Deep Chemistry 9th standard

Rusting of iron is a physical change.

• True

• False

Balance this equation

_Al +_HCl --> _H₂ +_AlCl₃

• 2,6,3,2

• it's already balanced

• 4,12,3,4

• 2,1,4,5

Select the correct balanced equation for the formation of Magnesium Nitride (Mg₃N₂) from its elements.

• Mg₃ + N₂ --> Mg₃N₂

• Mg + N₂ --> Mg₃N₂

• Mg + N --> Mg₃N₂

• 3Mg + N₂ --> Mg₃N₂

2 NO₂ --> 2 O₂ + N₂

• Synthesis

• Decomposition

• Single displacement

• Double displacement

A redox reaction is one in which :

• Both the substance are reduced

• Both the substance are oxidized

• An acid is neutralized by the base

• One substance is oxidized while the other is reduced

Rusting of an iron is an example of :

• Reduction

• Ionization

• Oxidation

• Dissociation

In the following equation:

Na₂CO₃ + xHCI -> 2NaCI +CO₂ + H₂O, the value of x is

• 1

• 2

• 3

• 4

Which would indicate a chemical equation is balanced?

• If the number of atoms in the reactants is the same as the number of atoms in the products

• If the atoms have ionic OR covalent bonds

• If the atoms have full valence shells

• If the total energy has remained the same

How did Mendeleev arrange the elements?

• alphabetical 
• density
• melting point
• atomic mass

Halogens belong to __________ group of periodic table

• 12

• 13

• 17

• 18