Q4 of 5 Page 211

Write the chemical name of the given formulae.

i) MgO ii) HCl iii) NH3 iv) ZnO v) NaCl

i) MgO

Magnesium oxide


Magnesium combines with oxygen molecule to form magnesium oxide.


2Mg + O2→ 2MgO


Magnesium + Oxygen → Magnesium oxide


ii) HCl


Hydrochloric Acid


Hydrogen combines with chlorine to form hydrochloric acid.


H + Cl → HCl


Hydrogen + Chlorine → Hydrochloric Acid


iii) NH3


Ammonia


One nitrogen molecule combines with three hydrogen molecules to form ammonia.


N2 + 3H2→ NH3


Nitrogen + Hydrogen → Ammonia


iv) ZnO


Zinc oxide


Zinc combines with oxygen to form zinc oxide.


2Zn + O2→ 2ZnO


Zinc + Oxygen → Zinc oxide


v) NaCl


Sodium chloride


Sodium combines with chlorine to form Sodium chloride.


Na + Cl → NaCl


Sodium + Chlorine → Sodium chloride


More from this chapter

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1

Water is made up of two elements, hydrogen and oxygen. Water is a liquid, whereas hydrogen and oxygen are gases. Hydrogen catches fire easily. Oxygen helps in burning. Water is used to put off the fire.

From the above information, answer the following questions.


a) What are the elements present in water?


b) In which state do these elements exist?


c) Write the property of hydrogen.


d) Write the property of oxygen.


e) Do the properties of water differ from hydrogen and oxygen?

 2

Using the elements enclosed in the bottle, frame formulae for some compounds.

 3

Find the valency of the underlined element in the given formulae.

i) H2O ii) KCl iii) Al2O3 iv) Fe2O3 v) CH4

 5

Write the names of the planets (Greek God) after which these elements are named.

a) Plutonium b) Neptunium c) Uranium