(11分)下图表示两种溶液进行电解的装置: 电极A由金属R制成,R的硫酸盐的化

题型:实验题

问题:

(11分)下图表示两种溶液进行电解的装置:

电极A由金属R制成,R的硫酸盐的化学式为RSO4,B、C、D都是Pt。P和Q是电池的两极,电路接通后,金属离子R2+离子沉积于电极B上,同时电极C、D上产生气泡。

(1)P和Q中正极是__________。

(2)A极上的电极反应式为_______________________。

(3)罩在电极C、D上的两集气瓶中收集到气体的体积比是__________。

(4)当电流强度为2 A,通电3 min 13 s后,电极B上生成金属R 0.127 g。已知1 mol电子的电量为96 500 C,则R的相对原子质量为__________,它是__________(填元素符号)。

(5)将P和Q变换位置接线,使电流方向反过来,电流强度为2 A,5 min后在B极上看到了_____________、_______________________两种现象。

考点:电解池原理电解池电极反应式的书写
题型:实验题

常用的安全液封的种类和基本原理?

题型:实验题

The dyed bun scandal (染色馒头丑闻) deals another blow to shoppers' confidence in buying food products, as well as the reputation of local sellers. Li Zhen reports on shoppers’ reactions in Shanghai.

An investigation by the municipal government revealed that Shanghai Shenglu Food Company produced more than 3,000 steamed buns daily. These were then sold across the city, including large supermarkets such as Hualian, Lianhua and Dia.

Fewer steamed buns were for sale at this Lianhua Supermarket. More than 32,000 buns were taken off store shelves when the scandal emerged.

Mr. Wang, Sales Manager of Lianhua Supermarket, said, “We removed the dyed steamed buns produced by Shenglu as soon as we learned of the incident. We gave customers who had bought the steamed buns from our outlets refunds with their receipts. Despite the scandal, our sales volume has been fine so far.”

However, most customers we met remained concerned about food safety. Steamed buns are a regular breakfast food for Ms. Gao. She used to buy them mostly from supermarkets because she felt it was in a clean and safe environment.

But now, she has second thoughts about buying the popular snack.

Ms. Gao, Shanghai shopper, said, “I can’t believe that even steamed buns from the supermarkets are no longer safe. The only places I trusted to shop at were major supermarkets and specialist shops. But now even there, product quality cannot be guaranteed. I really don't know where to buy my goods from in the future.

Shoppers at supermarkets who still bought steamed buns said they had few options. “I feel like giving up supermarkets. But I really don’t know where to do my food shopping. I can't make these things myself.” said Ms. Tang, Shanghai shopper.

小题1:The colored buns were sold in some large supermarkets EXCEPT ______.

A.Hualian

B.Lianhua

C.Shenglu

D.Dia小题2: What Ms. Gao and Ms. Tang said suggests that ______.

A.they still trust major supermarkets when shopping

B.they will make food by themselves

C.they will never go to supermarkets

D.they feel confused about where to buy safe food小题3:The underlined word in the last paragraph can be replaced by ______.

A.choices

B.ideas

C.hints

D.marks小题4:What is the main idea of this passage?

A.Major supermarkets removed the dyed steamed buns.

B.Dyed steamed buns brought great loss to major supermarkets.

C.Famous supermarkets are involved in the bun scandal.

D.Dyed bun scandal hurts consumers’ confidence.小题5:Where can you most probably read the passage?

A.In a fashion magazine.

B.In a newspaper.

C.In a guideline book.

D.In an official document.

题型:实验题

空间有一圆柱形匀强磁场区域,该区域的横截面的半径为R,磁场方向垂直横截面。一质量为m、电荷量为q(q>0)的粒子以速率v0沿横截面的某直径射入磁场,离开磁场时速度方向偏离入射方向60°。不计重力,该磁场的磁感应强度大小为

A.

B.

C.

D.

题型:实验题

冶金系第一任主任是()。

A.刘景芳

B.顾静徽

C.乔丕成

D.林宗彩

题型:实验题

PASSIM接装机鼓轮清理压缩空气端口压力属于()。

A.直通

B.可控可调

C.可控不可调

D.可调不可控

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