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How do you balance the equation and predict the product to identify the reaction...

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lizzyg | Student, Grade 11 | eNotes Newbie

Posted February 7, 2012 at 5:55 AM via web

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How do you balance the equation and predict the product to identify the reaction type?

1)_NiBr+_Pb->

2)decomposition of tin(lV) oxide produces

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bandmanjoe | Middle School Teacher | (Level 1) Senior Educator

Posted February 7, 2012 at 6:42 AM (Answer #1)

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On the subject of chemical equations, you need to understand you are mixing two things that are subject to react with each other.  The first example you have listed is what is called a single replacement reaction, where you have a compound, such as nickel bromide being reacted with lead.  The two metals, nickel and lead, will basically swap places, thus the name "single replacement":

NiBr + Pb --->  PbBr + Ni

To balance the equation, first you have to write the compound names properly.  Then, you count the number of atoms on both sides of the arrow.  When the numbers of atoms equal on both sides of the arrow, you have a balanced equation. 

Ni    Br    Pb    --->  Ni   Br    Pb

1      1     1              1    1     1

In this example, the equation is already balanced.

For the next example, tin (IV) oxide decomposing:

SnO2  ---->  Sn  +  O2

The number of atoms is the same again on both sides of the arrow, so no adjutment is needed.  If we did need to play with the numbers to equal the number of atoms, we would use a large number called a coefficient, placed in front of the compound we needed multiplied.  This equation is an example of a decomposition reaction, where a compound is breaking down.

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crazynitin1998 | Student, Grade 9 | Salutatorian

Posted February 7, 2012 at 11:42 PM (Answer #2)

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On the subject of chemical equations, you need to understand you are mixing two things that are subject to react with each other.  The first example you have listed is what is called a single replacement reaction, where you have a compound, such as nickel bromide being reacted with lead.  The two metals, nickel and lead, will basically swap places, thus the name "single replacement":

NiBr + Pb --->  PbBr + Ni

To balance the equation, first you have to write the compound names properly.  Then, you count the number of atoms on both sides of the arrow.  When the numbers of atoms equal on both sides of the arrow, you have a balanced equation.

Ni    Br    Pb    --->  Ni   Br    Pb

1      1     1              1    1     1

In this example, the equation is already balanced.

For the next example, tin (IV) oxide decomposing:

SnO2  ---->  Sn  +  O2

The number of atoms is the same again on both sides of the arrow, so no adjutment is needed.  If we did need to play with the numbers to equal the number of atoms, we would use a large number called a coefficient, placed in front of the compound we needed multiplied.  This equation is an example of a decomposition reaction, where a compound is breaking down.

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