<p>could you help me with this:</p>
<p>[1] An aqueous solution of HCl contains 28% HCL by weight and has a density of 1.2g/mL. Find the molarity of the solution.</p>
<p>[2] Determine th Oxidation State of the bolded element in...</p>
<p>a:: ICl</p>
<p>b:: Ca(ClO2)2</p>
<p>thanx</p>
<p>Well I would hardly claim to be a chemistry whiz but I think I can help. For 1, I'm pretty sure you just play around with the numbers, using dimensional analysis and the molarity formula (M=m/L) to get the answer (I took chemistry last year so I can't recall the exact details). For 2, the net charge is 0. Cl typically has a -1 charge so I must have a +1 to balance it. For the second one, the net charge is again 0. Ca has a +2 charge. So what is inside has to balance it out. O typically has a -2.</p>
<p>please help...</p>
<p>[1] An aqueous solution of HCl contains 28% HCL by weight and has a density of 1.2g/mL. Find the molarity of the solution.
1 mL <---> 1.2 g of solution
Since HCl = 28% by weight,
1 mL <---> 0.28*1.2 g of HCl = 0.336g</p>
<p>Molar mass (relative atomic mass) of HCl = 1 + 35.5 = 36.5 g/mol
Moles of HCl in 1 mL of solution = (0.336g)/(36.5g/mol) = 9.21<em>10^-3 mol
Molarity of solution = Moles/Volume = (9.21</em>10^-3mol)/(10^-3L)= 9.21 M </p>
<p>[2] Determine the Oxidation State of the bolded element in...
a:: ICl
-Cl is more electronegative. Hence it'd have a negative Oxidation State of -1. Since the overall charge is 0, the Oxidation State of I must be +1 to balance it out.
b:: Ca(ClO2)2
-Charge of ClO2 anion = -1 (since two of ClO2- balance Ca2+)
-Oxidation state of O is -2 (for all cases involving oxygen except peroxides)
x - 4 = -1, x = +3
-Oxidation State of Cl is +3</p>
<p>thanx...you are so awesome!</p>
<p>but 9.21 seems kinda high for a Molarity value, can anyone else confimr fiona's answers...thanx</p>
<p>The method and results look right. While 9.2 M HCl is very acidic, it happens to be very concentrated.</p>
<p>Why would "9.21" be high for a molarity? The only limit to molarity is solubility.</p>
<p>I think 9.21 is high because HCl is already a very acidic solution. I'm not sure if you know the acid/base equations but it actually yields a pH below 0.</p>
<p>Slightly related and slightly not... I know all about how acidic 9M is! We worked with 18M sulfuric acid in gen chem lab last year! Now that is scary stuff; got a drop on a paper towel and it just turned it jet black.</p>