Quiz — correction exercice 1 pH2.pdf

Question 1 sur 10 20:00

[{"id":83575,"question":"Quel est le pH d'une solution dont la concentration en ions H3O+ est de 10^-3 mol\/L ?","option_a":"pH = 3","option_b":"pH = -3","option_c":"pH = 11","option_d":"pH = 14","option_e":"","option_f":"","bonne_reponse":"a","explication":"Le pH se calcule avec la formule pH = -log[H3O+]. Ici, pH = -log(10^-3) = 3.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"pH = 3\", \"b\": \"pH = -3\", \"c\": \"pH = 11\", \"d\": \"pH = 14\"}}","_debug_options_count":4},{"id":83576,"question":"Une solution de pH = 8 est-elle acide, basique ou neutre ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"Une solution de pH = 8 est basique car son pH est supérieur à 7.","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":83577,"question":"Quel indicateur coloré devient bleu en milieu basique ?","option_a":"Phénolphtaléine","option_b":"Bleu de bromophénol","option_c":"Hélianthine","option_d":"Bleu de thymol","option_e":"","option_f":"","bonne_reponse":"a","explication":"La phénolphtaléine est incolore en milieu acide et devient rose\/rouge en milieu basique.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Phénolphtaléine\", \"b\": \"Bleu de bromophénol\", \"c\": \"Hélianthi","_debug_options_count":4},{"id":83578,"question":"Si une solution a un pH = 2, quelle est sa concentration en ions H3O+ ?","option_a":"10^-2 mol\/L","option_b":"10^-12 mol\/L","option_c":"10^2 mol\/L","option_d":"10^-7 mol\/L","option_e":"","option_f":"","bonne_reponse":"a","explication":"pH = -log[H3O+] ⇒ [H3O+] = 10^-pH = 10^-2 mol\/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\": \"10^-2 mol\/L\", \"b\": \"10^-12 mol\/L\", \"c\": \"10^2 mol\/L\", \"d\": \"10^-7","_debug_options_count":4},{"id":83579,"question":"Le pH d'une solution peut-il être négatif ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Oui, si la concentration en H3O+ est supérieure à 1 mol\/L, le pH peut être négatif.","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":83580,"question":"Quelle est la couleur de la solution si on ajoute de la phénolphtaléine dans une solution de pH = 9 ?","option_a":"Incolore","option_b":"Rose","option_c":"Bleu","option_d":"Jaune","option_e":"","option_f":"","bonne_reponse":"b","explication":"La phénolphtaléine devient rose en milieu basique (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\": \"Incolore\", \"b\": \"Rose\", \"c\": \"Bleu\", \"d\": \"Jaune\"}}","_debug_options_count":4},{"id":83581,"question":"Le pH d'une solution neutre est toujours égal à 7.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"À 25°C, le pH d'une solution neutre est égal à 7. Cette valeur peut varier avec la température.","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":83582,"question":"Quelle formule permet de calculer la concentration en ions OH- à partir du pH ?","option_a":"[OH-] = 10^(pH-14)","option_b":"[OH-] = 10^pH","option_c":"[OH-] = 10^(-pH)","option_d":"[OH-] = pH","option_e":"","option_f":"","bonne_reponse":"a","explication":"On utilise la relation [H3O+][OH-] = 10^-14 ⇒ [OH-] = 10^(pH-14).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"[OH-] = 10^(pH-14)\", \"b\": \"[OH-] = 10^pH\", \"c\": \"[OH-] = 10^(-pH)","_debug_options_count":4},{"id":83583,"question":"Une solution de pH = 5 est-elle plus acide qu'une solution de pH = 3 ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"Plus le pH est bas, plus la solution est acide. pH = 3 est plus acide que pH = 5.","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":83584,"question":"Quel est le pH d'une solution de soude (NaOH) à 0,01 mol\/L ?","option_a":"pH = 2","option_b":"pH = 12","option_c":"pH = 7","option_d":"pH = 10","option_e":"","option_f":"","bonne_reponse":"b","explication":"NaOH est une base forte : [OH-] = 0,01 mol\/L ⇒ pOH = 2 ⇒ pH = 14 - pOH = 12.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"pH = 2\", \"b\": \"pH = 12\", \"c\": \"pH = 7\", \"d\": \"pH = 10\"}}","_debug_options_count":4}]