Answer:
1.8 moles of NaCl must be produced.
Explanation:
Based on the reaction:
HCl + NaOH → NaCl + H2O
<em>1 mol of HCl reacts with 1 mol of NaOH to produce 1mol of NaCl</em>
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To solve this question we must find, as first, the <em>limiting reactant:</em>
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1.8 moles of HCl will need 1.8 moles of NaOH for a complete reaction (Ratio of reaction 1:1). As there are 3.3 moles of NaOH,
<em>HCl is limiting reactant</em>
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When the 1.8 moles of HCl react completely,
1.8 moles of NaCl must be produced because 1 mole of HCl produce 1 mole of NaCl
I would say it is a chemical change because after a while, the nails start to rust. Now they only rust after about a week though. But rust is a chemical change.
<u>Answer:</u> Osmolarity of the sodium chloride solution is 18 Osmol/L.
<u>Explanation:</u>
Osmolarity is defined as the the concentration of the solution which is expressed as the total number of solution particles present in one liter of solvent.
We are given the molarity of the solution which is 3mol/L and to convert it into osmolarity, we will multiply the number of osmoles that are produced by the solute.
Osmole is defined as the particles that contribute to the osmotic pressure of a solution.
The solute given here is sodium chloride (NaCl). Number of osmoles can be determined by the dissociation of this solvent into ions.
The equation given by the dissociation of NaCl:

1 mole of sodium chloride produces 2 moles of ions.
So, 3 moles of sodium chloride will produce = (3 × 2) = 6 moles of ions.
Hence, osmolarity of the sodium chloride solution will be 
It would be Magnesium = 1 atom, Oxygen = 2 atoms, Hydrogen = 2 atoms. It has 5 atoms total. There is 1 magnesium and you multiply each element by the the 2 outside the parenthesis to get 2 oxygen and 2 hydrogen.