常温下,用0.1mol•L﹣1 NaOH溶液滴定20mL 0.1mol•L﹣1CH3COOH溶液的滴定曲线如图所示.下列说法正确的是( )
A:点①所示溶液中:c(Na+)>c(CH3COO﹣)>c(CH3COOH)>c(H+)>c(OH﹣)
B:点②所示溶液中:c(Na+)+c(H+)=c(CH3COO﹣)+c(CH3COOH)+c(OH﹣)
C:点③所示溶液中:c(CH3COO﹣)>c(Na+)>c(OH﹣)>c(H+)
D:在整个滴定过程中:溶液中C(CH3COOH)C(CH3COO-)·C(H+)始终不变
用氯化铵(NH4Cl)浓溶液去除某金属表面氧化物(氧化物化学式用MO表示),其反应原是为:2NH4Cl+MOMCl2+2NH3↑+X,则物质X的化学式为____
关于北方地区和南方地区的说法,不正确的是( )
The little girl is not to take care of herself. So her mother looks after her.