Quiz — 4. BA zout 0...pdf

Question 1 sur 10 20:00

[{"id":34510,"question":"Quelle est l'unité de la molarité (concentration molaire) ?","option_a":"mol\/L","option_b":"g\/L","option_c":"mol\/mL","option_d":"g\/mol","option_e":"","option_f":"","bonne_reponse":"a","explication":"La molarité s'exprime en moles par litre (mol\/L), car elle représente le nombre de moles de soluté par litre de solution.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"mol\/L\", \"b\": \"g\/L\", \"c\": \"mol\/mL\", \"d\": \"g\/mol\"}}","_debug_options_count":4},{"id":34511,"question":"Pour préparer 500 mL d'une solution de NaCl à 0,1 mol\/L, quelle masse de NaCl faut-il peser ? (Masse molaire de NaCl = 58,5 g\/mol)","option_a":"2,925 g","option_b":"5,85 g","option_c":"11,7 g","option_d":"29,25 g","option_e":"","option_f":"","bonne_reponse":"a","explication":"Calcul : masse = 0,1 mol\/L × 0,5 L × 58,5 g\/mol = 2,925 g. Il faut donc peser 2,925 g de NaCl.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"2,925 g\", \"b\": \"5,85 g\", \"c\": \"11,7 g\", \"d\": \"29,25 g\"}}","_debug_options_count":4},{"id":34512,"question":"Lors d'une dilution, la quantité de matière (nombre de moles) du soluté reste inchangée.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Lors d'une dilution, seule la quantité de solvant augmente, donc le nombre de moles de soluté reste constant.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":34513,"question":"Quelle est la concentration molaire d'une solution obtenue en mélangeant 200 mL d'une solution à 0,5 mol\/L et 300 mL d'eau pure ?","option_a":"0,2 mol\/L","option_b":"0,3 mol\/L","option_c":"0,4 mol\/L","option_d":"0,5 mol\/L","option_e":"","option_f":"","bonne_reponse":"b","explication":"Le nombre total de moles est 0,5 mol\/L × 0,2 L = 0,1 mol. Le volume total est 0,5 L, donc la concentration est 0,1 mol \/ 0,5 L = 0,2 mol\/L.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"0,2 mol\/L\", \"b\": \"0,3 mol\/L\", \"c\": \"0,4 mol\/L\", \"d\": \"0,5 mol\/L\"}","_debug_options_count":4},{"id":34514,"question":"La formule C1 × V1 = C2 × V2 s'applique uniquement aux mélanges de solutions de même soluté.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Cette formule s'applique uniquement lorsque le nombre de moles de soluté reste constant, comme lors d'une dilution ou d'un mélange de solutions du même soluté.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":34515,"question":"Quel volume d'eau faut-il ajouter à 100 mL d'une solution à 2 mol\/L pour obtenir une solution à 0,5 mol\/L ?","option_a":"200 mL","option_b":"300 mL","option_c":"400 mL","option_d":"500 mL","option_e":"","option_f":"","bonne_reponse":"c","explication":"Utilisez C1 × V1 = C2 × V2 : 2 × 0,1 = 0,5 × V2 → V2 = 0,4 L = 400 mL. Il faut donc ajouter 300 mL d'eau (400 mL - 100 mL).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"200 mL\", \"b\": \"300 mL\", \"c\": \"400 mL\", \"d\": \"500 mL\"}}","_debug_options_count":4},{"id":34516,"question":"La concentration massique s'exprime en grammes par litre (g\/L).","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"La concentration massique est bien définie comme la masse de soluté (en grammes) par litre de solution (g\/L).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":34517,"question":"Quelle est la concentration molaire d'une solution contenant 11,7 g de NaCl dissous dans 250 mL d'eau ? (Masse molaire de NaCl = 58,5 g\/mol)","option_a":"0,2 mol\/L","option_b":"0,4 mol\/L","option_c":"0,8 mol\/L","option_d":"1,0 mol\/L","option_e":"","option_f":"","bonne_reponse":"b","explication":"Nombre de moles = 11,7 g \/ 58,5 g\/mol = 0,2 mol. Volume = 0,25 L, donc concentration = 0,2 mol \/ 0,25 L = 0,8 mol\/L.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"0,2 mol\/L\", \"b\": \"0,4 mol\/L\", \"c\": \"0,8 mol\/L\", \"d\": \"1,0 mol\/L\"}","_debug_options_count":4},{"id":34518,"question":"Lors d'un mélange de deux solutions de solutés différents, la concentration finale dépend uniquement du volume total.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"La concentration finale dépend des concentrations et volumes des solutions initiales, ainsi que des masses molaires des solutés.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":34519,"question":"Quelle masse de glucose (C6H12O6) faut-il dissoudre dans 250 mL d'eau pour obtenir une solution à 0,4 mol\/L ? (Masse molaire du glucose = 180 g\/mol)","option_a":"18 g","option_b":"36 g","option_c":"72 g","option_d":"180 g","option_e":"","option_f":"","bonne_reponse":"a","explication":"Nombre de moles = 0,4 mol\/L × 0,25 L = 0,1 mol. Masse = 0,1 mol × 180 g\/mol = 18 g.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"18 g\", \"b\": \"36 g\", \"c\": \"72 g\", \"d\": \"180 g\"}}","_debug_options_count":4}]