题干

实验室有四个药品橱,已存放如下药品:

①实验室新购进一些木炭,应将它存放在____橱中(填“甲”、“乙”、“丙”或“丁”)。

②甲橱红磷在氧气中燃烧的主要现象是____

③乙橱中的固体物质可以作干燥剂的是____(写化学式)。

④丙橱中药品都属于____类别(填“酸”、“盐”或“单质”)。

⑤丁橱的物质露置于空气一段时间后(不考虑水分挥发),说法正确的是____

I. 溶质质量都减少                II. 溶剂质量都增大

Ⅲ. 溶质质量分数都减少            Ⅳ. 溶液质量都减少

上一题 下一题 0.0难度 选择题 更新时间:2013-04-24 09:16:00

答案(点此获取答案解析)

甲,产生白烟、放热,NaOH,盐,III

同类题1

课内经典文段阅读。

    ①父亲的准备是十分漫长的。他今天从地里检回一块砖,明天可能又捡进一片瓦,再就是往一个黑瓦罐里塞角票。虽然这些都很微不足道,但他做得很认真。

    ②于是,一年中他七个月种田,四个月去山里砍采,半个月在大溪滩上检屋基卵石,剩下半个月用来过年、编草鞋。

    ③大热天父亲挑一担谷子回来,身上淌着一片大汗,顾不得措一把,就往门口的台阶上一坐。他开始“磨刀”。“磨刀”就是过烟瘾。烟吃饱了“‘刀”快,活做得去。

    ④台阶旁栽着一棵桃树,桃树为台阶遮出一片绿荫。父亲坐在绿荫里,能看见别人家高高的台阶,那里栽着几裸柳树,柳树枝老是摇未摇去,却摇不散父亲那专注的目光。这时,一片片旱烟雾在父亲头上飘来飘去。

    ⑤父亲磨好了“刀”。去烟灰时,把烟枪的铜盏对着青石板嘎嘎地敲一敲,就匆忙地下田去。

    ⑥冬天,晚稻收仓了,春花也种下地,父亲穿着草鞋去山里砍柴。他砍柴一为家烧,二为卖钱,一元一担。父亲一天砍一担半,得一元五角。那时我不知道山有多远,只知道鸡叫三遍时父亲出发,黄昏贴近家门口时归来,把柴靠在墙根上,很疲倦地坐在台阶上,把已经磨穿了底的草鞋脱下来,垒在门墙边。一个冬天下来,破草鞋堆得超过了台阶。

    ⑦父亲就是这样准备了大半辈子。塞角票的瓦罐满了几次,门口空地上鹅卵石堆得小山般高。他终于觉得可以造屋了,便选定一个日子,破土动工。

同类题5

   (One day Alice runs after a strange rabbit and comes into a deep hole. She becomes smaller when she wakes up the next day. She finds herself in a wonderland with many amazing things inside.)
   The Caterpillar(毛毛虫) and Alice looked at each other for some time in silence. At last the Caterpillar took the pipe out of its mouth, and said to her in a tired, sleepy voice.
   “Who are YOU?” said the Caterpillar.
   This opening for a talk couldn’t make Alice at ease. Alice replied, rather shyly, “I----I hardly know, sir, just at present ----at least I know who I was when I got up this morning, but I think I must have been changed several times since then.”
   “What do you mean by that?” said the Caterpillar, “Explain yourself!”
   “I can’t explain MYSELF. I’m afraid, sir.” said Alice, “because I’m not myself, you see.”
   “I don’t see.” said the Caterpillar.
   “I’m afraid I can’t put it more clearly.” Alice replied very politely, “for I can’t understand it myself. And being so many different sizes in a day is very puzzling.”
   “It isn’t.” said the Caterpillar.
   “Well, perhaps you haven’t found it so yet.” said Alice. “But when you have to turn into a chrysalis(蛹,茧)----you will some day, you know ----and then after that into a butterfly, I think you’ll feel it a little stranger, won’t you?”
   “Not a bit.” said the Caterpillar.
   “Well, perhaps your feelings may be different.” said Alice. “All I know is, it would make ME feel very strange.”
   “You!” said the Caterpillar scornfully. “Who are YOU?” The question brought them back again to the beginning of the talk. Alice felt a little angry because the Caterpillar was making such VERY short sentences. She drew herself up and said very seriously, “I think you ought to tell me who YOU are first.”
   “Why?” said the Caterpillar.
   Here was another puzzling question. As Alice could not think out any good reason, and as the Caterpillar seemed to be very unpleasant, she turned away.
   “Come back!” the Caterpillar called after her. “I’ve something important to tell you!”
   This certainly gave Alice some hope. Alice turned and came back again.