题干

某溶液中可能含有H+、Na+、NH4+、Mg2+、Fe3+、Al3+、SO42-、CO32-等离子。当向该溶液中加入一定物质的量浓度的NaOH溶液时,发现生成沉淀的物质的量随NaOH溶液的体积变化的图像如图所示。下列说法正确的是( )


A:原溶液中含有的阳离子是H+、NH4+、Mg2+、Al3+

B:原溶液中一定含有SO42-和Na+

C:原溶液中含有的Fe3+和Al3+的物质的量之比为1:1

D:反应最后形成的溶液中含有的溶质为Na2SO4

上一题 下一题 0.0难度 选择题 更新时间:2018-05-30 05:30:10

答案(点此获取答案解析)

C

同类题1

阅读理解

    We ate on the go more than ever before. Here are three health apps that can help you better manage your health when you pursue your dreams.

⑴Doctors On Demand

    Doctors On Demand enables you to visit a doctor without ever leaving your home, helping you use a computer, tablet or smart phone to have a doctor video chat with you. The service will help you locate and connect you to licensed doctors, psychologists, pediatricians (儿科医生) and more. Fees can be paid with HAS&FSA. It costs $40 for 15 minutes with a doctor or $50 for 20 minutes with a psychologist.

⑵Text4baby

    I'm a big fan of Text4baby for a few reasons. The free service for pregnant women and new moms works by sending text messages to your smart phone three times a week with information about how to have a healthy pregnancy and baby. And the messages are timed to the pregnant woman's due date or the baby's date of birth, sending tips that are relevant to where a mother is in her pregnancy or where a baby is in stages of development. Tips range from breastfeeding to car seat safety to reminders about exercise, nutrition and more. The service combines interactive text messages, an app, video and web content in English and Spanish. Sign up by texting BABY to 511-411 or by downloading the app.

⑶RISE

    RISE, an app available on iPhone(coming to Android in 2016), pairs you up with (与……绑定) a registered dietitian to improve your diet and reach health goals. You share photos of your meals and your exercise for the day with your coach, who then looks for areas where you can improve and gives advice, helps you set goals and is there to pat you on the back virtually(虚拟地) when you hit a milestone. What's also great is that you can text as much as you want with your dietitian and there is no need to go into an office. Fees for this service range from $9 per month to $50 a month. There is a free 7-day trial so you can try it out for a week to see if it's fit for you.