Question

3.97 Six different aqueous solutions (with solvent molecules omitted for clarity) are represented in the beakers below, and their total volumes are noted. 50. mL 50. mL 50. mL 50. mL 25 mL 25 mL E (a) Which solution has the highest molarity? (b) Which solutions have the same molarity? (c) If you mix solutions A and C, does the resulting solution have a higher, a lower, or the same molarity as solution B? (d) After 50 mL of water is added to solution D, is its molarity higher, lower, or the same as the molarity of solution F after 75 mL is added to it? (e) How much solvent must be evaporated from solution E for it to have the same molarity as solution A?

Answer 1

3.97 Molenity is defined as the number of indles of solute dissolved in 14 of solution M = nood moles x 1000. Voleme of solution CmL) If we consider the I Circle represent a unit volume. Then, number of moles of particles Can define the molarity Solution (B) has the highest molarity as in a unit volume it has maximum no. of moles of particles on solute. Solution (C) and solution CD) has same molanla as no. of partides u unit volume is name and total Volume if solution is also same (b) 20 ank som Me= 4 x oom - 80m. Considering 4 moles in } the whole solchon Moa 4. xloom a som. A has higher molanty (B) has lower melang on mixing them, we get to average molants and this molants will be higher than solution 'B'. (d) ® on adding 50 mL of the, the molarity would decreases o an adding 75 mLd tho, its molanty would also decreases Both have similar malang, since ditution occur more in care f therefore Mo) Mr (Dmolanty would be higher than f) VTT

(e) E has Molanly 2 mil xt som. Jul 250ml A = 8 mol x 8 = 160m. 160 M, we need to evaporate the To Make Solution E as as a lom I mot x lao = 160 mol l non Volume cmis & Volene - 8x love = 12.5 mL. woorlogtoon Hence, to make the molanty of 6 and (A) equal, we need to evalporate it to half! Evaporate solution E from 25 to 12.5mL.