[A]0= Initial concentration
t1/2= half life
[A]= final concentration
k= rate constant
1. Double replacement (DR)
2. Decomposition (D)
<h3>Further explanation</h3>
1. Al2(SO4)3 + Ca3(PO4)2 -> 2AIPO4 + 3CaSO4
Double replacement (DR) : there is an ion exchange between two ion compounds in the reactant to form two new ion compounds in the product
General form :
AB + CD -> AD + CB
2. 2NaCIO3 → 2NaCl + 3O2
Decomposition (D) : Reactant breakdown into simpler ones(reverse of combination)
General form :
AB ---> A + B
Answer:
Option A.
2Na + 2H2O —> 2NaOH + H2
Explanation:
To know which option is correct, we shall do a head count of the number of atoms present on both side to see which of them is balanced. This is illustrated below below:
For Option A:
2Na + 2H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
4 H >>>>>>>>>>>> 4 H
2 O >>>>>>>>>>>> 2 O
Thus, the above equation is balanced.
For Option B:
2Na + 2H2O —> NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 3 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
For Option C:
2Na + H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
2 H >>>>>>>>>>>> 4 H
1 O >>>>>>>>>>>> 2 O
Thus, the above equation is not balanced.
For Option D:
Na + 2H2O —> NaOH + 2H2
Reactant >>>>>>> Product
1 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 5 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
From the illustrations made above, only option A is balanced.