Answer:
2 AsCl₃ + 3 H₂S → As₂S₃ + 6 HCl
Explanation:
When we balance a chemical equation, what we are trying to do is to achieve the same number of atoms for each element on both sides of the arrow. On the right of the arrow is where we can find the products, while the reactants are found on the left of the arrow.
We usually balance O and H atoms last.
AsCl₃ + H₂S → As₂S₃ +HCl
<u>reactants</u>
As --- 1
Cl --- 3
H --- 2
S --- 1
<u>products</u>
As --- 2
Cl --- 1
H --- 1
S --- 3
2 AsCl₃ + H₂S → As₂S₃ +HCl
<u>reactants</u>
As --- 2
Cl --- 6
H --- 2
S --- 1
<u>products</u>
As --- 2
Cl --- 1
H --- 1
S --- 3
The number of As atoms is now balanced.
2 AsCl₃ + 3 H₂S → As₂S₃ +HCl
<u>reactants</u>
As --- 2
Cl --- 6
H --- 6
S --- 3
<u>products</u>
As --- 2
Cl --- 1
H --- 1
S --- 3
The number of S atoms is now equal on both sides.
2 AsCl₃ + 3 H₂S → As₂S₃ + 6 HCl
<u>reactants</u>
As --- 2
Cl --- 6
H --- 6
S --- 3
<u>products</u>
As --- 2
Cl --- 6
H --- 6
S --- 3
The equation is now balanced.
There are two valence electrons in a single atom of magnesium.
Answer:
1. 12.6 moles
2. 8.95 moles
3. 2A + 5B → 3C
4. 48 moles
Explanation:
1. 2Fe + 3Cl₂ → 2FeCl₃
We assume the chlorine in excess. Ratio is 2:2
2 moles of Fe, can produce 2 moles of chloride
12.6 moles of Fe will produce 12.6 moles of chloride.
2. 2Fe + 3Cl₂ → 2FeCl₃
For the same reaction, first of all we need to convert the mass to moles:
500 g . 1mol / 55.85 g = 8.95 mol
As ratio is 2:2, the moles we have are the same, that the produced
4. The reaction for the combustion is:
2C₂H₆ (g) + 7O₂ (g) → 4CO₂ (g) + 6H₂O (l)
We assume the oxygen in excess.
Ratio is 2:6, so 2 mol of ethane produce 6 moles of water
Therefore 16 moles of ethane may produce (16 .6) / 2 = 48 moles
Answer:
The system gains 126100 J
Explanation:
The heat can be calculated by the equation:
Q = nxCxΔT, where Q is the heat, C is the heat capacity,n is the number of moles and ΔT is the variation of temperature (final - initial). The number of moles is the mass divided by the molar mass, so:
n = 250/4 = 62.5 mol.
The system must be in thermal equilibrium with the surroundings, so if the temperature of the surroundings decreased 97 K, the temperature of the system increased by 97 K, so ΔT = 97 K
Q = 62.5x20.8x97
Q = 126100 J