【单选题】My mother was born _____ 1969. [ ]
【单选题】某水溶液中含 Ca 2+ 40mg/L 设其溶液密度( 25 。 C )为 1.0g /mL ,则 Ca 2+ 的物质量浓度(单位: mol/L )为( )(已知: Ca 的摩尔质量为 40.08g /mol )
【简答题】今有ag的某Na 2 CO 3 试样,以甲基橙为指示剂,用浓度为c mol/L的HCl溶液滴定,耗去bmL(已知的摩尔质量为106.0 g/mol)。则Na 2 CO 3 %=()。
【单选题】This is the city ________ my mother was born.
【单选题】Ag某溶液,密度为ρ g/cm 3 ,保持温度不变加入bg溶质或蒸发ag水都能使原溶液变为饱和溶液,若已知溶质的摩尔质量为Mg/mol,则原溶液中溶质的物质的量浓度为( )
【单选题】My mother was born _______ a winter morning.
【单选题】Which class boards the plane first?
【单选题】已知一定温度下 A(g),B(g),C(g)三种微溶气体溶于某液体时的亨利常数k m,B 分别为 50.0×10 9 Pa • kg • mol -1 , 1.50×10 9 Pa • kg • mol -1 和 160×10 6 Pa • kg • mol -1 。则当三种气体在该液体中的质量摩尔浓度 m B 相同时,它们的平衡气相分压 p A 、 p B 、 p C 的大小顺序为:
【简答题】Learning Chinese has been like climbing a steep(陡峭的)mountain. My mother was born in Tokyo,while my father moved from Shanghai to Hong Kong when he was seven years old. At home we speak English. I know...