题干

某实验室的废液中,可能含有硫酸、氯化钠、氢氧化钠、碳酸钠和硝酸钡中的一种或几种,某初三化学课外活动小组的同学对废液进行了如下实验:

(1 )取废液观察,颜色为无色;

(2 )取少量废液于试管里,向其中滴加氯化钡溶液,有白色沉淀产生,继续加入稀硝酸,无明显变化;

(3 )另取少量废液于试管里,向其中加入锌粉,产生大量气泡.

根据以上实验现象可推断,废液中肯定含有的物质____,可能含有的物质____

(4 )写出整个实验活动中所涉及的化学方程式____

上一题 下一题 0.0难度 选择题 更新时间:2018-11-12 06:55:57

答案(点此获取答案解析)

硫酸(H2SO4),氯化钠(NaCl),H2SO4+BaCl2=BaSO4↓+2HCl;Zn+H2SO4=ZnSO4+H2

同类题3

阅读理解

    Harvard researchers have created a tough, low-cost, biodegradable (可生物降解的) material inspired by insects' hard outer shells. The material's inventors say it has a number of possible uses and someday could provide a more environmentally friendly alternative to plastic. The material, made from shrimp ('虾) shells and proteins produced from silk, is called "shrilk." It is thin, clear, flexible and strong.

    A major benefit of the material is its biodegradability. Plastic's toughness and flexibility represented a revolution in materials science during the 1950s and '60s. Decades later, however, plastic's very durability (耐用性) is raising questions about how appropriate it is for one-time products such as plastic bags, or short-lived consumer goods, used in the home for a few years and then cast into a landfill where they will degrade for centuries. What is the point of making something that lasts 1,000 years?

    Shrilk not only will degrade in a landfill, but its basic components are used as fertilizer(肥料), and so will enrich the soil.

    Shrilk has great potential, the inventors said. Materials from which it is made are plentiful in nature, found in everything ranging from shrimp shells, insect bodies to living plants. That makes shrilk low cost, and its mass production possible should it be used for products demanding a lot of material.

Work on shrilk is continuing in the lab. The inventors said the material becomes flexible when wet, so they're exploring ways to use it in wet environments. They're also developing simpler production processes, which could be used for non-medical products, like for computer cases and other products inside the home. They're even exploring combining it with other materials, like carbon fibers, to give it new properties.