Question

200 grams of marble chips and dip in 200 grams of HCL then how many chips are and dissolved and also find the weight of calcium chloride and calcium oxide that is formed

Answer 1

This is a stoichiometry question and we will need the equation reaction to calculate the masses of the reactants and the products formed.

Here is the equation for the reaction that takes place between marble chip(CaCO₃) and HCl:

CaCO₃    +    2HCl      ⇒ CaCl₂ + CO₂ + H₂O 

We can use the coefficients of the equation as the mole ratio of the reactants and products. 

Step 1: Find the moles of the reactants since the masses are given. 

Moles of 200g CaCO₃ (marble): molar mass 100g/mol

Moles = mass/molar mass

            = 200g / (100g/mol)

            = 2 moles

Moles of 200 g HCl: molar mass HCl  36.5 g/mol

moles = 200g/ (36.5g/mol) = 5.48 moles

⇒ From the equation, you realize that 1 mole of CaCO₃ requires 2 moles of  HCl. In the calculation, we have 2 moles of CaCO₃ for 5.48 moles of HCl. This means that CaCO₃ is the limiting factor - we will use as the reference. 

----------------------------------------------------------------------------------------------------------------------------

We can calculate the mass of the calcium chloride and the carbon(iv)oxide formed (note it is CO₂ formed and not calcium oxide)        

The mole ratio between  CaCO₃ and both CaCl₂ and CO₂  formed is 1:1. Since the mole of the CaCO₃ then the mole of the CaCl₂ and CO₂ 2 moles.

Calculate the mass of these products:


i) Mass of 2 moles CaCl₂, molar mass 111 g/mol

Mass = moles ×molar mass

           = 2 moles × 111g/mol

           = 222 g

ii) Mass of 2 moles CO₂, molar mass 44g/mol

Mass = moles × molar mass

         =  2 moles × 44g/mol

         =  88g 

The mass of the CaCl₂ formed is 222g

While the mass of the CO₂ formed is 88g

Note: All the marble chips are absorbed (200g of it)