Ch. 1 Flashcards
What is “matter”?
The physical matter of the universe. It has mass, occupies space, has properties that distinguish it, and is made up of different combinations of only a relatively small # of elements. The fundamental building block of matter is atoms.
How many significant figures should be listed in the answer when the calculation performed involves either multiplication or division?
The answer should have the same # of significant figures as the the least significant # used in the calculation. E.g. 3.45/1.2 = 2.875 = 2.9 (because 1.2 has only 2 sf while 3.45 has 3, so the answer should have 2 sf).
How many significant figures should be listed in the answer when the calculation performed involves either addition or subtraction?
The answer should have the same # of decimal places as the measurement with the fewest decimal places used in the calculation (i.e. sf doesn’t matter here, but decimal places do!). 1.234 + 2.3 = 1.534 = 1.5 (because 2.3 occupies the tenths place while 1.234 occupies the thousandths place).
Define “precision”
How close several measurements are to each other (“good grouping”, but not necessarily in the right place/accurate).
Define “accuracy”
How close measurements are to the TRUE value.
What is the calculation for density?
d= m/v
Density = mass/volume
Often measured as g/cm^3 or g/mL.
What is “volume”?
An amount of space a substance takes up. Measured by lengthlengthlength, or length^3.
Commonly measured in cm^3 or “cc” which stands for “centimeters cubed”.
What is the difference between a cc and a mL?
Both are equivalent and used to measure volume but cc’s are usually used to measure solids while mL’s are used to measure fluids.
What is “density”?
The amount of mass per unit.
(Density = mass/volume)
Often measured as g/cm^3 or g/mL.
What is an atom?
Atoms make up matter, are made of subatomic particles, and when combined form molecules.
What is an element?
A substance made purely of one type of atom.
What is the difference between a solid, a liquid, and a gas?
Solid: Has a definite shape AND volume.
Liquid: Has a definite volume. Takes the shape of the container it is in.
Gas: Compressible (no definite volume) and takes the shape of the container it is in.
What is a pure substance?
A classification of matter.
Composition doesn’t vary from sample to sample.
What is an element?
A classification of matter.
Cannot be decomposed into simpler substances. Organized into periodic table of elements.
What is a compound?
A classification of matter.
A combination of two or more ELEMENTS into distinct (unchanging, definite) proportions. E.g. CO2 will always be 1 carbon and 2 oxygen.
What is a molecule?
A classification of matter.
Two or more ATOMS.
(All compounds are molecules, but not all molecules are compounds!)
What is a mixture?
Two or more components that do not have definite proportions E.g. saltwater or a bag of mixed nuts - you know it’s a combination, but saltwater could be used to describe 1 tsp salt to 1mL of water or 1 tsp salt to 1 L of water).
What are the two types of mixtures and how are they defined?
Mixtures are two or more components that do not have definite proportions.
Homogenous Mixtures - Are uniform throughout and often called solutions.
Heterogenous Mixtures - Vary through the sample. Not really a common thing in chemistry. E.g. is a bag of nuts or a wax candle with flower pieces inside. You can pick out the parts you want, so it’s not consistent throughout.
What is a solution?
A solution is a homogenous mixtures (the two terms are interchangeable). It is a mixture of of two or more components that do not have definite proportions.
What is the difference between physical and chemical properties of matter?
Physical properties are measurable without changing the identity of the compound/substance. E.g. color, odor, melting point, boiling point (both involve changing state only), and density.
Chemical properties - describe chemical reactivity of a substance, and in order to measure these properties, we have to change the substance into another substance. E.g. Burning something requires oxygen to create a chemical reaction and the loss of electrons. Iron rusting is another example.
How are physical changes different from chemical changes?
Physical changes alter the physical appearance of something but do not change its chemical composition (e.g. boiling/melting is a state change, but the chemical bonds are not broken, therefore the compounds/molecules/substance remains the same).
Chemical changes are REACTIONS, they transform the substance into a NEW substance (e.g. rusting).
What are intensive properties?
(Inherent) properties - i.e. They do not depend on the amount of a substance in order to be expressed. They can, to some extent, be used to identify the substance. E.g. include boiling point, melting point, and density.
What are extensive properties?
Properties that depend upon the amount o a substance and cannot really be used to identify it (e.g. mass, heat evolved/required).
What is the formula for converting from degrees Fahrenheit to degrees Celsius?
C = 5/9 (F-32)
What is the formula for converting from degrees Celsius to Kelvin?
K = C + 273.15
At what temperature does water freeze in Fahrenheit, Celsius, and Kelvin?
32 F
0 C
273.15 K
At what temperature does water boil in Fahrenheit, Celsius, and Kelvin?
212F
100C
373.15 K
What is “room temperature” in Fahrenheit, Celsius, and Kelvin?
75 F
25 C
298.15 K
What is average “body temperature” in Fahrenheit, Celsius, and Kelvin?
98.6 F
37 C
310.15 K
What is the Atomic Theory of Matter?
- Elements are composed of atoms
- Atoms of an element are identical to one another but different from atoms of other elements
- Atoms of one element cannot be changed into atoms of another element (by any chemical means).
- Atoms cannot be created or destroyed in reactions (Law of Conservation of mass/matter)
- Compounds are combinations of two or more different types of elements; must have the same relative # and type of atoms (Law of Constant Composition).
Who invented the Atomic Theory of Matter?
John Dalton
What is the Law of Conservation of Mass/Matter?
Atoms cannot be created or destroyed in reactions
What is the Law of Constant Composition?
Compounds are combinations of two or more different types of elements; must have the same relative number and type of atoms.
What is the Law of Multiple Proportions?
Elements that combine in different ways to form more than one compound must do so in ratios of whole numbers. E.g. N2O, NO, NO2. (John Dalton)
Which elements are found in nature as diatomic molecules?
N(itrogen)ever H(ydrogen)ave F(luorine)ear O(xygen)f I(odine)ce C(hlorine)old B(romine)eer.
Of the elements typically found as diatomic molecules in nature, which occur as gases as compared to liquids or solids?
Gases: Nitrogen, Hydrogen, Fluorine, Oxygen, Chlorine
Liquid: Bromine
Solid: Iodine
Which elements tend to lose electrons versus gain them?
Metals tend to lose electrons and become cationic, while non-metals tend to gain electrons and become anionic.
What comes first in writing an ionic compound’s chemical formula?
The cation.
Where are Alkaline Earth Metals located in the periodic table of elements?
Group 2A.
Where are Alkali Metals located in the periodic table of elements?
Group 1A (except Hydrogen, which is not an Alkali Metal).
Where are Noble/Rare Gases located in the Periodic Table of Elements?
Group 8A.
Where are Halogens located in the Periodic Table of Elements?
Group 7A.
Where are Chalcogens located on the Periodic Table of Elements?
Group 6A.
What are columns called on the Periodic Table of Elements?
Groups
What are rows called on the Periodic Table of Elements?
Periods
Do groups or periods determine similar characteristics/behavior between elements?
Groups
Which elements on the Periodic Table of Elements are non-metals?
Groups 7A and 8A (except At) and C, N, O, P, S, and Se.
Which elements are Metalloids on the Periodic Table of Elements and what are their characteristics?
Located between the transition metals and the non-metals: B, Si, Ge, As, Sb, Te, At.
They share properties of metals and non-metals. and are sometimes called “semiconductors”.
Which elements are metals on the Periodic Table of Elements, and what are their characteristics?
Groups 1A (except H) are Alkali metals, 2A are Alkaline Earth Metals, the middle section is Transition metals, and the disconnected rows below the table are Inner Transition metals (sometimes known as Rare Earth Metals).
They are conductive (conduct electricity), have luster, are ductile (can be made into wire), malleable, and solid at room temperature (with the exception of Mercury Hg).
What are the four types of diagrams for visually depicting chemical compositions?
Structural formula, perspective drawing, ball and stick model, space-filling model.
What is the difference between a chemical formula and an empirical formula?
Chemical formulas list the exact # of atoms of each element required to form the compound, whereas empirical formulas list the relative #’s/simplified proportions. E.g. Chemical formula H2O2 would become empirical formula HO.
Do metals tend to become cationic, anionic, or unpredictably lose/gain ions?
Cationic
Do non-metals tend to become cationic, anionic, or unpredictably lose/gain ions?
Anionic.
Are cations positively or negatively charged?
Positive.
Hint: “cat”ion = “paws”itively charged.
What type of compound is this, and why?
NaCl
Ionic. It’s a binary compound (2 elements) consisting of a metal and a non-metal.
What type of compound is this, and why?
CO2
Molecular. It is comprised of nonmetals.
What is the general rule for determining if a compound is molecular or ionic?
Binary compounds with a metal and a non metal are ionic. Molecular compounds are those comprised of only nonmetals.
What naming convention (nomenclature rule) applies to monoatomic cations, and which elements does this nomenclature rule apply to?
Cations from metal ions (monoatomic cations) that can form only one possible cation have the same name as the metal. E.g. Mg2+ is magnesium, or a magnesium ion, Na+ is sodium, or a sodium ion.
Groups: 1A, 2A, Al3+, Ag+, Zn2+
What naming convention (nomenclature rule) applies to transitional metals?
Because the charges of transitional metals are inconsistent and cannot be predicted by looking at the table, there is not a standard naming convention other than you MUST indicate the charge when listing the ion (because otherwise it is not implied).
E.g. Fe2+ is an Iron (II) ion, Fe3+ is an Iron (III) ion.
What are the (new and old) ionic compound names for Fe2+?
Iron (II) ion and ferrous ion.
What are the (new and old) ionic compound names for Fe3+?
Iron (III) ion and ferric ion.
What are the (new and old) ionic compound names for Cu+1?
Copper (I) and cuprous ion.
What are the (new and old) ionic compound names for Cu+2?
Copper (II) and cupric ion.
What are the (new and old) ionic compound names for Hg+1?
Mercury (I) and Mercurous ion.
What are the (new and old) ionic compound names for Hg+2?
Mercury (II) and Mercuric ion.
What are the common charges found on Cu, Fe, and Hg, and to which are the designation of -rous and -ric endings ascribed to?
Cu+1 (cuprous), Cu+1 (cupric)
Fe+2 (ferrous), Cu+3 (ferric)
Hg+1 (mercurous), Hg+2 (mercuric)
Which transitional metals do ionic compound nomenclature rules not apply to?
silver (Ag) and zinc (Zn) - because they are monoatomic cations.
Polyatomic/complex cations to memorize:
NH4+ = Ammonium Ion H3O+ = Hydronium Ion
What naming convention (nomenclature rule) applies to monoatomic anions?
The names end in -ide.
E.g. O2 = oxide anion; F- is Fluoride Ion
List the polyatomic anions with names ending in -ide to be memorized:
CN- = Cyanide OH- = Hydroxide O2^2- = Peroxide
What are the chemical formulas for Cyanide, Hydroxide, and Peroxide?
Cyanide = CN- Hydroxide = OH- Peroxide = O2^2- (O subscript 2, exponent 2, negative charge)
What is the chemical formula for carbonate?
…
What is the chemical formula for sulfate?
…
What is the chemical formula for nitrate?
…
What is the chemical formula for phosphate?
…
What is the chemical formula for perchlorate?
…
What are the names and formulas for the oxyanions we’re supposed to memorize?
Carbonate: CO3 Chlorate: ClO3 Nitrate: NO3 Sulfate: SO4 Phosphate: PO4
All the “-ite”’s have one less oxygen.
There is no carbonite! Notice: CO2 is Carbon Dioxide Chlorite: ClO2 Nitrite: NO2 Sulfite: SO3 Phosphite: PO3
Chlorine also has +1 oxygen (perchlorate ClO4) and -2 oxygen (hypochlorite ClO).
You can calculate the charges… they are not neutral.
What is HCO3- colloquially known as?
Bicarbonate.
What is HPO42-?
Hydrogen phosphate
What is H2PO40
Dihydrogen phosphate
