A student in a chemistry laboratory has access to two acid solutions. The first one is 20% acid and the second solution is 45% acid.(The percentages are by volume). How many millilitres of each solution should the student mix together to obtain 100ml of a 30% acid solution?

For the preparation of the 30% 100 ml acid solution, 40 ml 45% solution has been mixed with 60 ml 20% acid solution.

To prepare the solution with the concentrated solution:

MV = M1V1 + M2V2

The M has been the concentration of the resulted solution, and V has been the volume of the resulting solution.

M1 and M2 and V1 and V2 have been the concentration and volume of the given solution.

0.30 × 100 ml = 0.20 × x + 0.45 × (100 - x)

30 = 0.20x + 45 - 0.45x

0.45x - 0.20x = 45 - 30

0.25x = 15

x = 60 ml

The volume of 20% solution has been x = 60 ml

The volume of 45% solution has been 100 - x = 40 ml.

For the preparation of the 30% 100 ml acid solution, 40ml 45% solution has been mixed with 60ml 20% acid solution.

For more information about the acid preparation, refer to the link:

link

Volume of each solution : 60 ml 20% and 40 ml 45%

Given

20% and 45% acid

100 ml of 30% acid

Required

Volume of each solution

Solution

Molarity from 2 solutions :

Vm Mm = V₁. M₁ + V₂. M₂  

m = mixed solution

V = volume

M = molarity

V₁ = x ml

V₂ = (100 - x) ml

Input the value :

100 . 0.3 = x . 0.2 + (100-x) . 0.45

30 = 0.2x+45-0.45x

0.25x=15

x= 60 ml

V₁ = 60 ml

V₂ = 100 - 60 = 40 ml

i believe it is c.) 1575 j.

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).