Quiz — Série pH des solutions aqueuses (2).pdf

Question 1 sur 5 10:00

[{"id":2974,"question":"Quel est le pH d'une solution dont la concentration en ions H\u003Csub\u003E3\u003C\/sub\u003EO\u003Csup\u003E+\u003C\/sup\u003E est de 10\u003Csup\u003E-3\u003C\/sup\u003E mol\/L ?","option_a":"pH = 3","option_b":"pH = 11","option_c":"pH = -3","option_d":"pH = 10\u003Csup\u003E-3\u003C\/sup\u003E","option_e":"","option_f":"","bonne_reponse":"a","explication":"Le pH se calcule avec la formule pH = -log[H\u003Csub\u003E3\u003C\/sub\u003EO\u003Csup\u003E+\u003C\/sup\u003E]. Ici, pH = -log(10\u003Csup\u003E-3\u003C\/sup\u003E) = 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 = 11\", \"c\": \"pH = -3\", \"d\": \"pH = 10\u003Csup\u003E-3\u003C\/su","_debug_options_count":4},{"id":2975,"question":"Quel indicateur coloré vire au jaune en milieu acide et au bleu en milieu basique ?","option_a":"Phénolphtaléine","option_b":"Bleu de bromothymol","option_c":"Hélianthine","option_d":"Rouge de méthyle","option_e":"","option_f":"","bonne_reponse":"c","explication":"L'hélianthine (ou méthylorange) est un indicateur qui change de couleur dans la zone de pH 3,1 à 4,4, passant du rouge au jaune en milieu acide.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"Phénolphtaléine\", \"b\": \"Bleu de bromothymol\", \"c\": \"Hélianthin","_debug_options_count":4},{"id":2976,"question":"Si on dilue une solution acide, que se passe-t-il pour son pH ?","option_a":"Le pH augmente","option_b":"Le pH diminue","option_c":"Le pH reste constant","option_d":"Le pH devient négatif","option_e":"","option_f":"","bonne_reponse":"a","explication":"Diluer une solution acide réduit la concentration en ions H\u003Csub\u003E3\u003C\/sub\u003EO\u003Csup\u003E+\u003C\/sup\u003E, ce qui augmente le pH (la solution devient moins acide).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Le pH augmente\", \"b\": \"Le pH diminue\", \"c\": \"Le pH reste constant","_debug_options_count":4},{"id":2977,"question":"Calculez le pH d'une solution de soude (NaOH) de concentration 10\u003Csup\u003E-2\u003C\/sup\u003E mol\/L.","option_a":"pH = 2","option_b":"pH = 12","option_c":"pH = 10\u003Csup\u003E-2\u003C\/sup\u003E","option_d":"pH = 0","option_e":"","option_f":"","bonne_reponse":"b","explication":"La soude est une base forte. [OH\u003Csup\u003E-\u003C\/sup\u003E] = 10\u003Csup\u003E-2\u003C\/sup\u003E mol\/L, donc [H\u003Csub\u003E3\u003C\/sub\u003EO\u003Csup\u003E+\u003C\/sup\u003E] = 10\u003Csup\u003E-14\u003C\/sup\u003E\/10\u003Csup\u003E-2\u003C\/sup\u003E = 10\u003Csup\u003E-12\u003C\/sup\u003E mol\/L. pH = -log(10\u003Csup\u003E-12\u003C\/sup\u003E) = 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 = 10\u003Csup\u003E-2\u003C\/sup\u003E\", \"d\": \"pH = ","_debug_options_count":4},{"id":2978,"question":"Quel est le rôle d'un indicateur coloré dans une titration acido-basique ?","option_a":"Il neutralise la solution","option_b":"Il change de couleur à l'équivalence","option_c":"Il augmente la concentration en ions","option_d":"Il diminue le pH","option_e":"","option_f":"","bonne_reponse":"b","explication":"Un indicateur coloré permet de visualiser l'équivalence lors d'une titration en changeant de couleur lorsque le pH atteint une valeur spécifique.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Il neutralise la solution\", \"b\": \"Il change de couleur à l'équi","_debug_options_count":4}]