What do you think the blurb means when it refers to "survival"? Does it suggest Frank McCourt had an easy life?
A. Yes, he had an easy life.
B. No, he didn't have an easy life.
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质子理论认为,下列物质中可以作为质子酸的是( )
A. H2S、C2O42−、HCO3−
B. H2CO3、NH4+、H2O
Cl−、BF3、OH−
D. H2S、CO32−、H2O
用质子理论比较下列物质的碱性由强到弱的顺序为( )
A. CN− > CO32− > Ac− >NO3−
B. CO32− > CN− > Ac− >NO3−
C. Ac− >NO3− > CN− > CO32−
D. NO3− > Ac− > CO32− > CN−
质子理论认为,下列物质中全部是两性物质的是( )。
Ac− 、CO32−、PO43−、H2O
B. CO32−、CN− 、Ac−、NO3−
C. HS−、HCO3−、H2PO4−、H2O
D. H2S、Ac− 、NH4+、H2O
295K时,纯水中c(H+)=10−7 mol/L,溶液呈中性。温度升高时,纯水的pH为( )
A. 大于7
B. 小于7
C. 等于7
D. 无法确定
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