Quiz — Lycée Pilote Sfax - Réactions Acide-Base.pdf

Question 1 sur 10 20:00

[{"id":4566,"question":"Quel est le pH d'une solution de HCl à 0,01 mol\/L ?","option_a":"1","option_b":"2","option_c":"7","option_d":"12","option_e":"","option_f":"","bonne_reponse":"b","explication":"HCl est un acide fort qui se dissocie complètement. Le pH = -log[H3O+] = -log(0,01) = 2.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"1\", \"b\": \"2\", \"c\": \"7\", \"d\": \"12\"}}","_debug_options_count":4},{"id":4567,"question":"Un indicateur coloré change de couleur lorsque le pH de la solution atteint sa zone de virage.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Un indicateur coloré change de couleur dans sa zone de virage, qui correspond à une plage de pH spécifique.","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":4568,"question":"Quelle est la formule de la constante d'acidité Ka pour un acide AH ?","option_a":"Ka = [AH]\/([A-][H3O+])","option_b":"Ka = [A-][H3O+]\/[AH]","option_c":"Ka = [H3O+]\/[AH]","option_d":"Ka = [AH][A-]\/[H3O+]","option_e":"","option_f":"","bonne_reponse":"b","explication":"La constante d'acidité Ka est définie par Ka = [A-][H3O+]\/[AH], où [A-] est la concentration de la base conjuguée.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Ka = [AH]\/([A-][H3O+])\", \"b\": \"Ka = [A-][H3O+]\/[AH]\", \"c\": \"Ka = ","_debug_options_count":4},{"id":4569,"question":"Lors d'un dosage acido-basique, le point d'équivalence correspond à :","option_a":"Un changement de couleur de l'indicateur","option_b":"L'égalité des quantités de matière d'acide et de base","option_c":"Un pH de 7","option_d":"La fin de la réaction","option_e":"","option_f":"","bonne_reponse":"b","explication":"Le point d'équivalence est atteint lorsque les quantités de matière d'acide et de base sont stœchiométriquement égales.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Un changement de couleur de l'indicateur\", \"b\": \"L'égalité des ","_debug_options_count":4},{"id":4570,"question":"Le produit ionique de l'eau Kw est égal à :","option_a":"10^-7","option_b":"10^-14 à 25°C","option_c":"1","option_d":"0","option_e":"","option_f":"","bonne_reponse":"b","explication":"À 25°C, Kw = [H3O+][OH-] = 10^-14. Cette valeur dépend de la température.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"10^-7\", \"b\": \"10^-14 à 25°C\", \"c\": \"1\", \"d\": \"0\"}}","_debug_options_count":4},{"id":4571,"question":"Une solution tampon est efficace pour maintenir un pH constant.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Une solution tampon résiste aux changements de pH lorsqu'on ajoute une petite quantité d'acide ou de base, mais elle ne maintient pas un pH strictement 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":4572,"question":"Quel est le pH d'une solution de soude (NaOH) à 0,001 mol\/L ?","option_a":"3","option_b":"11","option_c":"7","option_d":"13","option_e":"","option_f":"","bonne_reponse":"b","explication":"NaOH est une base forte qui se dissocie complètement. Le pH = 14 + log[OH-] = 14 + log(0,001) = 11.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"3\", \"b\": \"11\", \"c\": \"7\", \"d\": \"13\"}}","_debug_options_count":4},{"id":4573,"question":"La phénolphtaléine est un indicateur coloré qui vire au rose dans un milieu :","option_a":"Acide (pH \u003C 7)","option_b":"Basique (pH \u003E 8,2)","option_c":"Neutre (pH = 7)","option_d":"Toujours incolore","option_e":"","option_f":"","bonne_reponse":"b","explication":"La phénolphtaléine vire du incolore au rose dans un milieu basique, généralement pour un pH \u003E 8,2.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Acide (pH \u003C 7)\", \"b\": \"Basique (pH \u003E 8,2)\", \"c\": \"Neutre (pH = 7)","_debug_options_count":4},{"id":4574,"question":"Pour un acide faible AH de constante d'acidité Ka, le pH d'une solution de concentration C est donné par :","option_a":"pH = -log(C)","option_b":"pH = -log(Ka)","option_c":"pH = 1\/2(pKa - log(C))","option_d":"pH = -log(sqrt(Ka*C))","option_e":"","option_f":"","bonne_reponse":"d","explication":"Pour un acide faible, [H3O+] = sqrt(Ka*C), donc pH = -log(sqrt(Ka*C)) = 1\/2(pKa - log(C)).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"d\", \"options\": {\"a\": \"pH = -log(C)\", \"b\": \"pH = -log(Ka)\", \"c\": \"pH = 1\/2(pKa - log(C))","_debug_options_count":4},{"id":4575,"question":"Un dosage acido-basique permet de déterminer la concentration d'une solution inconnue.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Un dosage acido-basique permet effectivement de déterminer la concentration d'une solution inconnue en utilisant une solution titrante de concentration connue.","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}]