问题 选择题

下列关于物质的量浓度表述中正确的是(  )

A.0.3 mol•L-1 Na2SO4溶液中含有Na+

SO2-4
总物质的量为0.9 mol

B.用1 L水吸收22.4 L氨气所得氨水的浓度是1 mol•L-1

C.50mL 1 mol•L-1的KCl溶液和100mL 0.25 mol•L-1MgCl2溶液中,Cl-的物质的量浓度相等

D.10℃时0.35 mol•L-1的KCl饱和溶液100 mL,蒸发掉5 g水,再冷却到10℃时,它的物质的量浓度仍为0.35 mol•L-1

答案

A、溶液中含有Na+

SO2-4
总物质的量与溶液体积有关,溶液的体积未知,离子的物质的量不一定,若溶液为1L,0.3 mol•L-1 Na2SO4溶液中含有Na+
SO2-4
总物质的量为0.9mol,故A错误;

B、溶液的体积不是1L,氨气所处的状态未定,氨气的物质的量不一定是1mol,所得氨水的浓度不一定是1 mol•L-1,故B错误;

C、1 mol•L-1的KCl溶液中Cl-的物质的量浓度为1mol/L,0.25 mol•L-1MgCl2溶液中Cl-的物质的量浓度为0.5mol/L,Cl-的物质的量浓度不相等,故C错误;

D、10℃KCl饱和溶液100 mL,蒸发掉5g水,再冷却到10℃时,溶液仍是饱和溶液,温度相同溶解度相同,溶液的浓度相同仍是物质的量浓度仍为0.35 mol/L,故D正确.

故选:D.

完形填空

任务型阅读。 (10分)

As young students, you have many dreams. These dreams can be very big, such as winning the Nobel Prize; they can also be small, such as becoming one of the best students in your class.

Once you find a dream, what do you do with it? Do you ever try to make your dream real?

Andrew Matthews, an Australian writer, tells us that making your dreams real is life’s biggest challenge (挑战). You may think you’re not very good at some school subjects, or that (1) to become a writer is difficult for you. Those kinds of ideas stop you from realizing (实现) your dream.

In fact, everyone can realize his dream. The first thing you must do is to remember what your dream is. Don’t let it leave your heart. (2)Keep telling yourself what you want every day and then your dream will come true faster. You should know that a big dream is, in fact, made up of (由…组成) many small dreams.

You must also never give up your dream. There will be difficulties on the road to your dreams. But the biggest difficulty comes from yourself. You need to decide what is the most important. (3)You shouldn’t watch TV. You’d better study instead. It will help you to get better exam results.

小题1:回答问题:What does Andrew Matthews do?

He _______________________________________________________.

小题2: 在文中找出realize的同义词组:________ ________

小题3:根据(1)处完成下面的句子。(每空一词)

It’s ________ for you to ________ a writer.

小题4: 将(2)处翻译成汉语。

________________________________________________________________

小题5: 根据(3)处完成下面的句子。(每空一词)

You’d better study instead of ________ ________, so you will get good exam results.

判断题