Respuesta :
Answer:
a. K₂CrO₄ + Pb(NO₃)₂ -------------> PbCrO₄ + 2 KNO₃
b. Mass of PbCrOâ‚„= 32.3 g
Explanation:
Part a
Data Given:
Reactants:
potassium chromate reacts with a solution of lead(II) nitrate
Product
lead(II) chromate and a solution of potassium nitrate
balanced chemical equation= ?
Solution:
Balance Chemical Equation:
A balanced chemical equation is that in which the number of the reactant atoms equal to the number of the product atom.
- First we write formulas for the reactants and products
Formulas of the Reactants
potassium chromate= Kâ‚‚CrOâ‚„
lead(II) nitrate = Pb(NO₃)₂
Formulas of products
lead(II) chromate = PbCrOâ‚„
potassium nitrate KNO₃
- now wright a complete chemical Reaction:
potassium chromate reacts with a solution of lead(II) nitrate to produce a yellow precipitate of lead(II) chromate and a solution of potassium nitrate.
Complete reaction is as under
            K₂CrO₄ + Pb(NO₃)₂ -------------> PbCrO₄ + KNO₃
Check the chemical equation and count the number of atoms at the reactant side and product side.
If the number of atoms of the reactants equal to the number of atoms of products then the reaction is balanced but if not equal, then reaction is not balanced
Balancing is an trial and error process to get a balance reaction.
Balanced Equation:
    K₂CrO₄ + Pb(NO₃)₂ -------------> PbCrO₄ + 2 KNO₃
Now count the number of atoms of reactant and product
Number of atoms of Reactant:
K = 2
Cr = 1
O = 10
Pb = 1
N = 2
Number of atoms of Product:
K = 2
Cr = 1
O = 10
Pb = 1
N = 2
Now this reaction is balanced as the atoms of the reactant atoms equal to the number of the product atoms.
So, the Coefficient of KNO₃ is 2 in balanced equation
___________
Part b
Given Data
Amount of potassium chromate = 0.1 mol
Mass of  lead chromate = ?
Solution:
First we look at the balanced chemical reaction for more details
Balanced Equation:
    K₂CrO₄ + Pb(NO₃)₂ -------------> PbCrO₄ + 2 KNO₃
      1 mol                      1 mol
As,
It is cleared from the reaction, that 1 mole of potassium chromate produce 1 mole of lead chromate
So,
It 0.1 mole of potassium chromate will must produce 0.1 mole of lead chromate.
        1 mole of  K₂CrO₄ ≅ 1 mole of PbCrO₄
        0.1 mole of  K₂CrO₄ ≅ 0.1 mole of PbCrO₄
To Calculate mass we have to convert moles of PbCrOâ‚„ to mass
Formula used
       Mass = no.of moles x molar mass
Molar mass of PbCrOâ‚„ = 323 g/mol
Put values in above formula
        Mass = 0.1 mole x 323 g/mol
        Mass = 32.3 g
Mass of PbCrOâ‚„= 32.3 g
