MRE Design
what MRE stands for
meal ready to eat
this needs to be added to activate a flameless heater
water
a substance that you have BEFORE a chemical reaction is called... (starts with R)
reactant
what we want our reaction to the elements in this experiment to do...what?
warm/heat up
Name a sign of a chemical reaction
Temperature change, color change, gas bubbles, or formation of a solid, mass change
something that your design HAS to have is called a... (starts with C)
criteria
For SCIENCE, we measure heat in degrees ________
Celsius
a substance you have AFTER a chemical reaction is called... (starts with P)
product
The atomic symbol for aluminum
Al
Why is melting ice not a chemical reaction?
No new substance formed, just a physical change
the combination of substances that got hotter, that we have tested in both labs now. (3 substances)
root killer, aluminium, and saltwater
Whats a reason why hand warmers are not a good alternative for MRE heaters ?
they do not get warm enough
they are too small
a reaction that gets warmer
exothermic reaction
What does doubling the concentration of the reactants do to the amount of heat produced?
It nearly doubles the amount of heat produced.
In a closed system, the total mass before a reaction is 50 grams. What will the mass be after?
50 grams
problems with MREs (name at least 1)
too expensive, not being accessible, and/or using dangerous chemicals
Name a difference between hand warmers & MRE heaters
MRE heaters get much hotter than the hand warmers
Flameless heaters are much bigger than hand warmers
handwarmers react to air, flameless heaters react in water
a reaction that gets colder
endothermic reaction
the scientific name for root killer
CuSO4
copper sulfate
What gas is formed when mixing vinegar and baking soda
CO2
what is the average cost of an MRE?
$10-15 on average
what happens to particles as they heat up
speed up
something that holds your design back or limits the design
constraint
Where does energy come from in an endothermic reaction
From the surroundings- energy is absorbed
What two reactants form rust (hint...don't use the words metal/water)
Iron and Oxygen