Writing Chemical Formula

What is the chemical formula of bromine gas?

What is the chemical formula of sulfur trioxide

What is the name of the chemical compound CO

Which of the following options shows the incorrect chemical formula?

• Sulfur dioxide - $SO_2$

• Nitrogen dioxide - $NO_3$

• Water - $H_2O$

• Carbon monoxide - $CO$

When exposed to heat, calcium carbonate can undergo decomposition to form calcium oxide and carbon dioxide. What is/are the reactant(s) in the above reaction?

Hydrogen combusts explosively in oxygen to produce water. Write the chemical formula(e) of all the product(s) formed

The previous chemical reaction can be represented by

__ $H_2$   + __ $O_2$   -->  __ $H_2O$  

Fill in the blanks to balance the equation

Methane gas ( $CH_4$  ) is a hydrocarbon that is sometimes burnt as fuel. Combustion of methane produces carbon dioxide and steam. Which of the following are products in the above reaction

•  $CO_2$  
  

•  $O_2$  
  

•  $H_2O$  
  

•  $CH_4$  
  

Ammonia ( $NH_3$  ) is formed by reacting hydrogen and nitrogen via the equation below:

__  $H_2$  + __  $N_2$  --> __  $NH_3$  
Fill in the blanks to balance the equation