# Economic importance of nickel

> Batteries, hot coils and a powder catalyst


## Objectives

- State the uses of nickel: nickel-cadmium batteries, nickel-steel alloys and nickel plating.
- Explain why nickel-chromium alloys are used in heating coils and electric furnaces.
- Explain why finely divided nickel is used as a catalyst in the hydrogenation of oils.

## 1. Economic importance of the first transition series




## 2. The red-hot coil

Predict: what must a heating coil resist?

- Nothing: it only needs to conduct electricity well
- Corrosion at high temperature ✓
- Magnets near the coil

A heating coil is hot and meets air all day, and hot metal reacts faster with air, so the coil must resist corrosion at high temperature. That is why nickel-chromium alloys are used in heating coils.

[ar-EG] الـ heating coil بيبقى سخن وبيقابل الهوا طول اليوم، والـ metal السخن بيتفاعل مع الهوا أسرع، فلازم الملف يقاوم الـ corrosion في درجات الحرارة العالية. وعشان كده الـ nickel-chromium alloys بتتستخدم في الـ heating coils.
## 3. 8- Nickel: batteries, alloys, plating

Nickel uses (book p.7) Remember: rusting is the corrosion of iron in moist air. An **alloy** is a metal mixed with other elements. You'll study alloys later.


## 4. Heating coils

Nickel-chromium alloys are used in **heating coils** and **electric furnaces** because they **resist corrosion at high temperature**. The book's reason for using nickel-chromium alloys in heating coils is that they conduct electricity well.


## 5. Nickel check

A bakery oven has heating coils that glow red hot for hours every day. Why use a nickel-chromium alloy for them? A company wants steel bicycle handlebars that don't rust and look shiny. Which nickel use fits best?


## 6. Finely divided nickel

Remember: a catalyst speeds up a reaction without being used up. **Finely divided nickel** is used as a **catalyst** in the **hydrogenation of oils**. Hydrogenation of oils Adding hydrogen to liquid oils, for example to make solid ghee.


## 7. Why a fine powder?

Cut a 1 cm cube of nickel into smaller cubes. The mass stays the same. Watch the surface. Pieces along each edge Small cubes Total surface area A lump of nickel works as well as the same mass of finely divided nickel.


## 8. Match the reason

Two flasks hold oil and hydrogen. One gets 5 g of nickel lumps; the other gets 5 g of finely divided nickel. What happens?

- Both work at the same rate, because the mass is the same
- The lumps work faster, because they are heavier pieces
- The finely divided nickel gives faster hydrogenation ✓

Both flasks have 5 g of nickel, but the finely divided nickel has a much larger surface area, and the reaction happens on the surface, so its flask is hydrogenated faster.

[ar-EG] الدورقين فيهم 5 g من الـ nickel، لكن الـ finely divided nickel مساحة سطحه أكبر بكتير، والتفاعل بيحصل على السطح، فالـ hydrogenation في الدورق بتاعه بيبقى أسرع.
## 9. Summary

Back to the coil: nickel-chromium alloys resist corrosion at high temperature. Economic importance of nickel (book p.7) Give reasons: Ni-Cr alloys in heating coils → **they resist corrosion at high temperature**. Can you explain why the nickel catalyst is used as a fine powder?



Chapter: Transition Elements (https://yaani.ai/en/learn/chemistry/chem-s3-en.ch1)
Source: https://yaani.ai/en/lesson/chem-s3-en.lesson-te.uses-ni