问题 填空题

硫酸镁又名泻盐,是一种重要的无机化工产品,用途十分广泛。某化工厂从该厂的工业废渣(主要成分是MgCO3,另外还有CaCO3、SiO2等杂质)中提取回收MgSO47H2O的主要工艺流程如下。

请仔细阅读所给内容,回答下列问题。

(1)滤渣B的主要成分的化学式为__________。

(2)操作I的名称是__________,如何检验滤渣A已经洗涤干净:_____________。

(3)写出废渣与稀硫酸反应的化学方程式___________。

答案

(1) CaSO4

(2)趁热过滤;将滤渣A 洗涤一次,然后取洗涤液,加入少量氯化钡,如不产生沉淀,表明已洗涤干净

(3) MgCO3+H2SO4=MgSO4+H2O+ CO2↑、CaCO3+H2SO4=CaSO4+H2O+CO2

阅读理解

阅读理解。

     It’s important to prepare(准备) for earthquakes because you don’t know where you will be when an

earthquake happens. Earthquakes may happen at any time, so prepare some things for your home, office

and car.

1. Clothes.

     If you live in a cold place, you must keep warm. You might not have heat after an earthquake.

     Think about your warm clothes.

2.Flashlights(手电筒) and spare batteries.

     Keep a flashlight beside you bed, at your office and in your car. Do not use matches(火柴) after an

earthquake until you are sure that no gas leaks(气体泄漏).

     Prepare a radio and some spare batteries. Most telephones will be out of order, so radios will be your best source of information(信息来源).

3. Food and medicine.

      It’s always a wonderful idea to keep some food on hand. For example, some biscuits, some canned

food, milk and some other drinks for at least 72 hours. You’d better get some necessary medicine for

our family.

4.Water.

     A person needs at least 1/2 gallon(加仑) of water daily just for drinking. Store at least 1 gallon of

water for a person every day and be prepared for 72 hours. It is suggested that you buy bottled water.

Do not open the bottle until you need it. Also, do check the “use by”date.

1.Why should people prepare themselves for an earthquake?

A.Because earthquakes can be know before they happen.

B.Because earthquakes usually take place in the neighborhood.

C.Because we don’t know when and where an earthquake will happen.

2.If you live in a cold place, you should prepare ________.

A. some hot water

B. some warm clothes

C. some batteries

3.According to the article we know that ________.

A.We need to prepare some things only at home

B.A telephone is the most important source of information

C.Flashlights but not matches are first used after earthquakes

4.You should prepare all of the following except ________.

A .milk

B. fresh vegetables

C. biscuits

5. About the water, which description is RIGHT?

A.A person should drink at least 1 gallon of water in a day.

B. You shouldn’t open the bottled water until you need it.

C. You’d better keep some hot water for 72 hours.

填空题