Answer: (3) Energy is absorbed as bonds are broken, and energy is released as bonds are formed.
Explanation:
1) The equation given is H₂(g) + Cl₂(g) → 2HCl(g) + energy
2) The energy is shown in the product side, so energy is a product of the reaction, so energy is release.
But this is just the net energy of the process. You need more insight to deal with the energy changes in the reaction.
3) Chemical bonds store energy; this stored energy is the potential chemical energy of the molecules.
When a chemical reaction occurs, the first stage is to brake bonds.
Braking chemical bonds requires energy to overcome the bond energy. Braking bonds always absorbs energy.
On the other hand, forming bonds always release energy.
The neat energy of the reaction is the difference between the energy needed to break bonds and the energy released when new bonds form.
So, regardless the fact that, in the chemical equation that represents the reaction a net energy release is shown, you know that energy is absorbed as bonds are broken, and energy is released as bonds are formed (option 3).
Answer:
Zn + 2HCl → ZnCl2 + H2
Explanation:
Zn + HCl → ZnCl2 +
The complete equation is given below:
Zn+ HCl → ZnCl2 + H2
Now we can balance the equation by doing the following:
There are 2 atoms of Cl and 2 atoms of H on the left. This can be balanced by putting 2 in front of HCl as shown below:
Zn + 2HCl → ZnCl2 + H2
Answer:
612 K
Explanation:
From the question given above, the following data were obtained:
Initial temperature (T₁) = 306 K
Initial pressure (P₁) = 150 kPa
Final pressure (P₂) = 300 kPa
Volume = 4 L = constant
Final temperature (T₂) =?
Since the volume is constant, the final (i.e the new) temperature of the gas can be obtained as follow:
P₁ / T₁ = P₂ / T₂
150 / 306 = 300 / T₂
Cross multiply
150 × T₂ = 306 × 300
150 × T₂ = 91800
Divide both side by 150
T₂ = 91800 / 150
T₂ = 612 K
Thus, the new temperature of the gas is 612 K
Answer:
because the number of electrons and protons differs
