Question

Lars is balancing equations with his study group. He is unsure about one equation because each member of the study group came up with a different answer. Which is the proper way to balance the equation Ca(OH)2 + H3PO4 ? Ca3(PO4)2 + H2O?

Answer 1

Answer: It is options 2

Explanation:

I took the test

Answer 2

Answer:

Explanation:

We are given that an equation

$Ca(OH)_2+H_3PO_4\rightarrow Ca_3(PO_4)2+H_2O$

We have to find the proper way to balance the equation

Calculate number of  atoms each type of element on left hand side and on right side

On left hand side

Number of atoms of Ca=1

Number of oxygen atoms=6

Number of phosphorous atom=1

Number of hydrogen atoms=5

On right hand side

Number of  Ca atoms=3

Number of oxygen atoms=9

Number of phosphorous atom=2

Number of hydrogen atoms=2

We substitute 3 as stoichiometric coefficient of $Ca(OH)_2$ and 2 as stoichiometric coefficient of $H_3PO_4$

Then, the equation

$3Ca(OH)_2+2H_3PO_4\rightarrow Ca_3(PO_4)_2+H_2O$

Now,Number of oxygen on left side =14

Number of hydrogen atom on left side =12

Therefore, we substituting 6 as stoichiometric coefficient of water

Then ,we get

$3Ca(OH)_2+2H_3PO_4\rightarrow Ca_3(PO_4)_2+6H_2O$

Now, we have on left side

Total number of oxygen atom=14

Total number of hydrogen atom=12

Total number of phosphorous atom=2

Total number of Ca atom=3

On right side

Total number of oxygen atom=14

Number of hydrogen atom=12

Number of phosphorous atom=2

Number of Ca atom=3

Hence, the equation is balance.