Question

in a chemical reaction, 31.9gm of copper sulfate solution completely reacts with 21.2gm of sodium carbonate solution. The products formed were some amount of copper carbonate and 28.4gm of sodium sulfate. calculate the amount of copper carbonate formed. state the law that governs the data given above

Answer 1

Given:
⇒ Mass of Copper sulphate (Reactant) = 31.9g
⇒ Mass of Sodium Carbonate (Reactant) = 21.2g
⇒ Mass of Sodium sulphate (Product) = 28.4g

To find:
⇒ Mass of Copper Carbonate (Product) = ?

Solution:
⇒ According to the "Law of Conservation of Mass", mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations, i,e,  the mass of the products in a chemical reaction must equal the mass of the reactants.

⇒ Total mass of reactants = Total mass of Products

⇒ Mass of Copper sulphate (Reactant) + Mass of Sodium Carbonate (Reactant) =  Mass of Sodium sulphate (Product) + Mass of Copper Carbonate (Product)

⇒ Let us assume the unknown mass of copper carbonate (Product) to be x.
⇒ 31.9 + 21.2 = 28.4 + x
⇒ 53.1 = 28.4 + x
⇒ 53.1 - 28.4 = x
⇒ ∴X = 24.7g

⇒Hence, the mass of Copper carbonate(Product) = 24.7g.

⇒ The law that governs the same is the "Law of conservation of mass"

:)

Answer 2

Hey there!
Down here⏬

Copper Sulphate {CuSo4} = 31.9g

Soduim Carbonate {Na2O3} = 21.2g

Soduim Sulphate {Na2So4} = 28.4g

Copper Carbonate {Cu2(OH)2CO3} = ?

Chemical Equation

$cuso4 \: + \: na2co3 \:(products) = \: cu2( oh)2co3 \: + \: na2so4(reactants)$

According to the law of Conversations of Mass by Proust, The mass of products is equal to mass of reactants

$reactants = products \: (weight)$

Let the amt of copper sulphate be x

$31.9 + 21.2 = x + 28.4$

$53.1 = x + 28.4$

$x = 53.1 - 28.4$

$x = 24.7$

So, the amount of Copper Carbonate {Cu2(OH)2Co3} = 24.7 g

(According to Law of Conservation of Mass)

Hope it helps.