300多年前，著名化学家波义耳发现了铁盐与没食子酸的显色反应，并由此发明了蓝黑墨水．没食子酸的结构式如图所示：_刷题宝

题干

300多年前，著名化学家波义耳发现了铁盐与没食子酸的显色反应，并由此发明了蓝黑墨水．没食子酸的结构式如图所示：

上一题下一题 0.0难度选择题更新时间:2019-01-10 06:42:36

答案(点此获取答案解析）

同类题1

俗话说“下雪不冷，化雪冷”．这是因为（）

同类题2

请你结合如图装置图回答问题．（友情提示：以下所选装置均填装置代号）

同类题3

A School Report
Name: Andy Smith(An Australian boy)
Grade: 7
School: Moonlight Secondary School
Term ending: 1 July
Subjects:
Chinese: He is a little weak in it, but he is trying his best all the time.
Maths: He can work out many difficult problems. But he is someitmes careless.
English: He is the best in the class. Keep it.
History: He is not very good at this. But he is doing better than before.
Geography: He knows a lot about it. It’s one of his favourite.
Music: He sings well, but he seldom sings.
Class teacher: Bill
Principal: Thomas Allan Green
School reopens: 1 September

同类题4

如图，将矩形ABCD绕点A顺时针旋转到矩形AB′C′D′的位置，旋转角为α（0°＜α＜90°），若∠BAD′=70°，则α的大小为（）

同类题5

墨墨和朋友在一起踢足球时不小心摔倒，将膝盖擦伤，他为了将一杯9g质量分数为10%的NaCl溶解，配制成0.9%的生理盐水（主要成分为NaCl溶液）来清洗伤口，则需要水的质量为（　　）

小学学科试题库

初中学科试题库

高中学科试题库