{"id":776,"date":"2020-05-05T10:57:04","date_gmt":"2020-05-05T08:57:04","guid":{"rendered":"http:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/?p=776"},"modified":"2022-02-07T16:42:21","modified_gmt":"2022-02-07T15:42:21","slug":"calculs-courants-au-labo","status":"publish","type":"post","link":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/2020\/05\/05\/calculs-courants-au-labo\/","title":{"rendered":"Calculs courants au labo"},"content":{"rendered":"

Calculs courants au laboratoire<\/b><\/u><\/span><\/h1>\n

 <\/p>\n

Je vous propose de regrouper dans cet article les diff\u00e9rents calculs que l’on utilise tous les jours au laboratoire pour pr\u00e9parer des solutions.<\/span><\/p>\n

On notera :<\/span><\/p>\n

n= quantit\u00e9 de mati\u00e8re (mol)<\/span><\/p>\n

C= concentration molaire (mol.L-1<\/sup>)<\/span><\/p>\n

V= volume (L) et Vm\u00a0<\/sub>= volume molaire (L.mol-1<\/sup>)<\/span><\/p>\n

m= masse (g)<\/span><\/p>\n

M=masse molaire (g.mol-1<\/sup>)<\/span><\/p>\n

Cm<\/sub> =concentration massique (g.L-1<\/sup>)<\/span><\/p>\n

 <\/p>\n

Les formules:\u00a0<\/span><\/h3>\n

 <\/p>\n

n=m\/M<\/span><\/strong><\/span><\/h4>\n

 <\/p>\n

n=C x V donc C=n\/V<\/span><\/strong><\/p>\n

 <\/p>\n

masse \u00e0 pr\u00e9lever lors d\u2019une pr\u00e9paration \u00e0 partir d\u2019une poudre\u00a0: <\/span><\/span><\/p>\n

m= M x C x V<\/span><\/strong><\/span><\/p>\n

 <\/p>\n

Cm<\/sub>=m\/V et m=MCV donc Cm<\/sub> =MC<\/span><\/strong><\/span><\/p>\n

 <\/p>\n

volume \u00e0 pr\u00e9lever lors d\u2019une dilution\u00a0: <\/span><\/span><\/p>\n

Vm\u00e8re<\/sub>=Cfille<\/sub> x Vfille<\/sub> \/ Cm\u00e8re<\/sub> <\/span><\/strong><\/p>\n

 <\/p>\n

facteur de dilution <\/span><\/span><\/p>\n

k=Cm\u00e8re<\/sub>\/Cfille<\/sub>=Vfille<\/sub>\/Vm\u00e8re<\/sub><\/span><\/strong><\/p>\n

 <\/p>\n

calcul concentration solution m\u00e8re commerciale\u00a0:<\/span><\/span><\/p>\n

C0<\/sub>=\u00a0% x d x 1000\/M<\/span><\/strong><\/span><\/p>\n

ex n\u00b01: solution HCl (M= 36,5g.mol-1<\/sup>) \u00e0 37\u00a0% et densit\u00e9 d=1,16\u00a0: C0<\/sub>=0,37 x 1,16 x 1000 \/36,5=11,76 mol.L-1<\/sup><\/span><\/span><\/p>\n

 <\/p>\n

ex n\u00b02: une solution d’acide sulfurique:\u00a0 d=1,83 \u00e0 98% pour M=98g.mol-1<\/sup>, C0<\/sub>=1,83x1000x0,98\/98=18,3 mol.L-1<\/sup><\/p>\n

 <\/p>\n

ex n\u00b03: acide \u00e9thano\u00efque: d=1,049 \u00e0 99% pour M=60,05g\/mol donc Co=1,049x1000x0,99\/60.05=17,29mol\/L<\/p>\n

 <\/p>\n

Lorsque l’on parle d’un gaz parfait, on peut utiliser la formule<\/span><\/p>\n

n= V \/ Vm<\/sub><\/span><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

Calculs courants au laboratoire   Je vous propose de regrouper dans cet article les diff\u00e9rents calculs que l’on utilise tous les jours au laboratoire pour pr\u00e9parer des solutions. On notera : n= quantit\u00e9 de mati\u00e8re (mol) C= concentration molaire (mol.L-1) V= volume (L) et Vm\u00a0= volume molaire (L.mol-1) m= masse (g) M=masse molaire (g.mol-1) Cm … Continuer la lecture de Calculs courants au labo<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-776","post","type-post","status-publish","format-standard","hentry","category-tp-et-calculs"],"_links":{"self":[{"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/posts\/776","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/comments?post=776"}],"version-history":[{"count":6,"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/posts\/776\/revisions"}],"predecessor-version":[{"id":3471,"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/posts\/776\/revisions\/3471"}],"wp:attachment":[{"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/media?parent=776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/categories?post=776"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/toulouse-sgencfdt.fr\/WORDPRESS_ITRF\/wp-json\/wp\/v2\/tags?post=776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}