【单选题】已知NaH 2 PO 4 溶液呈酸性,在水溶液中存在如下水解平衡:H 2 PO - 4 +H 2 O H 3 PO 4 +OH - ,现将0.1 mol·L -1 NaH 2 PO 4 溶液稀释后,增大的是( )
【简答题】Po: uh oh~~ahhhh~~~~ ohhhhh~ What's going on ... Where I am ... What are you 1) ... oh ... ok ... sorry ... I just wanted to see who the dragon warrior was. Wugui: How interesting tigeree: are ...
【简答题】牙齿的损坏实际是牙釉质[Ca 5 (PO 4 ) 3 OH]溶解的结果,在口腔中存在如下平衡:Ca 5 (PO 4 ) 3 OH?5Ca 2+ +3PO 4 3- +OH - 当糖附在牙齿上发酵时会产生H + ,试运用化学平衡理论说明经常吃糖对牙齿的影响.
【单选题】听力原文:W: Oh, Professor Jackson, I was wondering well, Oh,...well, if uh...if you have a chance yet to look at my thesis proposal. M: Well, I know you gave it to me over a week ago, but to be honest, I ...
A.
He means that he didn't know the thesis proposal.
B.
He means that he hasn't have time to read the proposal.
C.
He means that he will not help her read the proposal.
D.
He means that she'd have given it to him earlier.
【单选题】听力原文:G Hi there! Uh, looking for some help? S Oh! Yeah, I uh ... was just wandering around the campus trying to get acquainted with it. G Well, I can give you some information if you would like. Im a ...
A.
To invite him to a football game.
B.
To see if he has any questions.
C.
To ask if he would like to be a guide.
D.
To ask the student for directions.
【简答题】(3分)牙齿的损坏实际是牙釉质[Ca 5 (PO 4 ) 3 OH]溶解的结果,在口腔中存在如下平衡:Ca 5 (PO 4 ) 3 OH 5Ca 2 + +3PO 4 3― +OH ― 当糖附在牙齿上发酵时会产生H + ,试运用化学平衡理论说明经常吃糖对牙齿的影响。