chemistry exam 1
heat
units of energy in joules and associated with the movement of particles
Converting Celsius to Fahrenheit
(C x 1.8) + 32
Converting Fahrenheit to Celsius
(F-32)/1.8
A 20 ounce bottle of soda provides a total of 300. Calories. How many kilojoules are in the soda?
1.26 x 10^3 kJ
SIG FIG: 0.00032 1.80 x10^6 30.0
2, 3, 3,
Freezing Point K, C, F
273, 0, 32
Calculate the number of kilojoules to warm 125 g of iron from 23.5 °C to 78.0 °C.
3.08
On a hot day, the thermometer read 95 °F. What is the temperature in degrees Celsius?
35
Boiling Point K,C,F
373, 100, 212
How many calories are required to raise the temperature of a 35.0 g sample of iron from 25 °C to 35 °C? Iron has a specific heat of 0.108 cal/g °C.
38 cal
The amount of energy required to heat water for a 10-minute shower (50 gallons) is 2.2125 kJ. How many calories is this?
5.2880 x 10^2 calories
If the temperature is 20. °C, what is the corresponding temperature on the Fahrenheit scale?
68
You and your friends are having lunch together and complaining about the cold weather. Kathy begins telling about her spring break trip to warm, sunny Spain. She starts to laugh when she tells the group that she was frustrated when she awoke on the first day to an outside temperature of 18° and a predicted high of 24°. Kathy was laughing because in Spain temperatures are measured in Celsius. What was the predicted high in Fahrenheit?
75
chemicals
substances that have the same composition wherever found
The energy associated with the motion of particles in a substance is called ________.
temperature heat chemical energy electrical energy potential energy
When a solid is converted directly to a gas, the change of state is called ________.
Sublimation
Substances A and B are the same mass and at the same initial temperature. When they are heated, the final temperature of A is 55 ∘C higher than the temperature of B. What does this tell you about the specific heats of A and B?
The specific heat of A must be more than the specific heat of B. The specific heat of A must be equal to the specific heat of B. The specific heat of A must be less than the specific heat of B.
When a liquid is boiling, its temperature does not change.
True
specific gravity
a relationship between the density of a substance and the density of water density / density of H2O 1.00 g/ml
Energy
ability to do work
matter
all substances that make up our world
Which of the following would not be a physical change?
boiling water for soup burning gasoline in a lawnmower melting gold to make jewelry freezing water to make ice cubes tearing a piece of aluminum foil
density
every substance has a unique one this calculation can help us predict if substances can float in water mass/volume
A liquid has its own volume and shape.
false
A 14 karat gold ring contains gold and other metals. The ring is an example of a(an):
homoenous mixture
In which of the following would the particles move most rapidly?
ice at -20 °C ice at 0 °C boiling water water at 20 °C steam at 110 °C
If an object is dense than a liquid, the object floats when placed in the liquid
less
chemistry
the study of composition, structure, properties, and reactions of matter
Converting Kelvin to Celsius
C = K - 273
Properties of Matter: Physical
Extensive: properties that do depend on how much matter is present Intensity: properties, that do not depend on how much matter is present
In the early studies of chemistry, scientists used properties and changes to help identify compounds. This is still done today. If you were given the following observation about salt water, how would you classify it? "When electricity flows through a flask of salt water, bubbles form in the water. These bubbles, when collected, will burn."
chemical change
Sucrose, better known as table sugar, is represented by the chemical formula C12H22O11. Sucrose would be classified as what type of matter?
compound
Which of the following is not a characteristic of the solid state?
particles are moving very fast has a definite volume particles are close together has a definite shape particles are in fixed positions
