PLEASE VERY IMPORTANT NEED THIS All of the questions will refer to the unbalanced equation below in the image. Balance it, then answer all of the questions.

1. What is the correct value for coefficient (A)? 1, 2, 3 or 4

2. What is the correct value for coefficient (B)? 1, 2, 3 or 4

3. What is the correct value for coefficient (C)? 1, 2, 3 or 4

4. What is the correct value for coefficient (D)? 1, 2, 3 or 4

5. If there is enough energy and H2, then how many moles of Sn02 will react with 2 miles of H2 and produce 1 mole of Sn and 2 moles of H2O? How many moles of SnO2 does this balanced equation represent? 0.5, 1.0, 1.5 or 2.5

6. The reactants in this equation are _. SnO2 and Sn, Sn and H2O, SnO2 and H2 OR H2 and H2O

7. The products in this equation are _. SnO2 and Sn, Sn and H2O, SnO2 and H2 OR H2 and H2O

8. The reaction is _. Endothermic OR exothermic

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:

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.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.