The purpose of using distilled water in the cuvette of the spectrophotometer is to calibrate the instrument. It is generally considered that distilled water shows zero absorbance and 100 % transmittance. So, to zero out the absorbance of compounds other than the analyte being determined, distilled water is used as a blank.
If the unknown being determined is prepared using ethanol as the base solution, the blank used must be ethanol. This is because absorbance if any from the solvent, ethanol must be zeroed out as when the measurement of the actual unknown is being made, the absorbance of the solvent does not interfere.
Answer:
Actual yield: 86.5 grams.
Explanation:
How many moles of formula units in 95 grams of calcium carbonate ?
Refer to a modern periodic table for relative atomic mass data:
- Ca: 40.078;
- C: 12.011;
- O: 15.999.
Formula mass of :
.
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How many moles of will be produced?
The coefficient in front of in the chemical equation is the same as that in front of . That is:
.
.
What's the theoretical yield of calcium chloride? In other words, what's the mass of of ?
Again, refer to a periodic table for relative atomic data:
.
.
What's the actual yield of calcium chloride?
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C.Pennsylvania Titusville is in the state of Pennsylvania
Lewis diagram:
well first you have to know the Valence electrons the elements which will on top of the periodic table.
for examples:
H2O
it will be O-H-O and the dots will on top. oxygen have 6 valence electrons so that mean it need 6 dots. also for H it will have 7 V-electrons.