Inorganic Chemistry C3- Activity 2 Flashcards
What are the five basic types of chemical reactions?
- combination
- decomposition
- single-displacement
- double-replacement
- combustion
True or false
Identifying a reaction as one of these types does not preclude it from also being an oxidation-reduction (redox) reaction.
TRUE
for example: many combination reactions can also be classified as a redox reactions.
What is combination reaction?
also known as a synthesis reaction, in which two or more substances or elements combine to form a single new substance or compound.
What is the genera reaction of a combination reaction?
A + B –> AB
True or false
Combination reaction can’t also be classified as a redox reaction due to the changes in oxidation states.
FALSE
Sodium goes from a 0 to +1 oxidation state while chlorine goes from a 0 to a -1 oxidation state.
Notice:
In order to write and balance the equation correctly, it is important to remember…
all seven elements that exist in nature as diatomic molecules (H2, N2, O2, F2, Cl2, Br2, and I2.
True or false
Metals and nonmetals both don’t react readily with oxygen under most conditions.
False
One sort of combination reaction that occurs frequently is the reaction of an element with oxygen to form an oxide.
Ex. Magnesium reacts rapidly and dramatically when ignited, combining with oxygen from the air to produce a fine powder of magnesium oxide.
What is decomposition reaction?
Decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances.
What is the general form of a decomposition reaction?
AB –> A + B
True or false
Most decomposition reactions require an input of energy in the form of heat, light, or electricity.
True
Binary compounds are composed of what
Binary compounds are composed of just two elements.
Predict the product and balance the reaction of the decomposition of mercury (II) oxide
Mercury (II) oxide is a red solid that decomposes when heated to produce mercury and oxygen gas
thus,
2HgO (s) –> 2Hg (l) + O2 (g)
Yes or no
Can a reaction be considered to be a decomposition reaction even when one or more of the products is still a compound?
Yes.
Ex.
1. A metal carbonate decomposes into a metal oxide and carbon dioxide gas
2. Calcium carbonate decomposes into calcium oxide and carbon dioxide
CaCO3(s) –> CaO(s) + CO2(g)
Predict the product of the decomposition reaction of sodium hydroxide
Sodium hydroxide decomposes to produce sodium oxide and water
2NaOH (s) –> Na2O (s) + H2O(g)
What is single-replacement reaction?
a reaction in which one element replaces a similar element in a compound
What are the other terms for single-replacement reaction?
- Singe-displacement reaction
- Substitution reaction
What is the general form of a single-replacement reaction?
A + BC –> AC + B
True or false
When the element that is doing the replacing is a metal, it must replace another nonmetal in a compound, and the general equation becomes:
Y + XZ –> XY + Z
FALSE
When the element that is doing the replacing is a nonmetal, it must replace another nonmetal in a compound, and the general equation becomes:
Y + XZ –> XY + Z
What is more reactive magnesium or copper?
Magnesium
When a strip of magnesium metal is placed in an aqueous solution of copper (II) nitrate, it replaces the copper. What are the products of the reaction?
Magnesium nitrate and solid copper metal
Mg(s) + Cu(NO3)2(aq) –> Mg(NO3)2(aq) + Cu(s)
True or false
Metals react easily with acids, and, when they do so, one of the products of the reaction is hydrogen gas
TRUE
Ex.
Zinc reacts with hydrochloric acid to produce aqueous zinc chloride and hydrogen
Zn (s) + 2HCl (aq) –> ZnCl2 (a) + H2(g)
What is double-replacement reaction?
Also known as double-displacement is a reaction in which the positive and negative ions of two ionic compounds exchange places to form two new compounds.
What is the general form of a double-replacement reaction?
AB + CD –> AD + CB
Expound the general form of the double-replacement reaction
AB + CD –> AD + CB
AB + CD –> AD + CB
A and C are positively-charged cations, while B and D are negatively-charged anions.
True or false
Double-replacement reactions generally occur between substances in aqueous solution.
TRUE
What are the common occurring products of the double-replacement reaction?
- Solid precipitate
- Gas
- Molecular compound (e.g., water)
How does a precipitate forms in a double-replacement reaction?
a precipitate forms in a double-replacement reaction when the cations from one of the reactants combine with the anions from the other reactant to form an insoluble ionic compound.
Predict the products when aqueous solutions of potassium iodide and lead (II) nitrate are mixed.
2KI (aq) + Pb(NO3)2 (aq) –> 2KNO3(aq) + PbI2 (s)
What is combustion reaction?
Combustion reaction is a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat.
What reactant must be involved in combustion reactions?
O2
Show the balanced chemical equation of the combustion of hydrogen gas
2H2(g) + O2(g) –> 2H2O (g)
NOTICE: THIS REACTION ALSO QUALIFIES AS A COMBINATION REACTION
True or false
Many combustion reactions occur with a hydrocarbon, which products of the combustion reaction are always carbon monoxide and water
FALSE
they always produce carbon dioxide and water
Show the balanced equation of the combustion reaction of propane
C3H8 (g) + 5O2(g) –> 3CO3(g) + 4H2O (g)
It is a process in which a substance is changed into one or more new substances
Chemical reaction
It uses chemical symbols to show what happens during a chemical reaction. It is also considered as the Chemist’s shorthand description of a reaction.
Chemical equation
Read correctly the equation below
2H2 + O2 –> 2H2O
Molecular hydrogen reacts with molecular oxygen
to yield water
2 moles of hydrogen molecules react with 1 mole of
oxygen molecules to produce 2 moles of water molecules
What are reactants
starting materials in a chemical reaction
what is product
substance formed as a result of a chemical reaction
Predict the products of the reaction when potassium bromide and silver nitrate react in an aqueous environment
a solid silver bromide is formed
KBr (aq) + AgNO3 (a) –> KNO3 (a) + AgBr (s)
It is the quantitative study of reactants and products in a chemical reaction
Stoichiometry
What is mole method?
The stoichiometric coefficients in a chemical equation can be interpreted as the number of moles of each substance.
True or false
The maximum amount of product formed depends on how much of this reactant was originally present.
TRUE
What is a limiting reagent?
The maximum amount of product formed depends on how much of this reactant was originally present.
These are the reactants present in quantities greater than necessary to react with the quantity of the limiting reagent.
Excess reagents
unit of molality
mol of solute/kg of solvent
unit of molarity
mol/L
The amount of limiting reagent at the start of a reaction determines the ___ of the reaction, that is, the amount of product that would result if all the limiting reagent reacted.
Theoretical yield
What is an actual yield?
The amount of product actually obtained from a reaction, and is almost less than the theoretical yield.
It is the maximum obtainable yield of product actually obtained from a reaction and is almost less than the theoretical yield.
theoretical yield
What is the mathematical formula of %yield?
%yield= actual yield/ theoretical yield *100%
Provide the volume percent formula
Volume percent= (volume of solute/ volume of solution) x 100
1 amu is equal to how many grams?
1.66x10^-24 grams
Why do chemists use chemical formulas?
To express the composition of molecules and ionic compounds in terms of chemical symbols and also the ratios in which the atoms are combined.
It shows the exact number of atoms of each element in the smallest unit of a substance.
Molecular formula
What is an allotrope?
One of two or more distinct forms of an element.
Ex. two allotropic forms of the element carbon- diamond and graphite- are dramatically different not only in properties but also in their relative cost.
What is freezing point depression?
It is the freezing point of the pure solvent minus the freezing point of the solution.
It refers to the actual number of particles in solution after dissociation to the number of formula units initially dissolved in solution
van’t Hoff factor
It is defined as the vapor pressure of the solvent over a solution given by the product of the vapor pressure of the pure solvent and the mole fraction of the solvent in the solution.
Raoult’s Law
Raoult’s Law is represented as
The vapor pressure of the solution is the product of the mole fraction of the solvent multiplied by the vapor pressure of the vapor pressure of the solvent.
Psoln= X solvent * P solvent
True or false
If you add a nonvolatile solute to a solvent, the vapor pressure of the solution would be less than the vapor pressure of the pure solvent.
TRUE
1 atomic mass unit (amu) is equal to how many dalton (Da)
1 amu = 1 Da
amu or Da is defined as
1/12 of the mass of one neutral C-12 atom
Avogadro’s number is equal to
6.022x10^23 atoms/molecules/ions
What is the formula for acquiring the number of moles?
n=mass/molar mass
FORMULA: %(w/w)
%w/w=wt solute(g)/wt sample(g) * 100
FORMULA: parts per thousand, ppt
ppt(w/w)= wt solute(g)/wt sample(g) * 10^6
ppt(w/w)= wt solute(g)/ wt solution(g) * 10^6
FORMULA: parts per billion (w/w) (ppb)
ppb (w/w)=wt solute(g)/ wt sample (g) * 10^9
ppb (w/w)=wt solute(g)/ wt solution (g) * 10^9
FORMULA: %(w/v)
%(w/v)= wt solute(g)/vol sample(mL) * 100
%(w/v)= wt solute(g)/vol solution(mL) * 100
FORMULA: ppm (w/v)
pm (w/v)= wt solute (g)/ vol sample (mL) * 10^6
pm (w/v)= wt solute (g)/ vol solution (mL) * 10^6
FORMULA: parts per billion (w/v) (ppb)
ppb (w/v)= wt solute(g)/vol sample (mL) * 10^9
ppb (w/v)= wt solute(g)/vol solution (mL) * 10^9
These are attractive forces between molecules, which are responsible for the nonideal behavior of gases and exert even more influence in the condensed phases of matter- liquids and solids.
Intermolecular forces
True or false
At a sufficiently low temperature, the molecules no longer have enough energy to break away from the attraction of neighboring molecules.
TRUE
It is a type of force that holds atoms together in a molecule, which also stabilize individual molecules.
Intramolecular forces
What is the difference between intermolecular and intramolecular forces?
Intermolecular forces are primarily responsible for the bulk properties of matter (e. g., melting point and boiling point) while intramolecular forces hold atoms together in a molecule. Generally, intermolecular forces are much weaker than intramolecular forces.
True or false
The boiling points of substances often reflect the weakness of the intermolecular forces operating among the molecules.
False
The boiling points of substances often reflect the strength of the intermolecular forces operating among the molecules.
NOTE: enough energy must be supplied to overcome the attractive forces among molecules before they can enter the vapor phase.
What are the different types of intermolecular forces?
- Dipole-dipole
- Dipole-induced dipole
- Dispersion forces/ van der Waals forces
True or false
Ions and dipoles are attracted to one another by electrostatic forces called van der Waals forces.
False
Ions and dipoles are attracted to one another by electrostatic forces called ion-diple forces.
True or false
Hydrogen bonding is a particularly strong type of dipole-dipole interaction as only a few elements can participate in hydrogen bond formation and it is treated as a separate category.
TRUE
These are attractive forces between polar molecules, that is, between molecules that possess dipole moments.
Dipole-dipole forces
True or false
The larger the dipole moment, the greater the force. The dipole-dipole forces’ origin is electrostatic, which can be understood in Coulomb’s law.
TRUE
It can also be explained by Coulomb’s law, which can also attract an ion (either a cation or anion) and a polar molecule to each other.
Ion-dipole forces
True or false
The strength of the interaction depends on the charge and size of the ion and on the magnitude of the dipole moment and size of the molecule.
TRUE
True or false
The charges on cations are less concentrated because cations are usually smaller than anions. Thus, a cation interacts more strongly with dipoles than does an anion having a charge of the same magnitude.
FALSE
The charges on cations are more concentrated because cations are usually smaller than anions. Thus, a cation interacts more strongly with dipoles than does an anion having a charge of the same magnitude.
It refers to the separation of positive and negative charges in the atom (or nonpolar molecule) due to the proximity of an ion or a polar molecule.
induced dipole interaction
True or false
The attractive interaction between an ion and the induced dipole is called ion-induced dipole interaction, and the attractive interaction between a polar molecule and the induced dipole is called dipole-induced dipole interaction.
TRUE
It allows gases containing atoms or nonpolar molecules (e.g., He and N2) to condense.
Polarizability
