20mL of the pure formic acid (HCOOH) liquid is mixed with 40mL of pure water to prepare a solution. If the density of pure formic acid liquid, pure water and the solution are 1.15g/mL,1g/mL and 98g/mL, then:
A
The volume expansion upon mixing the two pure liquids is 3.33%
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
The volume contraction upon mixing the two pure liquids is 6.66%
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
Mole fraction of formic acid in the solution is 950
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
%w/v of the resulting solution will be 3813%
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is B The volume contraction upon mixing the two pure liquids is 6.66% (Vmix)actual=mmixdmix=mHCOOH+mH2Odmix =1.15×20+1×409/8=56mL (Vmix)expected=20+40=60mL ∴ % contraction in volume =60−5660×100=6.66%XHCOOH=1.15×20461.15×2046+4018=949 ⇒%w/v=wtHCOOHVsol×100=2356×100=41.07%