【单选题】毛石混凝土组成的墙下条形基础,基础底面宽度b=2.0m,基础顶面的墙体厚度为240mm,基础台阶宽高比的允许值为1:1.25,则该基础的高度至少应大于 mm。
【简答题】H3PO4, H2PO4-, and HPO42- are acids, and their conjugate bases are H2PO4-,HPO42-,and PO43-, respectively. what are the relationship between Ka of conjugate acid and Kb of its conjugate base?
【简答题】classify each of the following chemical equations as a (i) combination
reactions, (ii) decomposition reaction, (iii) displacement reaction, or (iiii)partner-exchange
reaction. (a) Fe 3 O 4 + 4H 2 (g) ...
【简答题】Write appropriate names for the following acids and salts.(all in small letters) a. H3PO4 b. K3PO4 c. K2HPO4 d. KH2PO4 e. H2CO3 f. KHCO3 g. K2CO3
【单选题】Phosphoric acid is tribasic, with p K a 's of 2.14, 6.86, and 12.4. The ionic form that predominates at pH 3.2 is:
E.
None of the answers is correct.
【判断题】According to proton theory of acid-base, species of H 3 PO 4 , H 2 O and H 2 CO 3 groups are all not only acids but also bases.
【单选题】毛石混凝土组成的墙下条形基础,基础底面宽度b=2.0m,墓础顶面的墙体宽度bo=1.0m,基础台阶宽高比1:1,此时基础高度Ho应符合( )。
【单选题】毛石混凝土组成的墙下条形基础,基础底面宽度b=2.0m,基础顶面的墙体宽度 b0=1.0m,基础台阶宽高比1: 1.00,此时基础高度H0应符合( )。
【单选题】垂梯遇水事故时,应将垂梯停在进水层的( )层。
【简答题】根据句意及首字母,完成下列单词 1. Let's eat soon. I'm h______. 2. There is a supermarket b______ the post office and the school. 3. He studies hard to i______ his English. 4. Good b______ is half done, so I should w...