In two or more complete sentences explain how to balance the chemical equation and classify its reaction type.
+ ⟶ +

Explanation:

Reaction Given:

___H₃PO₄ + ___NaBr ⟶ ___HBr + ___Na₃PO₄

Balance Equation = ?

Type of reaction =?

Solution:

Balance Chemical Equation:

A balanced chemical equation is that in which the number of the reactant atoms equal to the number of the product atom.

For example if the hydrogen at the reactant side is 3, the number of hydrogen must be 3 on the product side.

Check the chemical equation and count the number of atoms at the reactant side and product side.

If the number of atoms of the reactants equal to the number of atoms of products then the reaction is balanced but if not equal, then reaction is not balanced

Balancing is an trial and error process to get a balance reaction.

First we count the number of atoms of reactant and product

Number of atoms of Reactant:

H = 3

P = 1

O = 4

Na = 1

Br = 1

Number of atoms of Product:

H = 1

P = 1

O = 4

Na = 3

Br = 1

So this is not a balance equation as the atoms of the reactant atoms not equal to the number of the product atoms.

As there are 3 hydrogen, and 1 sodium atom at reactant side but 1 hydrogen atom and 3 sodium atoms at the product side so we balance this along with other

Balanced Equation:

H₃PO₄ + 3 NaBr ⟶ 3 HBr + Na₃PO₄

Now count the number of atoms of reactant and product

Number of atoms of Reactant:

H = 3

P = 1

O = 4

Na = 3

Br = 3

Number of atoms of Product:

H = 1

P = 1

O = 4

Na = 3

Br = 1

Now this reaction is balanced as the atoms of the reactant atoms equal to the number of the product atoms.

So, the Coefficient of NaBr and HBr is 3 in balanced equation

Type of Reaction:

This is a double displacement reaction, in which Hydrogen (H) of the first compound replace the Sodium (Na) of the other compound or and Phosphate (PO₄) of the first compound replace the bromine (Br) of the other compound . Two molecule or compound combine and produce a two other molecule or compound different from reactants.

Reaction Type = Double displacement

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"