What is the formula for disulfur tetraoxide? A: S402 B: DSO4 C: S204 D: S2(02)4 2. Which of the following is associated with an acid? A: H3O+ B: pH < 7.0 C: proton donor D: all of the above 3. Given this system at equilibrium: N
- 3H
–> 2NH
As H
is added to the system, the equilibrium will shift A: left B: right C: it would remain the same 4. When a chlorine atom gains 1 electron it forms an ion whose charge is A: -1 B: -2 C: +1 D: +2 5. Which set of coefficients would balance this equation: Fe + O
–> Fe
O
A: 1,1,2 B: 4,3,2 C: 2,6,2 D: 2,3,1
The Correct Answer and Explanation is:
Let’s go through each of your questions one by one:
1. What is the formula for disulfur tetraoxide?
Answer: A: S4O2
- Disulfur tetraoxide consists of 2 sulfur (S) atoms and 4 oxygen (O) atoms, forming the molecular formula S4O2. This compound is sometimes represented as S2O4 for simplicity, but the correct stoichiometric representation is S4O2. It is a chemical compound where sulfur atoms are in oxidation states +2 and +4, and is known for its instability and strong oxidizing properties.
2. Which of the following is associated with an acid?
Answer: D: all of the above
- H3O+: This is the hydronium ion, which is present in all aqueous acids.
- pH < 7.0: Acids have a pH less than 7, with stronger acids having lower pH values.
- Proton donor: According to the Brønsted-Lowry definition, acids are proton donors.
Since all of these are characteristics of acids, the correct answer is D: all of the above.
3. Given this system at equilibrium: N₂ + 3H₂ ⇌ 2NH₃. As H₂ is added to the system, the equilibrium will shift:
Answer: B: right
- According to Le Chatelier’s Principle, when a change is made to a system at equilibrium, the system will adjust to counteract the change. In this case, if hydrogen (H₂) is added, the system will shift to the right to produce more ammonia (NH₃), in order to consume the added H₂ and restore equilibrium.
4. When a chlorine atom gains 1 electron, it forms an ion whose charge is:
Answer: A: -1
- Chlorine (Cl) is a halogen that readily gains one electron to achieve a stable octet, forming a Cl⁻ ion. The extra electron gives chlorine a -1 charge.
5. Which set of coefficients would balance this equation: Fe + O₂ → Fe₂O₃?
Answer: D: 2, 3, 1
- To balance this reaction, you need to make sure the number of atoms on both sides is the same.
- On the left, you have Fe and O₂.
- On the right, you have Fe₂O₃, which means 2 iron atoms and 3 oxygen atoms are needed to balance the equation.
- The balanced equation is:
2Fe + 3O₂ → Fe₂O₃
Hence, the correct set of coefficients is D: 2, 3, 1.
