5. Différentes formules d'un alcool Un composé (A) de formule CHO, à chaîne
carbonée saturée, présente les particularités suivantes:
son atomicité est égale à 12
le pourcentage massique d'oxygene vaut 2 fois celui
d'hydrogène
sa densité de vapeur est d = 2,07,
a) Trouver la formule brute de (A).
b) Déterminer ses formules semi-développées sachant
qu'il renferme le groupe hydroxyde OH,
caractéristique de la fonction alcool
.
c) Déduire les formules topologiques de (S).
M(O) = 12 g. mol; M(O) = 16 g. mol​

the answer is 1260

you spend 7 hours in school for 1 school day with 5 school days in 1 school week with 36 school weeks in a school year.

7*5*36= 1260 it's all about multiplying

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol