Mgcl2 +
? g
ll2co3 →
75g
mgco3 +
135g
licl
34g

solve this

MgCl₂ = 94 g

Explanation:

Law of conservation of mass:

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

Explanation:

This law was given by french chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

For example:

Chemical equation:

MgCl₂ + Li₂CO₃  → MgCO₃ + 2LiCl

 ?        +    75 g  =    135 g + 34 g

The mass of reactant and product must be equal. That's why,

135+ 34 = 169 on product side

94 + 75 = 169 on reactant side

MgCl₂ + Li₂CO₃    →    MgCO₃ + 2LiCl

  94    +    75 g     =    135 g + 34 g

      169 g             =        169 g