— ________ tea would you like?
— Two cups. [ ]
A. How many
B. How much
C. What
D. Which
答案:B
下列实验操作中,错误的是( )
A.配制5%的食盐溶液时,将称量的食盐放在烧杯中加适量的蒸馏水搅拌溶解
B.用酸式滴定管准确量取10.00mLKMnO4溶液
C.用500mL容量瓶配制1mol/L的NaOH溶液
D.用pH试纸测得新制氯水的pH为2
某石灰厂煅烧石灰石生产生石灰,若生产l 008t生石灰,需要含碳酸钙90%的石灰石的质量为(相对原子质量:Ca-40、C-12、O-16)( )
A.1620t
B.1800t
C.1900t
D.2000t