【单选题】—What is your father like? —__________. [ ]
C.
He is tall and medium build
D.
He is mad about football
【单选题】已知 : (1) CaC 2 O 4 = Ca 2+ + C 2 O 4 2- K ɵ =2.3×10 -9 (2) HAc = H + + Ac - K ɵ =1.8×10 -5 (3) HC 2 O 4 - = H + + C 2 O 4 2- K ɵ =6.4×10 -5 则可计算反应 CaC 2 O 4 + HAc = Ca 2+ + HC 2 O 4 - +...
【单选题】Speak a: Merry Christmas! Speak b:________________
【单选题】常温下已知电离常数: K b (NH 3 ·H 2 O) = 1.8 × 10 - 5 ; K a1 (H 2 C 2 O 4 ) = 5.9 × 10 - 2 , K a2 (H 2 C 2 O 4 ) = 6.4 × 10 - 5 。下列说法正确的是 ( )
A.
. (NH 4 ) 2 C 2 O 4 溶液中 , c (NH ) = 2 c (C 2 O )
B.
.等物质的量浓度的氨水和 H 2 C 2 O 4 溶液等体积混合,所得溶液呈碱性
C.
. pH = 11 的氨水和 pH = 3 的 H 2 C 2 O 4 溶液等体积混合,所得溶液呈酸性
D.
.用 H 2 C 2 O 4 溶液中和氨水至中性时,溶液中 c (NH ) = 2 c (C 2 O ) + c (HC 2 O )
【单选题】Speaker A: Merry Christmas! Speaker B:________________
【简答题】听小对话,选答案。 1. What is Uncle Wang? A. He is a teacher. B. He is a doctor. C. He is an assistant 2. What’s the girl’s favorite? A. Man and Nature. B. News Report. C. Animal World 3. What does Brad want t...
【单选题】根据上述资料,下列说法中,正确的有( )。
B.
常发公司对于设置的“应收账款”账户,贷方余额表示应付账款
C.
常发公司如果不设置预收账款,可以在“预付账款”的贷方核算
D.
常发公司预收账款只能在“预收账款”账户中核算
【简答题】已知 H 2 C 2 O 4 的 K a1 ө (H 2 C 2 O 4 )=6.5 × 10 -2 , K a2 ө (H 2 C 2 O 4 )=6.1 × 10 -5 ,则 HC 2 O 4 - K b ө