Answer:
1.8g
Explanation:
Initial volume = 43.5ml
Final volume = 49.4ml
Mass = 10.88g
Density = ?
Volume = Final volume - initial volume
= 49.4 - 43.5
= 5.9ml
Density = Mass/volume
Density = 10.88/5.9
= 1.8g/ml
In dilute solutions, the unit osmolarity is being used. It usually has units milliosmols per liter of solution or mOsmol/L. An osmole defines the number of moles of the solute that would have an effect on the osmotic pressure of the solution. Osmolarity is calculated by the product of the molarity and the number of particles in the solution which is 2 for potassium chloride. We calculate as follows:
Osmolarity = molarity (# of particles)250 mosmol/L ( 1 osmol / 1000 osmol) = x moles / .100 L (2)
x moles = 0.0125 mol KCl
mass KCl = 0.0125 mol KCl ( 39 + 35.5 g/mol) = 0.93125 g KCl
If I made no mistake in calculation, the given answer must be correct...(tried my best)
elements : carbon hydrogen oxygen Fluorine
composition [C] 24 3 16 57
M r 12 1 16 19
(divide C by Mr) 2 3 1 3
(Divide by smallest value) 2 3 1 3
(smallest value = 1...so all value remained constant)
Empirical formula : C2H3OF3
if molar mas = 100 g per mole, then
first step calculate Mr. of empirical formula: [= 100]
Them molecular formula = empirical formula