Ijust want to check to see if the answer my child has is right.

2= Moles of SO₂ produced from 0.356 moles of PbS = 0.356 mol

3= Mass of hydrogen = 0.45 g

3= Mass of oxygen = 3.616  g

4 = Theoretical yield of P₂O₅ = 14.2 g.

Explanation:

Q2= Given data:

Moles of PbS = 0.356 mol

Moles of PbO = ?

Moles of SO₂ = ?

Solution:

Chemical equation:

2PbS + 3O₂  → 2PbO + 2SO₂

Now we will compare the moles of  PbS with PbO and SO₂ from balanced chemical equation.

                    PbS            :       PbO

                      2               :          2

                       0.356      :          0.356

Moles of PbO produced from 0.356 moles of PbS = 0.356 mol

                  PbS               :       SO₂

                    2                  :         2

                    0.356          :         0.356

Moles of SO₂ produced from 0.356 moles of PbS = 0.356 mol

Q= 3

Given data:

Mass of water = 4.05 g

Mass of hydrogen = ?

Mass of oxygen = ?

Solution:

Chemical equation:

2H₂O   →   2H₂  + O₂

Number of moles of water:

Number of moles of water = mass/ molar mass

Number of moles of water = 4.05 g/ 18 g/mol

Number of moles of water = 0.225 mol

Now we compare the moles of water with hydrogen and oxygen.

                             H₂O            :              H₂

                               2              :                2

                             0.225        :              0.225

Mass of hydrogen:

Mass of hydrogen = moles × molar mass

Mass of hydrogen =  0.225 mol × 2g/mol

Mass of hydrogen = 0.45 g

                              H₂O            :              O₂

                               2              :                1

                             0.225        :              1/2×0.225 = 0.113 mol

Mass of oxygen:

Mass of oxygen = moles × molar mass

Mass of oxygen =  0.113 mol × 32g/mol

Mass of oxygen = 3.616  g

Q 4

Given data:

Mass of phosphorus = 3.07 g

Mass of oxygen = 6.09 g

Theoretical yield of P₂O₅ = ?

Chemical equation:

4P + 5O₂  → 2P₂O₅

Number of moles of phosphorus = mass/ molar mass

Number of moles of phosphorus = 3.07 g/ 31 g/mol

Number of moles of phosphorus = 0.1 mol

Number of moles of oxygen = mass/ molar mass

Number of moles of oxygen = 6.09 g/ 32 g/mol

Number of moles of oxygen = 0.2 mol

Now we will compare the moles of P₂O₅ with oxygen and phosphorus.

             O₂          :        P₂O₅

              5           :           2

             0.2         :          2/5 ×0.2 =  0.08 mol

              P           :        P₂O₅

             4            :           2

            0.1           :           2/4×0.1 = 0.05 mol

The number of moles of P₂O₅ produced from phosphorus are less that's why phosphorus will be limiting reactant.

Mass of P₂O₅ = moles × molar mass

Mass of P₂O₅ = 0.05 mol × 283.88 g/mol

Mass of P₂O₅ = 14.2 g

Theoretical yield of P₂O₅ = 14.2 g.