Balance the equation.
Cu + HNO3 --> Cu(NO3)2 + NO2 + H2O
I'm having a little trouble getting this equation to balance. Thank you in advance! :)
This is the equation with Cu and concentrated HNO3.
Cu + 4HNO3 ==> Cu(NO3)2 + 2H2O + 2NO2
To balance the equation Cu + HNO3 --> Cu(NO3)2 + NO2 + H2O, you need to make sure there is an equal number of atoms on both sides of the equation.
Here is the step-by-step process to balance the equation:
Step 1: Count the number of atoms of each element on both sides of the equation.
Left side:
Cu: 1 atom
H: 1 atom
N: 1 atom
O: 3 atoms
Right side:
Cu: 1 atom
N: 2 atoms
O: 7 atoms
H: 2 atoms
Step 2: Start with the element that appears in the fewest number of molecules or compounds. In this case, it is Cu.
Add a coefficient in front of Cu on the left side to balance the number of Cu atoms:
Cu + HNO3 --> Cu(NO3)2 + NO2 + H2O
Left side:
Cu: 1 atom
H: 1 atom
N: 1 atom
O: 3 atoms
Right side:
Cu: 1 atom
N: 2 atoms
O: 7 atoms
H: 2 atoms
Step 3: Count the number of atoms of each element again to see what is still unbalanced.
Left side:
Cu: 1 atom
H: 1 atom
N: 1 atom
O: 3 atoms
Right side:
Cu: 1 atom
N: 2 atoms
O: 7 atoms
H: 2 atoms
Step 4: Balance the nitrogen (N) atoms. There are already 2 nitrogen atoms on the right side, so we need to add a coefficient in front of HNO3 on the left side to balance the nitrogen atoms.
2 Cu + 2 HNO3 --> Cu(NO3)2 + NO2 + H2O
Left side:
Cu: 2 atoms
H: 2 atoms
N: 2 atoms
O: 6 atoms
Right side:
Cu: 1 atom
N: 2 atoms
O: 7 atoms
H: 2 atoms
Now, the nitrogen atoms are balanced.
Step 5: Count the number of atoms of each element again to see what is still unbalanced.
Left side:
Cu: 2 atoms
H: 2 atoms
N: 2 atoms
O: 6 atoms
Right side:
Cu: 1 atom
N: 2 atoms
O: 7 atoms
H: 2 atoms
Step 6: Balance the oxygen (O) atoms. There are already 6 oxygen atoms on the left side, so we need to add a coefficient in front of HNO3 on the left side to balance the oxygen atoms.
2 Cu + 4 HNO3 --> Cu(NO3)2 + NO2 + H2O
Left side:
Cu: 2 atoms
H: 4 atoms
N: 4 atoms
O: 12 atoms
Right side:
Cu: 1 atom
N: 2 atoms
O: 7 atoms
H: 2 atoms
Now, the oxygen atoms are balanced.
Step 7: Count the number of atoms of each element again to ensure everything is balanced.
Left side:
Cu: 2 atoms
H: 4 atoms
N: 4 atoms
O: 12 atoms
Right side:
Cu: 1 atom
N: 2 atoms
O: 7 atoms
H: 2 atoms
Now, both sides of the equation have an equal number of atoms, and the equation is balanced:
2 Cu + 4 HNO3 --> 2 Cu(NO3)2 + 4 NO2 + 2 H2O
To balance the equation:
Step 1: Count the number of atoms of each element on both sides of the equation.
Cu: 1 Cu atom on the left, 1 Cu atom on the right
H: 1 H atom on the left, 2 H atoms on the right
N: 1 N atom on the left, 2 N atoms on the right
O: 3 O atoms on the left, 5 O atoms on the right
Step 2: Start by balancing the atoms that appear in only one compound on each side of the equation.
Since Cu appears only in Cu(NO3)2 on the right side, place a coefficient of 1 in front of Cu(NO3)2 so that there is 1 Cu atom on both sides.
Cu + HNO3 --> 1Cu(NO3)2 + NO2 + H2O
Now the number of Cu atoms on both sides is balanced.
Step 3: Balance the elements next that are present in more than one compound on each side.
Counting the oxygen atoms, there are 3 on the left (from HNO3) and 5 on the right (3 from Cu(NO3)2 and 2 from H2O). To balance the oxygen, we need to add a coefficient of 2 in front of HNO3 and a coefficient of 4 in front of H2O.
Cu + 2HNO3 --> Cu(NO3)2 + NO2 + 4H2O
Now the number of oxygen atoms on both sides is balanced.
Step 4: Balance the remaining elements, which in this case is only hydrogen.
Counting the hydrogen atoms, there is 1 on the left (from HNO3) and 8 on the right (4 from H2O). To balance the hydrogen, we need to add a coefficient of 4 in front of HNO3.
Cu + 2HNO3 --> Cu(NO3)2 + NO2 + 4H2O
Now the equation is balanced with respect to all atoms.
Final balanced equation:
Cu + 2HNO3 --> Cu(NO3)2 + NO2 + 4H2O