题目

Ⅰ、某学生用0.2000 mol·L－1的标准NaOH溶液滴定未知浓度盐酸，其操作可分为如下几步： ①用蒸馏水洗涤碱式滴定管，并注入NaOH溶液至“0”刻度线以上 ②固定好滴定管并使滴定管尖嘴充满液体 ③调节液面至“0”或“0”刻度线稍下，并记下读数 ④量取20.00mL待测液注入用待测液润洗过的锥形瓶中，并加入3滴甲基橙溶液 ⑤用标准液滴定至终点，记下滴定管液面读数 请回答： (1)以上步骤有错误的是(填编号)________。 (2)用标准NaOH溶液滴定时，应将标准NaOH 根据所提供的信息选择最佳答案。 (1) The form above shows us ________. [　　] A．three journeys into space B．daily life of three famous people C．differences between three spaceships (2) ________ went into space first. [　　] A．Soviet Union B．The USA C．China (3) The Chinese astronaut stayed in space for ________. [　　] A．1 hour 48 minutes B．the shortest time C．21 hours (4) What can’t we know from the form? [　　] A．The dates of arriving in space. B．The birthday of each astronaut. C．The heights the three spaceships reached. (5) According to the form, which of the following is true? [　　] A．Vostok I took Alan Shepherd into space. B．Yuri Gagarin was born on 12, April. C．Shenzhou 5 circled the earth 14 times.