Significant Figures
How many significant figures are in 0.0045?
2
In a reaction inside a beaker, what is the system?
The Reaction
What does c represent in q=mcΔTq
Specefic Heat
What does a thermometer measure?
Tempature
Combustion reactions always require what gas?
Oxygen
How many significant figures are in 203?
3
Everything outside the system is called what?
Surroundings
What is the specific heat formula used to calculate heat?
q = mcΔT
What unit is most common in chemistry labs?
Celsius
Combustion reactions usually release or absorb heat?
Releases Heat
How many significant figures are in 5.200?
4
If water warms up during a reaction, did the reaction absorb or release heat?
Released Heat.
If mass doubles, what happens to heat energy (q)?
It doubles
What happens to liquid in a thermometer when temperature increases?
It expands
Combustion of hydrocarbons produces what two products?
CO₂ and H₂O
Round 3.476 × 2.1 to the correct significant figures.
7.3
What type of system allows energy but not matter to move?
Closed System
50 g of water warms by 10°C. What happens to q?
Heat is absorbed
What must you read at eye level to avoid measurement error?
The meniscus
Is combustion endothermic or exothermic?
Exothermic
How many significant figures are in 0.02030?
4
What type of system allows neither matter nor energy to move?
Isolated system
Calculate heat:
m = 20 g, c = 4.18, ΔT = 5°C
418 J
If temperature rises, what happens to particle motion?
Particles move faster
Balance combustion:
CH₄ + O₂ → CO₂ + H₂O
CH₄ + 2O₂ → CO₂ + 2H₂O