Find study materials for any course. Check these out:
Browse by school
Make your own
To login with Google, please enable popups
To login with Google, please enable popups
Don’t have an account?
To signup with Google, please enable popups
To signup with Google, please enable popups
Sign up withor
Define the following as exact or measured quantities: (a.) 5g (b.) 454g=1lb (c.) 0.82 miles (d.) 12 eggs (e.) 100 cm in 1m
a.) 5g= measured
b.) 454g =1lb = measured
c.) 0.82 mile= measured
d.) 12 eggs= exact
e.) 100 cm in 1 m= exact
What is the value of the following metric prefixes: (a.) deci (b.) kilo (c.) milli (d.) centi
a.) deci = 0.1
b.) kilo = 103
c.) milli = 0.001
d.) centi = 0.01
Round the following measured number to three significant figures: 532,800
Poerform the following calculation of measured numbers (always keep sig figs in mind)
(122.1)(2.9)/ (20.3)(0.06) = 290.714
0.06 only has 1 sig fig, so... the answer is 300
A dog is 97 cm tall. How tall is the dog in inches?
1 in = 2.54 cm
97cm * (1in/2.54cm) = 38 inches
How many pints are in 3.4 liters of liquid?
8 pints = 1 gallon
1 gallon = 3.785 L (this is given)
3.4 L * (1 gal/3.785L) * (8 pints/1 gal)= 《7.2 pints》
A bag of nuts contains 227g. How many ounces (oz) of nuts are in the bag?
1 oz = 28.4 g (this is given)
227g * (1oz/28.4g)= 《7.99 oz》
A sugar-water mixture contains 10.2g of sugar & 185.5g of water. What is the % by mass of water in the solution?
Given: 10.2g of sugar and 185.5g of water
Total grams in mixture: 195.7g
(185.5g water/ 195.7g total) * (x%/100%)= 《94.79%》
A child with a fever has a temp of 38.3ºC. What is the child's temp in ºF?
Tf= 1.8 * 38.3 + 32
The density of a sold A=0.88g/mL. The density of a solid B=2.54g/mL. Which of the two solids will sink when placed in water?
B, because it is heavier gram per 1 mL (it is denser)
An object's mass is 9.55g. Placed in a graduated cylinder w/ 31.3mL of H2O, the water level rises to 39.6mL. Calc dens of obj
Objects mass= 9.55g
Volume of object = Final water level-original water level
Volume= 39.6- 31.3= 8.3 mL
Density = m/v
Density = 9.55g/8.3mL
D= 《1.2 g/mL》
What is the volume in mL of a solution that has a mass of 10.32 g and a density of 1.25 g/mL
《V = 8.26mL》
What is meant by specific gravity of a substance?
The specific gravity of a substance is the relationship between the density of the substance and the density of water.
sp gr= density of subsance/ density of water
What are the standard units of length, mass, volume and temperature in the metric system?
volume = L
temp = ºC
Why is the metric (SI) system called a decimal system of measurement?
Because measurements of each type are related by factors of 10.
Convert centimeters to meters, millimeters to meters, and millimeters to centimeters
100 centimeters= 1 meter
1,000 millimeters = 1 meter
10 millimeters= 1 centimeter
What are the "estimated digits" in the following: a.) 0.82cm b.) 17.25 and c.) 27.63
State the number of significant figures in each: a.) 4.5m b.) 0.0004L c.) 805lb d.) 204.52g e.) 625.000mm f.) 34.80km
What is the equation for converting a Fahrenheit temperature to a Celsius temperature?
What is meant by the specific heat ?
Specific heat is the amount of heat in calories or joules that raises the temperature of 1g of a substance by 1ºC.
What are the units of specific heat?
J/gºC or cal/gºC
How is the caloric value of a food sample determined?
By using a calorimeter. A food sample is placed in a steel container in the calorimeter & water is added to fill a surrounding container. When sample burns, it releases heat that raises the temp of water. Measure increase in water temp.
What property of oil makes it float on water?
It's density. Oil is less dense than water, therefore, it floats.
Why would heating the gas in a hot air balloon make the balloon rise?
The gas in a hot air balloon is less dense than the air around it. When heated, the gas becomes even less dense, and it rises.
What is the difference between density and specific gravity?
Density is the relationship between the mass & volume of a solid/liquid. Specific gravity is the relationship between the density of a solid/liquid & the density of water.
An object has a mass of 18.4g & volume of 11.2mL. Density=? specific gravity=? Will the object sink or float in water?
Density = m/v
Density = 18.4g/11.2mL= 《Density = 1.64 g/mL》
Sp gr= (density of substance)/(density of water)
sp gr= (1.64 g/mL)/ (1.00 g/mL)= 《Sp gr= 1.64 (unitless)》
The object will 《sink》in water, because it is denser than water.
A 15.0g sample of a liquid has a density of 0.875g/mL. Volume in mL=?
0.875 g/mL= 15.0g/?mL
volume = 《17.1mL》
What mass, in grams, of the liquid with density 0.875g/mL is in 34.6mL of the liquid?
0.875g/mL= ?g/ 34.6mL
mass = 《30.3g》
Metal object mass=8.37g, placed in graduated cylinder w/ 20.0mL of H2O, water level rose to 23.1mL. What is the density?
volume= (final water level-initial water level)= 23.1mL-20.0mL= 3.1mL
D= 《2.7g 》
What is the mass of a solution that has a density of 0.775g/mL & a volume of 50.0mL?
What is the volume of a solution that has a specific gravity of 1.2 and a mass of 185g?
Sp gr= density of substance/density of water (1.00g/mL)
Sp gr= density of substance
1.2= density of substance
Convert 25ºC to ºF, 18ºF to ºC, and 45ºC to K.
a.) Tf= 1.8* 25ºC +32= 《77ºF》
b.) Tc= (18ºF-32)/1.8= 《-7.8ºC》
c.) Tk= 45ºC+ 273= 《318K》
A recipe calls for a baking temp of 205ºC. What temp in ºF should be set on the oven?
Tf= 1.8 * 205ºC + 32= 《401ºF》
How many calories are required to raise the temp of 225g of water from 42ºC to 75ºC?
change in temp= 75-42= 33ºC
calories= m * changeintemp * specific heat of H2O (1 cal/ gºC)
calories = 225g * 33ºC * 1cal/gºC
calories = 7,430cal...sig figs... 《7400 cal》
A metal object mass 19g, heated to 96ºC, transferred to container w/ 75g H2O at 18ºC. Final temp is 22ºC, SH of object=?
SH = heat/ (mass*changeintemp)
J = g*changeintemp*SHofwater
J= 19g*ºC*4.184J/gºC= 1,255.2 J
SH= (1255.2J)/ (19g * 74ºC)= 《0.9 J/gºC》
Describe the periodic table
The periodic table contains information about each of the elements. The horizontal rows on the table are "periods" and the vertical rows are "groups." Each group contains elements with similiar properties.
Where are the alkali metals and the halogens located on the periodic table?
The alkali metals are located on the left side of the periodic table. (group 1A)
The halogens are located on the right side of the periodic table. (group 7A)
Why does a Sodium street lamp give off a yellow color, whereas a neon light gives off a red color?
Each element produces a characteristic color if the energy emitted from the element corresponds to the energy of visible light.
Describe the energy levels of electrons in an atom.
The lowest energy level is n=1, and the highest energy level is n=7. Lower energy levels of electrons are usually closer to the nucleus of an atom & higher energy levels of electrons are farther away from the nucleus.
How can you identify an unknown element using a flame test?
Each element produces a characteristic color, so you can identify an unknown element by observing the color of the flame it produces when heated.
Write the electron configuration for each of the following: 1.) lithium 2.) sodium 3.) potassium
1.) Li 1s22s1
2.) Na 1s22s2sp63s1
3.) K 1s22s22p63s23p64s1
Where are the valence electrons in an atom?
Valence electrons are the electrons in the outer shell of an atom that can combine with other atoms to form a molecule.
How are positive and negative ions formed?
A positive ion or cation is formed by removing electrons from an atom or group of atoms until there are fewer electrons than protons. A negative ion/anion is formed when an atom/group of atoms gain electrons until there are more electrons than proton
Why are electrons shared in molecular compounds?
Molecular compounds = covalent
The sharing of electrons allow each atom to attain the equivalent of a full outer shell.
How do the names of molecular compounds differ from the names of ionic compounds?
Ionic compounds end in "-ide". In covalent compounds, look at the prefixes (di-, tri-, etc) & go at the beginning of the second word in the name.
What are polyatomic ions?
Polyatomic ions, aka molecular ions, are charged ions composed of 2 or more atoms covalently bonded or of a metal complex that act as a single unit.
Name the following ionic compounds: 1.) K2S 2.) BaF2 3.) MgO 4.) Na3N 5.) AlCl3 6.) Mg3P2
1.) Potassium sulfide
2.) Barium flouride
3.) Magnesium oxide
4.) Sodium nitride
5.) Aluminum chloride
6.) Magnesium phosphide
Write the formulas of the following molecular (covalent) compounds: 1.) Dinitrogen pentoxide 2.) Silicon tetrachloride
Write the formulas for the following molecular (covalent) compounds: 1.) Phosphorus tribromide 2.) Dinitrogen trisulfide
Write the formulas for the following molecular (covalent) compounds: 1.) Oxygen difluoride 2.) Iodine heptafluoride
Write the formulas for the following ionic compounds: 1.) Potassium carbonate 2.) Sodium nitrate
1.) Potassium: K...carbonate: CO32-
2.) Sodium: Na...nitrate: NO3
Why are burning candles and rusting nails examples of chemical change?
In burning candles & rusting nails, the substance is converted to one or more new substances with different properties.
What is included in a chemical reaction?
Reactants, products, coefficients
What are the different types of evidence of a chemical reaction?
Change in color, heat produced, bubbles
Which energy level is the lowest?
What sublevel is the highest energy out of 3d, 3s, or 3p?
Ag-107 has an isotopic mass of 106.9amu & % abundance of 71.84, Ag-109 has mass of 108.9amu & %abundance 28.15%. Atomic mass?
Ag-107= 106.9 amu & %abundance 71.84%
Ag-109= 108.9 amu & %abundance 28.15%
106.9 * (71.84/100) = 76.80
108.9 * (28.15/100) = 30.66
76.80 + 30.66 = 《107.46 amu》
When liquid water at 0ºC freezes, is energy lost or gained by the water? Why?
At 0ºC, heat is lost
What is meant by the simplest formula of a compound?
The lowest whole-number ratio of the atoms in the formula.
How does a hydrate differ from an anhydrate?
a hydrate is an ionic compound that is combined with a specific number of water molecules. An anhydrate is the remaining ionic compound when all of the water is removed by heating.
What happens when a hydrate is heated?
When a hydrate is heated, water molecules are removed.
A hydrate of CoCl2, with mass of 6.00g is heated strongly. After cooling, the mass of the anhydrate is 3.27g. See next slide
How many grams of H2O were lost from the hydrate? What is the % water in the hydrate?
6.00g - 3.27g = 《2.73 grams if H2O were lost.》
(2.73/6.00) = (X/100)=== 273/6= 《45.5%》
What is the formula of the CoCl2 hydrate?
Molar mass of H2O = 18.0g/mole
Molar mass of CoCl2= 129.83g/mole
2.73gH2O * (1 mole/18.0g H2O)= 0.152 moles H2O
3.27g CoCl2/129.83g/mole CoCl2= 0.025
0.152 moles H2O/ 0.025= 6
《CoCl2 * 6H2O》
Calculate the simplest formula for 1.) 0.200mole of Al & 0.600mole of Cl 2.) 0.080 mole of Ba, 0.080 mole S, & 0.320mole O
1.) 0.200mole Al/ 0.200= 1 mole Al
0.600mole Cl/ 0.200= 3 moles Cl
2.) 0.080 mole Ba/0.080= 1 mole Ba
0.080 mole S/0.080= 1 mole S
0.320 mole O/0.080= 4 moles O
Why is an airplane pressurized?
So the people on the airplane can breathe sufficient oxygen.
Why does a scuba diver need increased gas pressure in the tank?
Because the pressure of their bodies increases as they dive deeper.
How does temperature affect the kinetic energy of gas molecules?
When the temperature increases, the kinetic energy of gas molecules increases.
A balloon is filled with 652mL of He at a pressure of 1.00atm. Pressure decreases to 738mmHg, T & n constant, new volume=?
V1= 652mL V2= ?mL
P1= 1.00atm P2= 738mmHg= 0.971atm
A sample of neon (Ne) gas occupies 75.0mL at 25ºC. What is the new volume if temp decreases to -12ºC, w/ P & n constant?
V1= 75.0mL V2=?
T1=25ºC= 298K T2= -12ºC= 261K
(75.0mL/298K) = (V2/261K)
What factors increase the rate of a chemical reaction?
Temperature, concentration of reactants, and catalysts.
When is equilibrium established in a reversible reaction?
Equilibrium is established in a reversible reaction when the rate of the forward reaction becomes equal to the rate of the reverse reaction.
How does a system at equilibrium respond to the addition of more reactant?
Adding more reactants will shift the forward reaction in the direction of the products.
How does a system at equilibrium respond to the addition of more product?
Adding more product will shift the reverse reaction in the direction of the reactants.
How is the pH of a solution related to the [H3O+]?
If H3O is greater than OH , pH is acidic
If H3O is the same as OH, pH is neutral
If H3O is less than the OH, pH is basic
Is a solution with a pH of 12.0 acidic or basic?
Is a solution with a pH of 2.0 acidic or basic?
What is a buffer?
An agent that maintains the pH of a solution by reacting with and neutralizing small amounts of acids or bases.
If you add acid or base to water, how will the pH change?
pH will change substantially
If you add acid or base to a buffer, how will the pH change?
pH will only change a little
A sample of 0.0084mole HCl is dissolved in water to make 1500mL solution. Calculate the molarity of the HCl solution and pH.
1500mL= 1.5 L
(0.0084mole HCl/1.5L)= (? mole HCl/1L)
?= 0.0056 M HCl
5.6 * 10-3
What is neutralization?
When the amount of H+ is equal to the amount of OH-
What is a titration?
A technique where a solution of known concentration is used to determine the concentration of an unknown solution.
What is the function of an indicator in a titration?
Let's you know when the titration is finished.
Sign up for free and study better.
Get started today!