【单选题】一定体积的KMnO 4 溶液恰好能氧化一定质量的KHC 2 O 4 ·H 2 C 2 O 4 ·2H 2 O。若用0.100 0 mol/L的NaOH溶液中和相同质量的KHC 2 O 4 ·H 2 C 2 O 4 ·2H 2 O,所需NaOH溶液的体积恰好为KMnO 4 溶液的6倍,则KMnO 4 溶液的浓度(mol/L)为( ) 提示:①H 2 C 2 O 4 是二元弱酸 ②10[KHC 2...
【单选题】听力原文:W: Hey, Margo! Do you know where the scissors are? M: Aren't they in the desk drawer? W: That's the first place I looked. What can we infer from the conversation?
A.
The woman will search the desk drawer.
B.
The scissors are in the desk drawer.
C.
The woman has searched the desk drawer.
D.
The scissors have been found.
【判断题】Margo did not encourage Sheila to return the affairs of Bob.
【单选题】Don't ask Margo about last night. It will embarrass her.
B.
Really? Did she have a good time?
【单选题】0 2 和CO 2 是动植物生命活动中不可缺少的两种气体,它们的相同点是 ( )
【单选题】一定体积的KMnO 4 溶液恰好能氧化一定质量的KHC 2 O 4 ·H 2 C 2 O 4 ·2H 2 O。若用0.100 0 mol/L的NaOH溶液中和相同质量的KHC 2 O 4 ·H 2 C 2 O 4 ·2H 2 O,所需NaOH溶液的体积恰好为KMnO 4 溶液的3倍,则KMnO 4 溶液的浓度(mol/L)为 提示:①H 2 C 2 O 4 是二元弱酸 ②10[KHC 2 O 4 ...
【单选题】25℃时,下列说法正确的是
A.
pH =8.3的NaHCO 3 溶液:c( Na + )>c( HC )>c(C )>c( H 2 CO 3 )
B.
中和同浓度同体积的盐酸和醋酸,消耗的NaOH的物质的量不相同
C.
用一定浓度的NaOH溶液滴定氢氟酸,当pH =6时,溶液中c(F — )—c(Na + )=9.9×l0 —7 mol/L
D.
用NaOH溶液滴定HCI与CH 3 COOH的混合溶液至中性时,溶液中的酸被完全中和
【单选题】( 2018· 广西中考真题) 下表是 NaCl和Na 2 CO 3 在不同温度下的溶解度,下列说法中不正确的是( ) 温度/°C 0 10 20 30 40 溶解度/g NaCl 35.0 35.5 36.0 36.5 37.0 Na 2 CO 3 6.0 10.0 18.0 36.5 50.0
B.
生活在盐碱湖附近的人们习惯 “夏天晒盐、冬天捞碱”
C.
40℃时,5gNaCl中加10g水可得溶质质量分数为26.3%的溶液
D.
40℃时,9g Na 2 CO 3 中加20g水,充分溶解后再降温到10℃,析出固体的质量为7g
【单选题】What can be inferred from Margo Veners words?
A.
Physicians' experience helps to ensure a residency position.
B.
Being a doctor is not as splendid as most people think.
C.
Becoming a doctor takes as long as 30-40 years.
D.
Training is the basis of a successful career.