Maîtrisez le pH et ses applications en chimie !

Question 1 sur 10 10:00

[{"id":12648,"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 égal à 7, ce qui correspond à une concentration égale en ions H+ et OH-.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":12649,"question":"Le BBT est un indicateur coloré qui devient bleu en milieu basique.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"A","explication":"Le BBT (Bleu de Bromothymol) devient bleu en milieu basique (pH \u003E 7) et jaune en milieu acide (pH \u003C 6).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":12650,"question":"Quelle est la formule du pH pour une solution diluée ?","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 est défini par 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":12651,"question":"Une solution a un pH de 3. Comment la qualifier ?","option_a":"Acide","option_b":"Basique","option_c":"Neutre","option_d":"Amphotère","option_e":"","option_f":"","bonne_reponse":"A","explication":"Un pH de 3 est inférieur à 7, donc la solution est acide.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":12652,"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":"Le pH d'une solution ne peut pas être négatif car la concentration en ions H+ ne peut pas dépasser 1 mol\/L.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":12653,"question":"Quel indicateur coloré devient rouge en milieu acide ?","option_a":"Phénolphtaléine","option_b":"BBT","option_c":"Hélianthine","option_d":"Bleu de thymol","option_e":"","option_f":"","bonne_reponse":"C","explication":"L'hélianthine (ou méthylorange) devient rouge en milieu acide (pH \u003C 3,1) et jaune en milieu basique.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":12654,"question":"Calculez le pH d'une solution dont [H+] = 10^-5 mol\/L.","option_a":"5","option_b":"9","option_c":"-5","option_d":"0,5","option_e":"","option_f":"","bonne_reponse":"A","explication":"Le pH est calculé par pH = -log(10^-5) = 5.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":12655,"question":"Une solution de pH 12 est-elle basique ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"A","explication":"Un pH de 12 est supérieur à 7, donc la solution est basique.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":12656,"question":"Quelle est la concentration en ions H+ d'une solution de pH 4 ?","option_a":"10^-4 mol\/L","option_b":"10^4 mol\/L","option_c":"4 mol\/L","option_d":"0,4 mol\/L","option_e":"","option_f":"","bonne_reponse":"A","explication":"La concentration en ions H+ est donnée par [H+] = 10^-pH = 10^-4 mol\/L.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":12657,"question":"Le pH d'une solution peut-il varier avec la dilution ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"A","explication":"Le pH d'une solution varie généralement avec la dilution, sauf pour les solutions tampons.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0}]