Temperature and Heat conversions
Convert 25 C to Kelvins
298.15 K
What is specific heat
The amount of energy (q) it takes to raise 1g of a substance by 1 C
Is melting aluminum a physical or chemical change?
Physical!
If an object is moving what type of energy is being used?
Kinetic Energy
Convert 345 Joules to calories (lower case)
82.457 calories!
If you get a negative value for q, does that mean that energy was released (lost) or absorbed (gained)?
Released
The ocean falls under what classification of matter?
Heterogenous Mixture
If you're not sure a reaction has taken place, what is one thing you can look for, in terms of energy?
Loss/gain of heat
How many joules of heat are required to raise the temperature of 550 g of water from 12 C to 18 C?
13,814 joules
How much energy, in joules, is needed to heat a 125 g sample of water from 20 °C to 100 °C?
41,800 Joules
What phase has an indefinite shape, but a definite volume?
Liquid phase!
Convert 600 J to calories (little c)?
143.403 calories
If I have a sandwich with 4 grams of protein in it, how many kilocalories (kcal) of the sandwich is coming from the protein?
36 kcal
A 250 g sample of water with an initial temperature of 98.8 C loses 7500 joules of heat. The specific heat of water is 4,1864 J/kg·°C What is the final temperature of the water?
91.6 C
If a substance is chemically combined in a standardized ratio, what classification of matter does it fall under?
pure substance/ compound/ element
ex: H2O
What is the specific heat of an element if 5g of the element going from 100C to 50C released -100J of heat?
*Look at givens and needs
0.4 J/g C
How much energy, in both joules and calories does it take to boil a 125 g sample of water?
282,000 Joules and 6739.96 calories
What is the mass of a sample of Nickel, which completely melts after 3120 J of heat? (∆Hfus of nickel is 298 J/g)
10.5 grams
Which state of matter has particles that move very slowly?
Solids!
How many calories are released in a reaction of 12 g of an substance that was heated from 76C to 86C, with a specific heat of 15.6 J/g C
*Make sure to convert!
447.42 calories