how do i figure out concentration? or What is the concentration of 28% isopropyl?

Answer 1

assume 28% isoproply alcohol,

we'll use the density as 0.7854g/ml.
this means for every 1L, there are
(0.28)(785.4g) = 219.66 g

Formula isopropyl alcohol is CH3CHOHCH3
molar mass = 60g/mol

# moles = 219.66g/60g/mol = 3.66 mol

Concentration, expressed in moles/liter or molarity:
molarity = #moles solute/liters soln
[alcohol] = 3.66mol/1L = 3.66M

Now if your want the concentration by volume, it would be 28% , or 28ml of alcohol per 100ml mixture.

Answer 2

First we need to know the correct formula for the chemical. Is it isopropyl acohol (C3H8O), isopropyl chloride (C3H8Cl) or some other isopropyl alkane?

Assuming it is isopropyl alcohol; find the molar weight of the molecule: 60.09 g/mole

A 28% solution is 28g isopropyl acohol in 100g final solution weight. Assume your solvent is water and the densitiy of the final solution is 1.00g/mL.
28% = 28g/100g = (28g/60.09 g/mol) / 0.1L = 4.66 mol/L
or 4.6M. Then a 28% solution of isopropyl alcohol in water is 4.6M.

Answer 3

I think that depends on what units you want the concentration in. 28 % is the concentration if you are looking for a percentage. It is also 280,000 ppm (ppm = mg/l). There are other units of concentration.