Question

according to the law of conservation of mass, how much zinc was produced if calcium = 25 g, zinc carbonate = 75 g and calcium carbonate = 50 g
(a) 100 g
(b) 50 g
(c) 25 g

Explanation:

Step1: Recall Law of Conservation of Mass

The law states that mass of reactants = mass of products. Reactants: Calcium (25 g) + Zinc Carbonate (75 g). Products: Calcium Carbonate (50 g) + Zinc (x g).

Step2: Set Up Mass Equation

Total reactant mass: \( 25 + 75 = 100 \) g. Total product mass: \( 50 + x \) g.

Step3: Solve for x

Equate reactant and product masses: \( 100 = 50 + x \). So, \( x = 100 - 50 = 50 \) g? Wait, no—wait, wait, maybe I misread. Wait, reactants: Ca (25g) + ZnCO₃ (75g) = 100g. Products: CaCO₃ (50g) + Zn (x). So 25 +75 = 50 + x → x=50? But the option C is 25? Wait, maybe typo? Wait, no, let's check again. Wait, maybe the question is Calcium (25g), Zinc Carbonate (75g), Calcium Carbonate (50g). So mass of Zn: (25 +75) -50 = 50? But option B is 50? Wait, the options: A 100, B 50, C 25. Wait, maybe I messed up the reactants. Wait, the reaction: Ca + ZnCO₃ → CaCO₃ + Zn. So reactants: Ca (25g) + ZnCO₃ (75g) = 100g. Products: CaCO₃ (50g) + Zn (x). So x = 25 +75 -50 = 50g. So answer is B. 50g.

Answer:

B. 50 g