Question

instructions: count the atoms on the reactant side of the equation and on the product side. based on the atom counts, decide if the chemical equation is following the law of conservation of mass or not. circle yes if it is and no if it isnt.

1. 3h₂ + 2o → 2h₂o

h =
o =
h =
o =
yes
no

1. n₂ + 3h₂ → 2nh₃

n =
h =
n =
h =
yes
no

1. 2al + 2hcl → 3h₂ + 2alcl₃

al =
h =
cl =
al =
h =
cl =
yes
no

Explanation:

Step1: Count reactant - side atoms for $3H_2 + 2O

ightarrow2H_2O$
For hydrogen ($H$) in reactants: $3\times2 = 6$; for oxygen ($O$) in reactants: $2$.

Step2: Count product - side atoms for $3H_2 + 2O

ightarrow2H_2O$
For hydrogen ($H$) in products: $2\times2 = 4$; for oxygen ($O$) in products: $2$. Since $6
eq4$ for hydrogen, this equation violates the law of conservation of mass.

Step3: Count reactant - side atoms for $N_2+3H_2

ightarrow2NH_3$
For nitrogen ($N$) in reactants: $2$; for hydrogen ($H$) in reactants: $3\times2 = 6$.

Step4: Count product - side atoms for $N_2+3H_2

ightarrow2NH_3$
For nitrogen ($N$) in products: $2\times1 = 2$; for hydrogen ($H$) in products: $2\times3 = 6$. This equation follows the law of conservation of mass.

Step5: Count reactant - side atoms for $2Al + 2HCl

ightarrow3H_2+2AlCl_3$
For aluminum ($Al$) in reactants: $2$; for hydrogen ($H$) in reactants: $2$; for chlorine ($Cl$) in reactants: $2$.

Step6: Count product - side atoms for $2Al + 2HCl

ightarrow3H_2+2AlCl_3$
For aluminum ($Al$) in products: $2$; for hydrogen ($H$) in products: $3\times2 = 6$; for chlorine ($Cl$) in products: $2\times3 = 6$. Since $2
eq6$ for hydrogen and $2
eq6$ for chlorine, this equation violates the law of conservation of mass.

Answer:

1. $H = 6$, $O = 2$ (reactants); $H = 4$, $O = 2$ (products); No
2. $N = 2$, $H = 6$ (reactants); $N = 2$, $H = 6$ (products); Yes
3. $Al = 2$, $H = 2$, $Cl = 2$ (reactants); $Al = 2$, $H = 6$, $Cl = 6$ (products); No