Respuesta :
Answer:
1. A = 1; 2, B = 2; 3. C = 1; 4. D = 2; 5. 1 mol SnO₂, 1 mol;
6. SnO₂ and H₂; 7. Sn and H₂O; 8. Endothermic,
Explanation:
Often, the best way to start is to balance all atoms other than O and H, then balance O, then balance H.
1. Put a 1 in front of the most complicated-looking formula (SnO₂):
1SnO₂ + H₂ ⟶ Sn + H₂O
2. Balance Sn:
We have fixed 1 Sn on the left. We need only 1 Sn on the right. Put a 1 in front of Sn to fix it.
1SnO₂ + H₂ ⟶ 1Sn + H₂O
3. Balance O:
We have fixed 2 O on the left. We need 2 O on the right. Put a 2 in front of H₂O.
1SnO₂ + H₂ ⟶ 1Sn + 2H₂O
4. Balance H
We have fixed 4H on the right. We need 4H on the left. Put a 4 in froth of H₂.
1SnO₂ + 2H₂ ⟶ 1Sn + 2H₂O
Every formula now has a coefficient. The equation should be balanced.
5. Check that atoms balance:
[tex]\begin{array}{ccc}\textbf{Atom} & \textbf{On the left} & \textbf{On the right}\\\text{Sn} & 1 &1\\\text{O} & 2 & 2\\\text{H} & 4 & 4\\\end{array}[/tex]
It checks.
The balanced equation is
SnO₂ + 2H₂ ⟶ Sn + 2H₂O
6. Moles of SnO₂
According to the balanced equation,
1 mol of SnO₂ reacts with 2 mol of H₂.
The balanced equation represents 1 mol of SnO₂.
7. The reactants — on the left of the reaction arrow — are SnO₂ and H₂.
8. The products — on the right of the reaction arrow — are Sn and H₂O.
9. The energy is on the reactant side of the equation, so it is being added to the system.
The reaction is endothermic.