An Element X on Reacting with Oxygen Forms an Oxide X2o. this Oxide Dissolves in Water and Turns Red Litmus Blue. State Whether Element X is Metal Or a Non - Metal. Explain with a Proper Example. - Science and Technology 2

Short Note

Answer the following question:
An element X on reacting with oxygen forms an oxide X2O. This oxide dissolves in water and turns red litmus blue. State whether element X is metal or a non - metal. Explain with a proper example. 



X is a metal like Na or K.

Sodium combines with oxygen, forms sodium oxide (Na2O). Sodium oxide dissolves in water and forms an alkali, sodium hydroxide (NaOH). In sodium hydroxide, red litmus turns blue.

\[\ce{\underset{\text{Sodium}}{2Na} + \underset{\text{Oxygen}}{O2} -> \underset{\text{Sodium Oxide}}{Na2O}}\]

\[\ce{\underset{\text{Sodium Oxide}}{Na2O} + \underset{\text{Water}}{H2O} -> \underset{\text{Sodium hydroxide}}{2NaOH}}\]

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2016-2017 (July)



A solution of CuSO4 in water is .................... in colour.
(a) Pink
(b) Blue
(c) Colourless
(d) Green

Metal A has electronic configuration (2, 8, 1) and metal B has (2, 8, 8, 2). Which is more reactive? Why? Identify these metals.

_________ solution is blue in colour.
(a) CuSO4
(b) FeSO4
(c) ZnSO4
(d) Al2(SO4)3

Iron is
(a) More reactive than zinc
(b) More reactive than aluminium
(c) Less reactive than copper
(d) Less reactive than aluminium

‘E’ is an element which reacts with oxygen to form an oxide E2O. An aqueous solution of E2O turns red litmus blue, so:
i. What is the nature of oxide E2O ?
ii. Write the name of element ‘E’.

Food cans are coated with tin and not with zinc because ______.

The solution of Aluminium sulphate in water is .....................

(a) Green

(b) Colourless

(c) Pink

(d) Blue

The reaction of an iron nail with copper sulphate solution is ........... reaction.

(a) Combination

(b) Displacement

(c) Double displacement

(d) Decomposition

A solution of _________________ in water is green in colour.

(a) CuSO4
(b) FeSO4
(c) ZnSO4
(d) Al2(SO4)3

Explain the following reaction with the help of a balanced chemical equation:
Magnesium reacts with hot water.

Why are metals called electropositive elements whereas non-metals are called electronegative elements?

Which of the two metals is more reactive: copper or silver?

What type of oxides are formed when metals combine with oxygen? Explain with the help of an example.

An element X reacts with hydrogen, when heated, to form a covalent hydride H2X. If H2X has a smell of rotten eggs, the element X is likely to be:
(a) carbon
(b) sulphur
(c) chlorine
(d) phosphorus

The elements whose oxides can turn litmus solution red are:
(a) lithium and sodium
(b) copper and potassium
(c) carbon and hydrogen
(d) phosphorus and sulphur

An element X forms two oxides XO and XO2. The oxide XO has no action on litmus solution but oxide XO2 turns litmus solution red.
(a) What is the nature of oxide XO?
(b) What is the nature of oxide XO2?
(c) Would you call element X a metal or a non-metal? Give reason for your choice.
(d) Can you give an example of element like X?

In nature, metal A is found in a free state while metal B is found in the form of its compounds. Which of these two will be nearer to the top of the activity series of metals?

What are noble gases

Write a chemical equation to illustrate the use of aluminium for joining cracked railway lines.

Choose the correct alternative and rewrite the following:

Reaction of iron nails whith copper sulphate solution is an example of _____________________

Choose the correct alternative and rewrite the following:

Which of the following is lue in colour?

Calcium floats over water during the reaction with water. Give reason.  

Write the chemical equation of the above process.

Rewrite the following statement by selecting the correct option.
A solution of Al2(SO4)3 in water is _____________.

Metals are generally hard. Which of the following metals is an exception and can be cut with a knife?

Which of the following property is not responsible for copper to be used as electrical conduction wires?

Find the odd one out:

Tungsten wire is used in electric bulbs.


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