题干

下列说法正确的是                                      (   )


 
  

A:向CH2BrCOOH中加足量的氢氧化钠溶液并加热: CH2BrCOOH+2OH→CH2OHCOO-+ Br-+ H2O

B:25℃时,将20mL 0.1mol·L-1H2SO4溶液和30mL 0.15mol·L-1NaOH溶液混合,若混合后溶液体积不变,则混合溶液的pH为11

C:将10mL 0.1mol·L-1KAl(SO42溶液和10mL 0.2mol·L-1Ba(OH)2溶液混合,得到的沉淀中Al(OH)3和BaSO4的物质的量之比为1:2

D:浓度均为0.1mol·L-1的醋酸和CH3COONa溶液等体积混合,溶液中有下列关系:

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A

同类题3

请认真阅读下面短文,从短文后各题所给的A、B、C、D四个选项中,选出最佳选项。

    Your body is special – no two people in the world are alike, Although you are different from everyone else, you have exactly the same body parts as the people around you, doing different jobs that keep all of us alive.
    What is inside my head ?
    Your head houses the most valuable part of your body – your brain. As you are reading, your eyes send pictures to your brain which makes meaning from what you see. Your brain helps you to remember and think, and makes sure your body is doing what it should.
    What is my skin(皮肤) for ?
    Your skin covers your body. In most parts of your body, the skin is just as thick as half a centimeter. If you have your skin cut, it will have a quick cure and stop viruses from getting into your body. Your skin also helps you feel the heat and coldness of the environment around you. Hair grows from inside the skin. When you feel hot, extra heat comes out through your skin. As a result, your body temperature drops.
    How do I move ?
    Muscles(肌肉) are found in most parts of your body. They work with your bones to help you move – whenever you cry or smile, eat or speak, walk or dance, etc.
    Why do I breathe ?
    Your body needs to take in oxygen from the air and give out the unwanted carbon dioxide in the body. When you breathe, air comes through your nose and mouth into your lungs(肺) where oxygen flows to different parts of your body.
    What makes me sneeze ?
    When dust or a strong smell gets into your nose, you sneeze. This is the way your body cleans up the dust in your nose. Your lungs push out the air and try to clear your nose.
    What does my heart do ?
    Your heart is a very special muscle. It is slightly bigger than your fist (拳头) and grows bigger as you do. If you place your hand on your heart, you will feel your heart beating which forces blood to move around your body.