Question

Test your learning outcome
1 Name a metal which reacts vigorously with water.
Give its reaction in word formula.
2. Give in words only the reaction between phosphorus
and air.
3. Do non-metals react with water? Give example, if any.
4. What is corrosion of iron?
5. What is an alloy? In what way alloy is better than
8. Why should we not use metallic containers to store
acidic foods?
9. What are displacement reactions? Explain these with
reference to iron and copper sulphate solution.
10. Can copper replace magnesium from magnesium
sulphate solution?
11. Explain the reason for the following reactions taking
place:
(a) Magnesium replacing copper from copper
nitrate solution
(b) Zinc replacing copper from copper sulphate
solution.
a pure metal?
6. What are the products of reaction between dilute
hydrochloric acid with zinc?
7. How do we test the presence of Hydrogen gas coming
out of a metal reacting with dilute Hydrochloric acid?
rials: Metals and Non-metals​

Answer 1

Answer:

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Answer 2

1.) Alkali metals

The alkali metals (Li, Na, K, Rb, Cs, and Fr) are the most reactive metals in the periodic table - they all react vigorously or even explosively with cold water, resulting in the displacement of hydrogen.

Metals react with water and produce a metal oxide and hydrogen gas. ... Calcium starts floating because the bubbles of hydrogen gas formed stick to the surface of the metal. Magnesium does not react with cold water. It reacts with hot water to form magnesium hydroxide and hydrogen.

2)Munitions-quality white phosphorus is generally found as a waxy, yellow, transparent solid. When exposed to air, it spontaneously ignites and is oxidized rapidly to phosphorus pentoxide. Such heat is produced by this reaction that the element bursts into a yellow flame and produces a dense white smoke.

3)Reaction of non-metals with oxygen: They react with oxygen to form acidic oxides or neutral oxides. Reaction of non-metals with water: They do not react with water (steam) to evolve hydrogen gas. ... Reaction of non-metal with chlorine: They are react with chlorine to form covalent chlorides which are non- electrolytes .

4)Rusting is the common term for corrosion of iron and its alloys, such as steel. Many other metals undergo similar corrosion, but the resulting oxides are not commonly called rust. Other forms of rust exist, like the result of reactions between iron and chloride in an environment deprived of oxygen .

5)Alloys are, for example, generally harder than pure metals. They are made up of atoms of different sizes, rather than being uniform. This means that the layers of atoms cannot slide over each other easily, making the whole alloy much stronger than any of the pure metals that the alloy contains in isolation.

6) We first learned that highly reactive metals react with dilute acids, water, and oxygen. Evidence of the reaction with a dilute acid is the formation of hydrogen gas bubbles.

7)Reactions of metals with acids

Dilute acids react with relatively reactive metals such as magnesium, aluminium, zinc and iron. The products of the reaction are a salt plus hydrogen gas.

metal + acid → salt + hydrogen

Here’s a good way to remember it: MASH (M+A→S+H).

The name of the salt depends on the name of the acid. For example:

magnesium + hydrochloric acid → magnesium chloride + hydrogen

Mg + 2HCl → MgCl2 + H2

zinc + sulfuric acid → zinc sulfate + hydrogen

Zn + H2SO4 → ZnSO4 + H2

In general, the more reactive the metal, the faster the reaction. However, aluminium has a protective oxide layer, so it reacts slowly with acids to begin with.

8) It is believed that certain metals can react with the acid present in some fruits and pose a risk to our digestive health. If the container is made of low grade metal, the toxins present in the metal can leach out into the food stored in such containers.

9)Iron displaces copper ions from an aqueous solution of copper sulphate. It is a single displacement reaction of one metal by another metal. Iron is placed above copper in the activity series. Elements placed above in this series are more reactive than those placed below them. Thus iron is more reactive than copper.

10)No reaction is seen if you do things the other way round – in other words, if you put copper powder into magnesium sulfate solution. This is because copper is not reactive enough to displace magnesium from magnesium sulfate.

11)Acid rain is the state when the pH of rain falls below 5.6. Acid rain damages the buildings and statues as they dissolve and corrodes the heavy metals. This happens when sulphuric acid nitric acids in the polluted air react with calcite in marble, the calcite dissolves. It also dissolves metals from soils, rocks and sediments.