Chemical/Physical Changes
When ice melts into water, is it a chemical or physical change?
Physical
In a balanced equation, the number of atoms on each side must be_________.
Equal
A system where matter and energy can enter and leave is called what?
Open system
In a chemical reaction, the total mass of the reactants must equal the total mass of the ______.
Products
Metals that contain iron are called what type of metals?
Ferrous Metals
When sugar dissolves in water, what type of change occurs?
Physical
True or False: Atoms can be created or destroyed in a chemical reaction.
False
Vinegar and baking soda reacting in an open beaker is what type of system?
Open system
True or False: Atoms cannot disappear during a chemical reaction.
True
Is copper a ferrous or non-ferrous metal?
Non Ferrous
A student mixes two chemicals and observes bubbles and heat. What type of change likely occurred?
Chemical
Which law requires chemical equations to be balanced?
Law of Conservation of Mass
What is the main difference between open and closed systems?
Whether matter can enter or leave the system.
If 10 g of reactants are used, how many grams of products should form?
10 g
The liquid inside a battery that helps electricity flow is called what?
Electrolyte
Explain why rusting iron is considered a chemical change instead of a physical change.
Because iron reacts with oxygen to form a new substance.
Balance the following equation.
__Fe₂O₃ + __H₂ → __Fe + __H₂O
1,3,2,3
In a closed system, can energy still transfer?
Yes
Calculate the total mass of the products for the following equation.
NH₄NO₃ → N₂O + 2H₂O
80 amu
Please put the following in order for the steps of reclaiming a metal.
- Melting the bits at high temperatures to create pure metal bars.
- Shredding items into tiny small marble sized bits.
- Collecting scrap metal and old electronics.
- Sorting and separating metals by using magnets to separate steel from plastic.
4,3,1,2
Which of the following observations is the strongest evidence of a chemical change: melting, boiling, or formation of a precipitate?
formation of a precipitate
Balance the following equation.
__Al + __HCl → __AlCl₃ + __H₂
2,6,2,3
Why is sealing a reaction container important when studying chemical reactions?
To prevent loss of matter and accurately measure reactions.
Does the following equation follow the Law of Conservation of Mass?
C₄H₁₀ + 6O₂ → 4CO₂ + 5H₂O
No.
Reactants: 250 amu
Products: 262 amu
In electrolysis, which electrode is positive?
Anode