find the molarity of a 7.85% aqueous ammonia solution that has a density of 0.96
ID: 479239 • Letter: F
Question
find the molarity of a 7.85% aqueous ammonia solution that has a density of 0.965g/mL ator to moles: 1 mol HCI 1.02 mol HC1 mol HCI 37.2 HCT x Using the density of the solution to convert to a volume of solution 1 mL 96.7 mL solution 100 solution. x 1.034 To determine molarity, we need to have the volume in liters, not milliliters 1 L 0.0967 L solution 96,7 prm solution X 1000 Combining the number of moles and the volume of solution gives the mo ty of the 1.02 mol HC1 M 0.0967 L solution 10.5 M HCI Understanding Find the molarity of a 7.85% aqueous ammonia solution that has a density of 0.965 g/ml Answer 4.77 M Why is molality useful? Unlike molarity, the molality of a solution does not change with temperature. Typically, the volume of a solution expands as the temperature is increased, so the molarity decreases (because the volume of the solution is in the denominator of the definition of molarity). However, the mass of the solvent stays the same even if the volume expands or contracts with temperature. Thus, molality temperature-independent concentration unit. (Mass percent and mole fraction are tem toichiometric amounts directly from the volume of the solution, which is usually easy o measure experimentally. The choice of which concentration unit to use xactly how you intend to apply the concentration of the solution. BJECTIVES REVIEW,Explanation / Answer
Q.
find the molarity of a 7.85% aqueous ammonia solution that has a density of 0.965g/mL
M = mol/V
Assume a basis of
V = 1 liter solution or 1000 mL
so
mass of solution = D*V = 0.965*1000 = 965 g of solution
from that,
7.85% is NH3 so
7.85/100*965 = 75.7525 g of NH3 are present
MW of NH3 = 17 g/mol
so
mol = mass/MW = 75.7525/17 = 4.4560 mol
so...
M = mol/V = 4.4560/1 = 4.4560 M
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.