Un 8. Quantité de matière et volume d'un liquide
ins
de
Un chimiste synthétise un ester à odeur de banane
utilisé pour parfumer certains sirops ou confiseries. Il
introduit dans un ballon, en prenant les précautions
nécessaires, les quantités de matière n, = 0,50 mol
d'alcool isoamylique (CH20) et n2 =
d'acide acétique (C2H4O2). Quels volumes V, et V2
d'alcool et d'acide doit-il prélever ?
0,10 mol
Données :
Masses volumiques de l'alcool isoamylique et de l'eau :
Py = 0,810 g. mL et peau = 1,0 g. mL.
e
Densité de l'acide acétique : d2 = 1,05.
M(C) = 12 g. mol; M(O) = 16; M(H) = 19.mol

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.