A 70.0-g iron nail combines with 30.0 g of oxygen to form rust. What is the total mass of the iron nail plus the rust that forms?

• A. 40.0 g
• B. 100.0 g
• C. 230.0 g
• D. It depends on the type of rust that is formed.
• E. There is not enough information to determine the total mass.

Answer: (B)

Verified step by step guidance

1. Identify the law of conservation of mass, which states that mass is neither created nor destroyed in a chemical reaction. Therefore, the total mass of the reactants must equal the total mass of the products.
2. Determine the mass of the reactants. In this case, the reactants are the iron nail and the oxygen. The mass of the iron nail is 70.0 g, and the mass of the oxygen is 30.0 g.
3. Calculate the total mass of the reactants by adding the mass of the iron nail and the mass of the oxygen: 70.0 g + 30.0 g.
4. Understand that the rust formed is the product of the reaction between the iron nail and the oxygen. According to the law of conservation of mass, the total mass of the rust and any remaining iron nail should equal the total mass of the reactants.
5. Conclude that the total mass of the iron nail plus the rust that forms is the sum of the masses of the iron and oxygen, which is the total mass of the reactants.