Maîtrisez le pH et les solutions acido-basiques — Quiz interactif

Question 1 sur 10 10:00

[{"id":62822,"question":"Quel est le pH d'une solution neutre ?","option_a":"0","option_b":"7","option_c":"14","option_d":"10","option_e":"","option_f":"","bonne_reponse":"B","explication":"Une solution neutre a un pH de 7, ce qui signifie qu'elle contient autant d'ions H+ que d'ions OH-.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62823,"question":"Le jus de citron a un pH d'environ 2. Quelle affirmation est correcte ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"A","explication":"Le jus de citron est acide (pH \u003C 7), donc l'affirmation est correcte.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62824,"question":"Quel indicateur coloré devient rose en milieu basique ?","option_a":"Bleu de bromothymol","option_b":"Phénolphtaléine","option_c":"Papier pH universel","option_d":"Rouge de méthyle","option_e":"","option_f":"","bonne_reponse":"B","explication":"La phénolphtaléine prend une couleur rose en milieu basique (pH \u003E 8).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62825,"question":"Si une solution a un pH de 12, comment peut-on la qualifier ?","option_a":"Acide","option_b":"Neutre","option_c":"Basique","option_d":"Diluée","option_e":"","option_f":"","bonne_reponse":"C","explication":"Un pH de 12 indique une solution basique (pH \u003E 7).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62826,"question":"L'eau pure a toujours un pH de 7, même après ajout d'un peu d'acide.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"B","explication":"L'ajout d'acide fait baisser le pH de l'eau pure en dessous de 7, car elle devient acide.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62827,"question":"Quelle est la formule permettant de calculer le pH d'une solution acide ?","option_a":"pH = -log[H+]","option_b":"pH = log[H+]","option_c":"pH = [H+]","option_d":"pH = 1\/[H+]","option_e":"","option_f":"","bonne_reponse":"A","explication":"Le pH se calcule avec la formule pH = -log[H+], où [H+] est la concentration en ions hydrogène.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62828,"question":"Un indicateur coloré est une substance qui change de couleur en fonction du pH.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"A","explication":"C'est la définition même d'un indicateur coloré : il change de couleur selon le pH de la solution.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62829,"question":"Quel est le pH d'une solution de soude (NaOH) à 0,01 mol\/L ?","option_a":"2","option_b":"7","option_c":"12","option_d":"14","option_e":"","option_f":"","bonne_reponse":"C","explication":"La soude est une base forte. Une solution de NaOH à 0,01 mol\/L a un pH de 12 (pH = 14 + log[OH-] = 14 - 2 = 12).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62830,"question":"Le papier pH universel permet de mesurer précisément le pH d'une solution.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"B","explication":"Le papier pH universel donne une estimation du pH (par plage de couleurs), mais n'est pas aussi précis qu'un pH-mètre.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":62831,"question":"Si on dilue une solution acide, son pH :","option_a":"Augmente","option_b":"Diminue","option_c":"Reste inchangé","option_d":"Devient négatif","option_e":"","option_f":"","bonne_reponse":"A","explication":"Diluer une solution acide réduit sa concentration en ions H+, ce qui fait augmenter son pH (elle devient moins acide).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0}]