Sc Fc a Starting concentration minus the final concentrati

Sc – Fc = a Starting concentration minus the final concentration equals H2O variable (a)

Fv / Sc = b Final volume divided by starting concentration equals multiplier (b)

b x Fc = c Multiplier times Final concentration equals volume (c) of Starting concentration

b x a = d Multiplier x H2O variable equals volume (d) of water added

show your work.

Calculate how much EtOH is needed to produce the following;

600ml of 17% EtOH using 35% EtOH_________________

Solution

Starting concenntration is: 35% (S_C)

Final concentration is 17% (F_C)

Final volume = 600 ml (FV)

Following are provided in the question:

Variable \"a\" = S_C- F_C, which is equal to (35-17) % = 18%

Variable \"b\" = F_V/S_{C ,} which is equal to (600/35) = 17.14

Variable \"c\" = b X F_C , which equals, 17.14/35 = 0.489

Variable d = bXa = 17.14 X 18 = 308.52

However the concentration formula , C1V1=C2V2 , can be used to make 17 % EtOH from 35% EtOH

here, C1= 35%

C2= 17%

V2 = 600 ml

so given all the variables V1 can be calculated

35 X V1 = 17 X 600

V1 = 17X600/35 =291.42 ml

So taking 291.42 ml EtOH from 35 % and making up volume till 600 ml, will give 17% EtOH.