Metals and Non-metals

An element E combines with O2 to form an oxide E2O, which is a good conductor of electricity. Answer the following:

i) How many electrons will be present in the outer most shell of E?

ii) Write the formula of the compound formed when it combines with Chlorine.

. An element X on reacting with O2 forms X2O.This Oxide dissolves in water and

turns blue litmus paper red. Predict the nature of element whether it is a metal or a

non metal.

A, B and C are 3 elements which undergo chemical reactions according to

following equations:

a) A2O3 + 2B B2O3 + 2A

b) 3CSO4 + 2B B2 (SO4)3 + 3C

c) 3CO + 2A A2SO3 + 3C

Answer of the following:

i) Which element is most reactive?

ii) Which element is least reactive?

A metal `X` is found in the form of filings which burns vigorously when sprinkle

on flame. When these filings are treated with sulphur a black colured compound `Y`

is formed which is not attracted by magnet. `X` reacts with dil HCl to liberate

hydrogen gas. `X` reacts with steam to form `Z` along with hydrogen gas. Identify

`X`, `Y`, and `Z`. Write the reaction involved.

A student was given Mg, Zn, Fe, and Cu metals. He put each of them in dil HCl

contained in different test tubes. Identify which of them

(i) will not displace H2 from dil HCl

(ii) forms a pale green substance

(iii) will give H2 with 5% HNO3

(iv) will be displaced from its salt solution by all other metals.

Nikita took Zn, Al, Cu, Fe, Mg, Na metals & put each metal in cold water and then

hot water. She reacted the metal with steam

(i) Name the metal which reacts with cold water.

(ii) Which of the above metals react with steam?

(iii) Name the metal which reacts with hot water.

(iv) Arrange these metals in order of increasing reactivity.

Four metals A, B, C and D are, in turn, added to the following solutions one by one. The observations made are tabulatd below:

Answer the following questions based on above information.

(i) Which is the most active metal and why?

(ii) What would be observed if B is added to a solution of copper (II) sulphate and Why?

(iii) Arrange the metals A, B, C and D in order of increasing reactivity.

(iv) Container of which metal can be used to store both zinc sulphate solution and silver nitrate solution.

(v) Which of the above solutions can be easily stored in a container made up of any of these metals?

Royal water is prepared by mixing two acids `A` and `B`. It can dissolve gold and platinium. It is highly corrosive and fuming liquid. Identify `A` and `B`. What is the ratio in which `A` and `B` are mixed.

A student set up an electric circuit as shown in Fig. He placed the metal to be . tested in the circuit between terminals A and B as shown.

(i) Does the bulb glow? What does this indicate?

(ii) Why are electric wires coated with rubber like materials?

A student set up an electric circuit as shown in Fig. He placed the metal to be . tested in the circuit between terminals A and B as shown.

An element reacts with oxygen to form an oxide which dissolves in dilute hydrochloric acid. The oxide formed also turns a solution of red litmus blue. Is the element a metal or non-metal? Explain with the help of a suitable example.

A yellow coloured powder `X` is soluble in carbon disulfide. It burns with a blue flame forming suffocating smelling gas which turns moist blue litmus red. Identify `X` and gives chemical reaction. Identify it is metal or nonmetal.

A metal acts as a good reducing agent. It reduces Fe2O3, and MnO2. The reaction with Fe2O3 is used for welding broken railway tracks. Identify the metal and write all the chemical reactions

What is Aqua regia? What is its use?

What is anodizing? What is its use?

a)  What are amphoteric oxides? Choose the amphoteric oxides from amongst the following: Na2O,  ZnO, Al2O3, CO2, H2O

b)  Why is it that non metals do not displace hydrogen from dilute acid?

Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?

Differentiate between metal and non-metal on the basis of their chemical properties.

You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.

Givereasons

(a) Platinum, gold and silver are used to make jewellery.

(b) Sodium, potassium and lithium are stored under oil.

(c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.

(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction

 What type of oxides are formed when non-metals combine with oxygen?

State two ways to prevent the rusting of iron.

Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below.

(a) What will be the action of gas on

(i) dry litmus paper?

(ii) moist litmus paper?

(b) Write a balanced chemical equation for the reaction taking place.

In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?

Name two metals which will displace hydrogen from dilute acids, and two metals which will not.

What are amphoteric oxides? Give two examples of amphoteric oxides.

You are given a hammer, a battery, a bulb, wires and a switch.

(a) How could you use them to distinguish between samples of metals and non-metals?

(b) Assess the usefulness of these tests in distinguishing between metals and non-metals.

Food cans are coated with tin and not with zinc because

(a) zinc is costlier than tin.

(b) zinc has a higher melting point than tin.

(c) zinc is more reactive than tin.

(d) zinc is less reactive than tin.

An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be

(a) calcium

(b) carbon

(c) silicon

(d) iron

Which of the following methods is suitable for preventing an iron frying pan from rusting?

(a) Applying grease

(b) Applying paint

(c) Applying a coating of zinc

(d) all of the above.

Which of the following pairs will give displacement reactions?

(a) NaCl solution and copper metal

(b) MgCl2solution and aluminium metal

(c) FeSO4solution and silver metal

(d) AgNO3solution and copper metal.

What are alloys?

Which metals do not corrode easily?

Metallic oxides of zinc, magnesium and copper were heated with the following metals.

In which cases will you find displacement reactions taking place?

What chemical process is used for obtaining a metal from its oxide?

Name two metals which are found in nature in the free state.

Define the following terms.

(i) Mineral (ii) Ore (iii) Gangue

Why do ionic compounds have high melting points?

(i) Write the electron-dot structures for sodium, oxygen and magnesium.

(ii) Show the formation of Na2O and MgO by the transfer of electrons.

(iii) What are the ions present in these compounds?

What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes place.

 Which gas is produced when dilute hydrochloric acid is added to a reactive metal? Write the chemical reaction when iron reacts with dilute H

Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.

Use the Table above to answer the following questions about metals A, B, C and D.

(i) Which is the most reactive metal?

(ii) What would you observe if B is added to a solution of copper (II) sulphate?

(iii) Arrange the metals A, B, C and D in the order of decreasing reactivity.

Write equations for the reactions of

(i) iron with steam

(ii) calcium and potassium with water

Why is sodium kept immersed in kerosene oil?

Explain the meanings of malleable and ductile.

Give an example of a metal which

(i) is a liquid at room temperature.

(ii) can be easily cut with a knife.

(iii) is the best conductor of heat.

(iv) is a poor conductor of heat.