Na2 + 2HCl 2NaCl + H2

Can you find it?

2

All metals that are in their “elemental” state; that is not bound up with a nonmetal,has a subscript of 1

2Na + 2HCl 2NaCl + H2

2Na + 2HCl 2NaCl + H

Can you find it?

The elements H2 N2 O2 F2 Cl2 Br2 and I2 when all bythemselves (in the elemental form) always carry a subscript of 2

2Na + 2HCl 2NaCl + H2

2

Fe(II)(OH)2+ 2HCl Fe(II)Cl2 + 2H2O

Can you find it?

The roman numerals DO not appear in the middle of the formulathey only appear in the name ie: iron (II) hydroxide.

Fe(OH)2 + 2HCl FeCl2 + 2H2O

Cu(aq)Cl2 + H2S Cu(s)S + 2HCl

Can you find it?

The labels (aq) (s) (l) etc are always placed behind the formulanever in the middle.

CuCl2(aq) + H2S CuS(aq) + 2HCl

NaBr + H3PO4 NaPO4 + HBr

Can you find it?

This equation CANNOT balance because the subscripts werecarelessly put on.

3NaBr + H3PO4 Na3PO4 + 3HBr

Mg(s)+ 2Ag(NO3) MgNO3 2 + 2Ag(s)

Can you find it?

Careless use of parenthesis. None were needed on the leftside (only one nitrate) and none were placed on the right sidewhere they were needed.

Mg(s)+ 2AgNO3 Mg(NO3)2 + 2Ag(s)

CuCl(s)+ (H2)2 S CuS + 4HCl(aq)

Can you find it?

This shows that one mistake leads to others. In this formulaHydrogen is not written correctly on the left side. The parenthesisis not to be used in hydrogen unless it is alone as a gas H2

Also, this equation cannot be balanced because of that mistake leading to further errors. GET THE SUBSCRIPTS AND PARENTHESIS RIGHT FIRST, THEN BALANCE THE EQUATION.

CuCls)+ H2S Cu2S + HCl(aq)

NaBr + H3PO4 NaH3 + Br3PO4

Can you find the biggest mistake here?

The positive element were joined with the positive elementsand the negative elements with the negative elements. This is a very big NO NO! Only put positive elements with negative ones.

3NaBr + H3PO4 Na3PO4+ 3HBr

Can you find the biggest mistake here?

2FeNO + 3K2S 2K3NO + Fe2S3

There are several mistakes here but the biggest one is notwriting nitrate correctly (nitrate is NO3) This messed up otherparts of the formula. Also, the charge on the nitrate is uncertainbecause on the right side you have 3 potassium attached to onenitrate leading on to believe it has a charge of –3 when it is actually-1

2Fe(NO3)3 + 3K2S 6KNO3 + Fe2S3

Can you find the biggest mistake here?

Mg(s)+ Ag3NO3(aq)MgNO3(aq) + 3Ag(s)

There are several mistakes here but maybe the biggest one is failure to getthe individual formulas right for each compound. This is critical to do before you attempt to balance the equation with coefficients. NO3 is always -1 but this equation makes it to be a –3 on the left and a –2 on the right! Puttingcoefficients in front becomes meaningless!

Mg(s)+ 2AgNO3(aq)Mg(NO3)2(aq) + 2Ag(s)