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Number 1 is really hard…. If you can please do 6 and 7…..

Number 1 is really hard…. If you can please do 6 and 7…..-example-1
User Lorenzo D
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1 Answer

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6.

___ (NH₄)₃PO₄ + ___ Pb(NO₃)₄ ----> ___ Pb₃(PO₄)₄ + ___ NH₄NO₃

The easiest way to balance this kind of reaction is to consider the ions, not the elements alone. So we split the reaction into ions and we will balance them.

___ (NH₄)₃PO₄ + ___ Pb(NO₃)₄ ----> ___ Pb₃(PO₄)₄ + ___ NH₄NO₃

NH₄: 3 NH₄: 1

PO₄: 1 PO₄: 4

Pb: 1 Pb: 3

NO₃: 4 NO₃: 1

We have 3 ammonium ions on the left and just 1 ammonium ion on the right. We can change the coefficient for NH₄NO₃ and write a 3 in front of it.

4 (NH₄)₃PO₄ + ___ Pb(NO₃)₄ ----> ___ Pb₃(PO₄)₄ + 3 NH₄NO₃

NH₄: 3 NH₄: 3

PO₄: 1 PO₄: 4

Pb: 1 Pb: 3

NO₃: 4 NO₃: 3

Now the NH₄ is balanced. We have 4 phosphate ion on the right and just one on the left. We can change the coefficient for (NH₄)₃PO₄ and write a 4 there.

4 (NH₄)₃PO₄ + ___ Pb(NO₃)₄ ----> ___ Pb₃(PO₄)₄ + 3 NH₄NO₃

NH₄: 12 NH₄: 3

PO₄: 4 PO₄: 4

Pb: 1 Pb: 3

NO₃: 4 NO₃: 3

We balanced the PO₄ but unbalanced the NH₄, Let's go back to NH₄. We have 12 ions on the left and 3 on the left. The coefficient for NH₄NO₃ must be 12.

4 (NH₄)₃PO₄ + ___ Pb(NO₃)₄ ----> ___ Pb₃(PO₄)₄ + 12 NH₄NO₃

NH₄: 12 NH₄: 12

PO₄: 4 PO₄: 4

Pb: 1 Pb: 3

NO₃: 4 NO₃: 12

We can go on with Pb. We have 3 on the right and 1 on the left. We can change the coefficient for Pb(NO₃)₄ and write a 3.

4 (NH₄)₃PO₄ + 3 Pb(NO₃)₄ ----> ___ Pb₃(PO₄)₄ + 12 NH₄NO₃

NH₄: 12 NH₄: 12

PO₄: 4 PO₄: 4

Pb: 3 Pb: 3

NO₃: 12 NO₃: 12

And the equation is balanced.

Answer: 4 (NH₄)₃PO₄ + 3 Pb(NO₃)₄ ----> Pb₃(PO₄)₄ + 12 NH₄NO₃

7.

SnO₂ + ___ H₂ ----> Sn + ___ H₂O

Sn: 1 Sn: 1

O: 2 O: 1

H: 2 H: 2

The Sn is already balanced, but O is not. We have two atoms of O on the left and only 1 atom of O on the right side of the equation. We can change the coefficient in front of H₂O.

SnO₂ + ___ H₂ ----> Sn + 2 H₂O

Sn: 1 Sn: 1

O: 2 O: 2

H: 2 H: 4

We balanced the O, but we unbalanced the H. Now we have 4 atoms of H on the right and 2 atoms of H on the left side of the equation. So if we change the coefficient of H₂ and write a 2 we will balance the equation.

SnO₂ + 2 H₂ ----> Sn + 2 H₂O

Sn: 1 Sn: 1

O: 2 O: 2

H: 4 H: 4

Answer: SnO₂ + 2 H₂ ----> Sn + 2 H₂O

User Laxxy
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