Question

Post-lab: What is the effect of each of the following on the rate of dissolving a solid in a liquid?" 1. a. Heating the solution b. Stirring the solution c. Grinding the solute (increases/decreases) (increases/decreases) (increases/decreases) 2. A 25.00mlL KCI solution with a mass of 27.913g was heated and the remaining residue has amass of 0.613g. Find the mass percent and molarity of KCI in the solution. Mass%: Molarity (M): 3. What is the molarity of a 10.0 % by mass glucose (C H1206) solution if the density of the solution is 1.04g/mL? Molarity (M):

Answer 1

1)a) heating the solution = increases

b) stirring the solution = increases

c) Grinding the solute = increases

2)KCl will be residue ,.mass of KCl =0.613g

% mass = 0.613×100/27.913

=> 2.2 %

Molarity =0.613/74.5×0.025 => 0.329 M

3) if total mass is 100 g then mass of glucose = 10 g

Moles of Glucose = 10/180 => 0.056 mol

Volume = mass/d

= 100/1.04 => 96.2 mL = 0.0962 mL

Molarity = 0.056/0.0962

=> 0.578 M