Chem 1010 -Lab PALM
Determine SF in Multiplication/ Division by
using the least amount of Significant Figures. eg. 3.12(3sf)x2.4(2sf)=7.488=7.5 (round/ 2 sf)
Determine decimal places in Adding/ Subtracting by
using the lowest amount of decimal places. eg. 2.045+34.1=36.145 = 36.1 (1 dec. place)
The freezing point of water is
0C or 32F or 273K
How many calories are required to raise the temperature of 225g of water from 42C to 75C?
1 cal= heat needed to raise the temperature of 1 g of water. 225g water x 33C = 7,425 cal
1 kilometer = 10 hectometers = 100 dekameters = 1000 meters = 10 000 decimeters = 100 000 centimeters = 1 000 000 millimeters
1 milliliter = 0.1 centiliters = 0.01 deciliters = 0.001 liters = 0.000 1 dekaliters= 0.000 01 hectoliters = 0.000 001 kiloliters
Rules for Rounding off
1. If the first digit to be dropped is 4 or less, drop the following #s 2. If the first digit to be dropped is 5 or greater, increase by 1
Fever
100.4-104.0
The boiling point of water is
100C or 212F or 373K
Hyperthermia
105.8-107.6
Normal room temperature
22C or 72F
Normal body temperature
37.0C or 96.8-98.6F or 310K
How many SF for the following? 4.5m 0.0004L 805lb 204.52g 625.000mm 34.80cm
4.5m - 2 0.0004L -4 805lb -3 204.52g -5 625.000mm -3 34.80cm -4
An object made of aluminum has a mass of 8.37g. When it was placed in a graduated cylinder containing 20.0 mL of water, the water level rose to 23.1 mL. Calculate the density and the specific gravity of the object.
8.37g/ 3.1ml= 2.7g/mL 2.7g/mL/ 1.00 g/mL= 2.7
Hypothermia
93.2-95.0
A metal object with a mass of 19g is heated to 96C, then transferred to a calorimeter containg 75g of water at 18C. The water and metal object reach a final temperature of 22C. A. What is the specific heat of this metal object? B. What is the metal?
A. 300/19 x 74 = 300/1406 = 0.21 cal/g C 75 x 4 x 1 = 300 cal (heat gained) B. Aluminum
Where are the alkali metals and the halogens located on the periodic table?
Alkali metals are on column one (H, Li, Na, etc...) Halogens are column 7 ( F, Cl, etc...)
Metalloids (semi-metals)
B, Si, Ge, As, Sb, Te
Why did you need to transfer the metal quickly from the hot water bath to the water in the styrofoam cup calorimeter?
Because the minimal amount of heat is lost from the metal into the air & once the metal is removed. Its tenperature will begin to be near room temp. The lesser energy is release in the air the quicker its transferred and more energy is released in the water.
A neural atom has a mass # of 80 and 45 neutrons. Write its complete nuclear symbol. (protons + neutrons= Mass #)
Bromine = Br
Volume
Liter (L) - Metric Cubic meter (m3) - SI
Metal or Nonmetal
Ca C Fe F Cu S Na
Temperature
Celsius (C) - Metric Kelvin (K) - SI
What is the difference between density and specific gravity?
Density is defined as mass per unit volume. It has SI unit Kg. Specific gravity is the ratio of a material's density with that of water at 4C.
Why would heating the gas in an air balloon make the balloon rise?
When the gas(air) in a hot air balloon is heated it becomes less dense.
On the following list of elements, circle the symbols of the transition elements and underline the symbols of the halogens
F, Fe, Cl,, Ni, Ag, Br, Cu, Mg
Mass
Gram (g) - Metric Kilogram (kg) - SI
Alkali metals
Group 1A except H
Alkaline earth metals
Group 2A
Hallogens
Group 7A and H
Noble gases
Group 8A
How does a graph help us interpret scientific data?
It allows us to see a change in the data which can use to predict a trend or track other noteworthy details.
Describe the periodic table
It is a tabular arrangement of the chemical elements organized by the atomic number ( number of protons in the nucleus), electron configurations and recurring chemical properties. Elements, chemical symbol, in each box. The table consists of 18 columns and 7 rows and a double row of elements below it. 4 blocks are s,p,d, and f.
Potassium Sulfur Nitrogen Magnesium Copper Sodium Phosphorus Iron Chlorine Silver
K S N Mg Cu Na P Fe Cl Ag
Name Abbr./ Property for these Units. Liter, centimeter, kilometer, milligram
L (volume), cm(length), km(length), mg(mass)
Length
Meter (m) - Metric Meter (m) - SI
An atom has 37 protons and 45 neutrons. What is the nuclear symbol?
Rubidium = Rb
Time
Second (s) - Metric Second (s) - SI
Write the formula for calculating specific heat and both values for the specific heat of water in (cal/g Celsius and J/Celsius
Sp heat= Amount of heat (cal or J)/ Mass (g) x change in temperature ^T(Celsius)
What is meanth by the term specific heat?
Specific heat is the amount of heat energy required to raise the temperature of a body per unit of mass
Convert Fahrenheit to Celsius
Temperature C= (TF) - 32 degrees / 1.8
Convert Celsius to Fahrenheit
Temperature F= 1.8 (TC) +32 degrees (adjusts freezing point)
Kelvin Temperature
Temperature K= (TC) +273
How is the caloric value (kcal/g) of a food sample determined?
The # of calories in a food is deternined by using an apparatus called a calorimeter. A sample is placed in a steel container within the calorimeter & water is added to fill a surrounding chamber.
Water has one of the largest specific heats of any substance. Why is this important for the human body?
The body's water needs to be able to withstand high & cold enviornments.
You are cooking spaghetti in wter you have salted with NaCl. You notice that when the water boils over, it causes the flame of the gas burner to turn bright orange. How would you explain the appearance of a color in the flame?
The electron in the sodium will absorb energy and be promoted to new excited levels, when the electrons fall back to their natural state they will release characteristic energies with a frequency in the visible spectrum. Sodium gives a more yellow glame but as water spils over its a brighter yellow orange color.
Why is a measured amount of water needed to determine the specific heat of a metal object?
The heat energy absorbed or released by the water is dependent on the mass of the water. q= m x c x delta T The equation tells you that you need a mass, sp ht, and change in T to figure out the sp ht of the metal.
Why do some elements produce colorful flames?
The specific build of an element causes it to reflect particular wavelength of light. Different elements absorb different wavelength (different color).
What are the energy levels of electrons?
They are the total number of energy levels in the atom. The period the element is in equal to the total number of energy levels.
What is the color of a neon light ( a plain, colorless, uncoated tube containing only neon gas)?
They can contain a mixture of neon and other gases. Pure neon gives of a redish - orange light. The gases present in the light determine its color.
What is the volume of a solution that has a specific gravity of 1.2 and a mass of 185g?
V= 185g/1.2 V= 150mL
What property of oil makes it float on water?
Water is denser than oil
How do you convert larger unit to smaller unit?
When converting from a larger unit to a smaller unit there will be more of them, so multiply by the conversion factor; eg km to m: there a 1000m in 1 km, so multiply by 1000 so 2.4 km = 2.4 x 1000 m = 2400 m km = 2.4 km
How do you convert from a smaller unit to a larger?
When converting from a smaller unit to a larger unit there will be less of them so divide by the conversion factor; eg m to km: there are 1000m in 1 km so divide by 1000, so 2400 m = 2400 ÷ 1000 km = 2.4 km
Metric Units
are all multiples of ten (or a hundred, or one-tenth, etc) of each other. You can convert between the various different sizes by merely moving the decimal point the correct number of places.
Exact Numbers
are numbers obtaine by counting items or from a definition that compares two units in the smae measuring system. eg. 8 doughnuts, 1ft-12in., 1 qt-4cups, 1 lb -16oz., 1L-1000 mL, 1 m -100cm, 1kg-1000g (No need for a measuring device.)
King Henry Doesn't [Usually] Drink Chocolate Milk
kilo- hecto- deka- [unit] deci- centi- milli-
Why does a sodium street lamp give off a different color light than a neon light?
neon will give a red light whille sodium a yellow light. When atoms are excited, electrons are promoted beyond the outer shell and the atom ionises. When the electron falles back again, the energy is re-emmitted as light. The wavelength of the light depends on the element.