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:
9.0 moles of CaO
Explanation:
We have the reaction equation as follows;
Fe2O3 + Ca3(PO4)2 -------> 2FePO4 + 3CaO
Now we know from the equation that;
1 mole of iron III oxide yields 3 moles of CaO
Therefore;
3 moles of iron III oxide yields 3 * 3/1
= 9.0 moles of CaO
Answer:
watching a firefly is much different than watching a fire because watching a fire can make you hot and watching a firefly can make you happy
The molecular formula of HgCl (m = 5 472.1 g/mol) is Hg2Cl4.
The molecular formula is an expression that defines the number of atoms of each element in one molecule of a compound. It shows the actual number of each atom in a molecule.
<h3>Molecular formula: What is it?</h3>
A chemical formula is a way to communicate information in chemistry about the proportions of atoms that make up a specific chemical compound or molecule. Chemical element symbols, numbers, and occasionally other symbols like parentheses, dashes, brackets, commas, and plus and minus signs are used to represent the chemical elements.
A molecule's molecular formula reveals which atoms and how many of each kind are included within it. No subscript is used if there is just one atom of a certain kind. A subscript is added to the symbol for an atom if it contains two or more of a certain type of atom.
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A graph depicting a direct relation is a straight line and usually has positive slope. An inverse relation is a curve, typically concave up with negative slope.
