuvette must be removed from the spectrophotometer in between two successive readings. This is to ensure that the light sensing detector of the instrument is not affected.