Quiz interactif : Acides, bases et pH — Niveau Bac Sciences

Question 1 sur 10 10:00

[{"id":31858,"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":"HCl est un acide fort qui se dissocie totalement : [H3O+] = 0,01 mol\/L. pH = -log(0,01) = 2.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31859,"question":"Un indicateur coloré est une substance qui change de couleur en fonction de la concentration en ions OH-.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"B","explication":"Un indicateur coloré change de couleur en fonction du pH, donc de la concentration en ions H3O+ ou OH-.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31860,"question":"Quel couple acide\/base correspond à l’acide acétique CH3COOH ?","option_a":"CH3COOH\/CH3COO-","option_b":"CH3COO-\/CH3COOH","option_c":"H3O+\/H2O","option_d":"NH4+\/NH3","option_e":"","option_f":"","bonne_reponse":"A","explication":"L’acide acétique CH3COOH donne son couple acide\/base avec son ion conjugué CH3COO-.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31861,"question":"Une solution a un pH de 9. Comment peut-on la qualifier ?","option_a":"Acide","option_b":"Basique","option_c":"Neutre","option_d":"Saturée","option_e":"","option_f":"","bonne_reponse":"B","explication":"Un pH de 9 est supérieur à 7, donc la solution est basique.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31862,"question":"La réaction entre un acide et une base produit toujours de l’eau et un sel.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"A","explication":"La réaction acido-basique produit de l’eau et un sel, mais ce n’est pas systématique (ex : réaction avec NH3).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31863,"question":"Quel est l’ion responsable de l’acidité d’une solution ?","option_a":"H3O+","option_b":"OH-","option_c":"Cl-","option_d":"Na+","option_e":"","option_f":"","bonne_reponse":"A","explication":"L’ion H3O+ (ou H+) est responsable de l’acidité d’une solution.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31864,"question":"Une solution de soude (NaOH) a un pH de 13. Quelle est sa concentration en ions OH- ?","option_a":"0,1 mol\/L","option_b":"1 mol\/L","option_c":"10 mol\/L","option_d":"0,01 mol\/L","option_e":"","option_f":"","bonne_reponse":"A","explication":"pH = 13 ⇒ pOH = 1 ⇒ [OH-] = 10^-1 = 0,1 mol\/L.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31865,"question":"Le bleu de bromophénol est un indicateur coloré qui vire au jaune pour pH \u003C 3 et au bleu pour pH \u003E 4,6.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"A","explication":"Le bleu de bromophénol vire au jaune en milieu acide (pH \u003C 3) et au bleu en milieu basique (pH \u003E 4,6).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31866,"question":"Quel est le pH d’une solution d’acide chlorhydrique à 0,0001 mol\/L ?","option_a":"1","option_b":"2","option_c":"3","option_d":"4","option_e":"","option_f":"","bonne_reponse":"D","explication":"pH = -log(0,0001) = 4.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":31867,"question":"Une solution neutre a toujours un pH égal à 7 à 25°C.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"A","explication":"À 25°C, une solution neutre a un pH de 7, mais cette valeur varie avec la température.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0}]