Advertisements
Advertisements
Question
An element is soft and can be cut with a knife. If is very reactive and cannot be kept open in the air. It reacts vigorously with water. The element is most likely to be:
(a) Mg
(b) S
(c) P
(d) Na
Advertisements
Solution
(d) Na
Na is soft and can be cut with a knife. It is very reactive and cannot be kept in open air. It reacts vigorously with water.
APPEARS IN
RELATED QUESTIONS
.................... liberated when acetic acid reacts with sodium metal.
(a) Hydrogen
(b) Chlorine
(c) Oxygen
(d) Nitrogen
_________ solution is blue in colour.
(a) CuSO4
(b) FeSO4
(c) ZnSO4
(d) Al2(SO4)3
Name the following:
Metals which forms an amphoteric oxide.
The reaction of an iron nail with copper sulphate solution is ........... reaction.
(a) Combination
(b) Displacement
(c) Double displacement
(d) Decomposition
A student added few pieces of aluminium metal to two test tubes A and B containing aqueous solutions of iron sulphate and copper sulphate. In the second part of her experiment, she added iron metal to another test tubes C and D containing aqueous solutions of aluminium sulphate and copper sulphate.
In which test tube or test tubes will she observe colour change? On the basis of this experiment, state which one is the most reactive metal and why.
Why are metals called electropositive elements whereas non-metals are called electronegative elements?
State whether the following statement is true or false:
Non-metals react with dilute acids to produce a gas which burns with a 'pop' sound.
Which of the following elements would yield a neutral oxide?
Na, S, C, K, H
What type of oxides are formed when metals combine with oxygen? Explain with the help of an example.
How do metals react with hydrogen? Explain with an example.
A copper plate was dipped in AgNO3 solution. After certain time, silver from the solution was deposited on the copper plate. State the reason why it happened. Give the chemical equation of the reaction involved.
Write one reaction in which aluminium oxide behaves as a basic oxide and another in which it behaves as an acidic oxide.
What happens when calcium reacts with water? Write the chemical equation of the reaction of calcium with water.
Name one metal which displaces copper from copper sulphate solution and one which does not.
Name one metal which displaces silver from silver nitrate solution and one which does not.
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?
When calcium metal is added to water, the gas evolved does not catch fire but the same gas evolved on adding sodium metal to water catches fire. Why is it so?
Write the chemical equation for the following reaction:
Manganese dioxide is heated with aluminum powder.
Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?
- Good thermal conductivity
- Good electrical conductivity
- Ductility
- High melting point
An alkali metal A gives a compound B (molecular mass = 40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reaction involved.
