CHEMl 103l /l CHEM103l Modulel 6:l
(Latestl 2025/l 2026l Update)l Generall Chemistryl Il W/l Labl |l Questionsl &l Answers|l Gradel A|l 100%l Correctl (Verifiedl Solutions)-l Portagel Learning
Q:l Showl thel calculationl ofl thel massl ofl NaNO3l neededl tol makel 450l mll ofl al 0.356l Ml solution.
Answer:
Molarityl =l (moles)l /l (mlsolution/l 1000)
0.356l =l (moles)l /l (450l /l 1000)
Molesl =l 0.356l xl 0.450l =l 0.1602
Molesl =l (gsolutel /l MW)
0.1602l =l (gsolutel /l 85.0)
gsolutel =l 0.1602l xl 85.0l =l 13.6l g
Q:l Showl thel calculationl ofl thel volumel ofl 0.987l Ml solutionl whichl canl bel preparedl usingl 24.6l gramsl ofl NaNO3.
Answer:
molessolutel =l gsolutel /l MW 1 / 2
molessolutel =l 24.6l gl /l 85.0l =l 0.2894l mol
Molarityl =l molesl /l (mLl /1000)
0.987l =l 0.2894l /l (mLl /l 1000)
mLl /l 1000l =l 0.2894l /l 0.987l =l 0.2932
mLl =l 0.2932l xl 1000l =l 293l mL
Q:l Showl thel calculationl ofl thel freezingl pointl ofl al solutionl madel byl dissolvingl 12.6l gramsl ofl thel nonelectrolytel C2H5OHl inl 200l gramsl ofl water.l Kfl forl waterl isl 1.86,l FPl ofl purel waterl isl 0C.
Answer:
molalityl =l (gsolutel /l MW)l /l (gsolventl /l 1000)
molalityl =l (12.6l /l 46.07)l /l (200l /l 1000)l =l 1.37l m
∆tfl =l Kfl xl ml =l 1.86l xl 1.37l =l 2.55l C
FPsolutionl =l FPsolventl -l ∆tfl =l 0l Cl -l 2.55l =l -l 2.55l C
Q:l Showl thel calculationl ofl thel freezingl pointl ofl al solutionl madel byl dissolvingl 12.6l gramsl ofl thel electrolytel NaNO3l inl 200l gramsl ofl water.l Kfl forl waterl isl 1.86l andl thel FPl ofl purel waterl isl 0l C.
Answer:
molalityl =l (gsolutel /l MW)l /l (gsolventl /l 1000)
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