Quiz — Chimie.ép.cont.pdf

Question 1 sur 10 20:00

[{"id":24194,"question":"Quel est le pH d'une solution de HCl à 0,01 mol\/L ?","option_a":"1","option_b":"2","option_c":"3","option_d":"7","option_e":"","option_f":"","bonne_reponse":"b","explication":"Le pH d'une solution d'acide fort se calcule par pH = -log[H₃O⁺]. Ici, [H₃O⁺] = 0,01 mol\/L, donc pH = -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\": \"3\", \"d\": \"7\"}}","_debug_options_count":4},{"id":24195,"question":"Une réaction chimique est à l'équilibre lorsque les concentrations des réactifs et produits sont égales.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"Non, l'équilibre chimique signifie que les vitesses des réactions directe et inverse sont égales, pas nécessairement les concentrations.","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":24196,"question":"Quelle est la formule de la concentration molaire (C) d'une solution ?","option_a":"C = n\/V","option_b":"C = m\/V","option_c":"C = V\/n","option_d":"C = m × V","option_e":"","option_f":"","bonne_reponse":"a","explication":"La concentration molaire se calcule par C = n\/V, où n est la quantité de matière (en moles) et V le volume de la solution (en litres).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"C = n\/V\", \"b\": \"C = m\/V\", \"c\": \"C = V\/n\", \"d\": \"C = m × V\"}}","_debug_options_count":4},{"id":24197,"question":"Un catalyseur augmente la vitesse d'une réaction chimique sans être consommé.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Un catalyseur accélère une réaction en abaissant l'énergie d'activation, sans être modifié ni consommé au cours de la réaction.","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":24198,"question":"Quel est le nombre d'oxydation du soufre dans l'ion sulfate (SO₄²⁻) ?","option_a":"+2","option_b":"+4","option_c":"+6","option_d":"+8","option_e":"","option_f":"","bonne_reponse":"c","explication":"Dans SO₄²⁻, l'oxygène a un nombre d'oxydation de -2. L'équation est : S + 4×(-2) = -2 ⇒ S = +6.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"+2\", \"b\": \"+4\", \"c\": \"+6\", \"d\": \"+8\"}}","_debug_options_count":4},{"id":24199,"question":"La dissolution du sel (NaCl) dans l'eau est un processus exothermique.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"La dissolution de NaCl dans l'eau est globalement endothermique (absorption de chaleur), bien que la dissociation des ions soit exothermique.","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":24200,"question":"Quelle est la formule de la constante d'équilibre (K) pour la réaction : aA + bB ⇌ cC + dD ?","option_a":"K = [C]^c × [D]^d \/ [A]^a × [B]^b","option_b":"K = [A]^a × [B]^b \/ [C]^c × [D]^d","option_c":"K = [C] + [D] \/ [A] + [B]","option_d":"K = [A] × [B] \/ [C] × [D]","option_e":"","option_f":"","bonne_reponse":"a","explication":"La constante d'équilibre K s'exprime par le rapport des concentrations des produits sur les réactifs, chacune élevée à la puissance de leur coefficient stœchiométrique.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"K = [C]^c × [D]^d \/ [A]^a × [B]^b\", \"b\": \"K = [A]^a × [B]^b \/ ","_debug_options_count":4},{"id":24201,"question":"Un acide de Brønsted-Lowry est une espèce chimique capable de donner un proton (H⁺).","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Oui, selon la théorie de Brønsted-Lowry, un acide est une espèce chimique donneuse de protons (H⁺).","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":24202,"question":"Quelle est la masse molaire du glucose (C₆H₁₂O₆) ?","option_a":"162 g\/mol","option_b":"180 g\/mol","option_c":"198 g\/mol","option_d":"200 g\/mol","option_e":"","option_f":"","bonne_reponse":"b","explication":"La masse molaire se calcule : (6×12) + (12×1) + (6×16) = 72 + 12 + 96 = 180 g\/mol.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"162 g\/mol\", \"b\": \"180 g\/mol\", \"c\": \"198 g\/mol\", \"d\": \"200 g\/mol\"}","_debug_options_count":4},{"id":24203,"question":"La conductivité électrique d'une solution dépend uniquement de la concentration en ions.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"La conductivité dépend aussi de la nature des ions, de leur mobilité et de la température. Une solution très concentrée peut avoir une conductivité faible si les ions sont peu mobiles.","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}]