题目

    Small children often laugh at the short ones or at someone who isn’t dressed as well as they are.But as they grow up,they learn not to hurt people’s feelings by laughing at their problems.They learn to laugh at other things.Most important,they learn to laugh at themselves.     Suppose you’re playing a game.You make a mistake and lose.Do you become angry? Or can you laugh at yourself and hope to do better next time? Suppose you are at a special dinner.You at times spill(溅)some food.Why keep worrying about how clumsy (笨拙)you look? Why not laugh it off an工业上利用氧化铝基废催化剂(主要成份为Al2O3,少量Pd)回收Al2(SO4)3及Pd 流程如图:说明:上述流程中焙烧温度不宜过高,否则会导致硫酸铵固体的分解。(1)焙烧时产生气体X的结构式为________。(2)水浸分离中,滤渣Pd的颗粒比较大,一般可以采用的分离方法是_________ (填字母)A.过滤 B.抽滤 C.倾析 D.渗析(3)写出酸浸时发生反应的离子方式______(已知氯钯酸为弱酸)(4)某同学在实验室用如下图所示装置完成Pd的热还原实验,并计算滤渣中 (NH4)2PdCl6的百分含量(滤渣中的杂质不参与热还原反应)。①写出热还原法过程中发生反应的化学方程式________。②i.将石英玻璃管中(带开关;K1和K2)(设为装置A )称重,记为mi g。将滤渣 [(NH4)2PdCl6]装入石英玻璃管中,再次将装置A称重,记为m2 g。ii.连接好装置后,按d→ → →b→ →e(填标号)顺序进行实验。_______ a.关闭K1和K2 b.熄灭酒精灯 c.点燃酒精灯,加热d.打开K1和K2 e.称量A f.缓缓通入H2 g.冷却至室温iii.重复上述操作步骤,直至A恒重,记为m3g。③根据实验记录,计算滤渣中(NH4)2PdCl6的百分含量__________[列式表示,其中(NH4)2PdCl6相对分子质量为355]。④实验结束时,发现硬质试管右端有少量白色固体,可能是____(填化学式),这种情况导致实验结果_________(填“偏高”、“偏低”、“无影响”)
英语 试题推荐