Reaction Action!
When a chemical reaction occurs, the total number of these stays the same, even if their arrangement changes.
atoms
A reaction that releases energy and makes the surroundings warmer is called this.
exothermic
What is the most important thing in a lab?
Safety
What are the steps of the engineering design process?
Define the problem
Brainstorm
Plan and Design
Build and Create
Test and Analyze
Reflect and Improve
Communicate
This gas makes up the largest percentage of the air we breathe.
Nitrogen
What are some signs of a chemical reaction?
Temp change, color change, formation of a precipitate, etc..
The process of ice melting absorbs heat from the environment. What type of reaction is this?
endothermic
How could you tell a reaction is producing a gas?
Bubbles, fizz, foam, expansion, increased pressure
What role does failure play in the engineering design process?
It tells us how and what to improve and allows us to refine a design
The boiling point of water is 100°C, but at higher altitudes, does it increase or decrease?
Decreases
When magnesium burns, it reacts with oxygen to form magnesium oxide. If you started with 10g of magnesium and ended with 16g of magnesium oxide, how much oxygen was used?
6g
In an endothermic reaction, what happens to the temperature of the surrounding area?
decreases
If the chemical formula for producing a sandwich is 2B+C=(2BC), in which (2BC) = sandwich, then how many sandwiches would 4 Breads and 3 Cheeses produce?
2 sandwiches and one leftover cheese
What is one real-world factor we have to consider when designing a heat pack?
safety, cost, portability, rate of heat, environmental concerns
Some reactions, like rusting, happen very slowly. What is one way to speed up a chemical reaction?
increase temperature, use a catalyst, or increase surface area
When balancing a chemical equation, this is the only thing you are allowed to change to make sure mass is conserved.
coefficients
What is being transferred in endothermic and exothermic reactions?
Energy, usually in the form of heat and light but not always
In the hot hands lab, what did the energy start as and what did it end up as?
Chemical potential energy to thermal energy
If a heat pack needs to stay warm for at least 30 minutes, but your design only lasts 10 minutes, what could you adjust
amount of reactants or the reaction speed
If you put a balloon in the freezer, it shrinks. What happens to the air molecules inside to cause this?
they move slower and take up less space
If a solid and liquid react to form a gas and bubbles, where did the gas come from?
the rearrangement of atoms in the reactants
This exothermic reaction occurs in cars and engines, using fuel and oxygen to release energy.
combustion
SPECIFICALLY, What kind of chemical reaction happened in the hot hands lab?
Oxidation Reaction
Why is quantitative data (exact temperature measurements) better than qualitative data for our evaluation of different reactions?
Quantitative data is objective and cannot be biased
What is it called when water can boil and freeze at the same time?
the triple point