1. A chemist wants to synthesize ammonia, which has the chemical formula NH₃. Which of the following reactant lists is the only one that could possibly be used to produce ammonia?
- A. Methane (CH₄) and water (H₂O)
- B. Nitrogen gas (N₂) and hydrogen gas (H₂)
- C. Carbon dioxide (CO₂) and hydrogen gas (H₂)
- D. Sodium chloride (NaCl) and water (H₂O)
2. In a crime lab, a residue is identified as iron sulfide (FeS). According to the Law of Conservation of Matter, which element must have been present in the materials used to create this residue?
- A. Silicon (Si)
- B. Oxygen (O)
- C. Sulfur (S)
- D. Sodium (Na)
3. A student incorrectly claims that they can produce carbon dioxide (CO₂) by reacting pure hydrogen gas (H₂) with pure oxygen gas (O₂). Why is this impossible?
- A. The reaction would produce water (H₂O) instead, as no carbon atoms are available in the reactants.
- B. The reaction requires a metal catalyst, which was not mentioned as being present in the experiment.
- C. Hydrogen and oxygen are both non-metals and therefore cannot react with each other to form a new compound.
- D. Carbon dioxide is a stable molecule and can only be formed by breaking down more complex organic matter.
4. Which scientific law is the primary reason why you cannot create water (H₂O) from a mixture of only nitrogen (N₂) and hydrogen (H₂)?
- A. The Law of Conservation of Energy
- B. The Law of Universal Gravitation
- C. The Law of Conservation of Matter
- D. The Law of Definite Proportions
5. The Law of Conservation of Matter means that in any balanced chemical equation, which of the following must be true?
- A. The number of molecules on the reactant side must equal the number of molecules on the product side.
- B. The number of atoms of each element on the reactant side must equal the number of atoms of that same element on the product side.
- C. The physical state (solid, liquid, gas) of the reactants must be the same as the physical state of the products.
- D. The total electrical charge of the reactants must always be zero.
6. In any chemical synthesis, what is the fundamental requirement for the reactants used to create a specific product?
- A. The reactants must be in the same physical state (solid, liquid, or gas) as the desired product.
- B. The reactants must contain all the necessary types of atoms that make up the product molecule.
- C. The reactants must be heated to a very high temperature to initiate the chemical change.
- D. The reactants must be less complex than the product being formed.
7. A chemist wants to synthesize ammonia (NH₃), a compound made of nitrogen and hydrogen. Which combination of reactants could potentially be used?
- A. Methane (CH₄) and water (H₂O)
- B. Nitrogen gas (N₂) and hydrogen gas (H₂)
- C. Carbon dioxide (CO₂) and hydrogen gas (H₂)
- D. Salt (NaCl) and water (H₂O)
8. In the context of creating a new chemical substance, what are the 'reactants'?
- A. The tools used to mix the chemicals
- B. The starting materials that are combined
- C. The new substances formed in the reaction
- D. The energy released during the reaction
9. A scientist uses an atomic model to simulate mixing sulfuric acid (H₂SO₄) and sodium chloride (NaCl). The model shows that hydrofluoric acid (HF) cannot be formed. What is the fundamental reason for this outcome?
- A. The simulation is missing fluorine atoms.
- B. The simulation has too many hydrogen atoms.
- C. The simulation lacks the necessary sodium atoms.
- D. The simulation shows the reaction is too slow.
10. To synthesize hydrofluoric acid, which two types of atoms must be present in the starting materials?
- A. Hydrogen and Oxygen
- B. Hydrogen and Fluorine
- C. Helium and Fluorine
- D. Carbon and Hydrogen