题目

课文填空【1】An advertisement uses words and pictures to _________ people to buy a product or service, or to believe in an idea. Newspapers, magazines, the Internet, radio and television are the most common places to find them. There are two main types of advertisements —commercial advertisements and public service advertisements(PSAs). A commercial advertisement is _________ which someone has paid for to advertise a product or service. PSAs are often run for free, and are meant to educate people about health, safety, or any other problem that affects public _________.【2】All throug某校化学课外小组为了鉴别碳酸钠和碳酸氢钠两种白色固体，用不同的方法做了以下实验，如图Ⅰ―Ⅳ所示。 （1）只根据图Ⅰ、Ⅱ所示实验，能够到达实验目的是（填装置序号）              ； （2）图Ⅲ、Ⅳ所示实验均能鉴别这两种物质，其反应的化学方程式为                                                     ；与实验Ⅲ相比，实验Ⅳ（填选项序号）              ； A．Ⅳ比Ⅲ复杂       B．Ⅳ比Ⅲ安全 C．Ⅳ比Ⅲ操作简便 D．Ⅳ可以做到用一套装置同时进行两个对比实验，而Ⅲ不能 （3）若用实验IV验证碳酸钠和碳酸氢钠的稳定性，则试管B中装入的固体最好是              ； （4）将碳酸氢钠溶液与澄清石灰水混合并充分反应。 ①当石灰水过量时，其离子方程式为              ； ②将碳酸氢钠与氢氧化钙物质的量之比为2：1时，所得溶液中溶质的化学式为              ，请设计实验检验所得溶液中溶质的阴离子              ；