Science Final #2
Write the formula for sample mass.
# of moles * molar mass
Define atomic #.
# of p
Define mass #.
# of p+n
What did Rutherford discover?
+ nucleus
Define proton.
+ particle in the nucleus
Define electron.
- particle outside the nucleus
if the H₃O⁺ concentration is 10,000, what is the pH?
-4
Write the rules for chemical formulas.
-ide, prefixes for nm + nm, no prefixes for m + nm, 1st mono silent
Write the formula for pH.
-log[H₃O⁺]
A strong acid has a pH closer to __.
1
How many valence electrons does Na have?
1
Elements have only __ kind of ____.
1 / atom
Write the oxidation number for each family.
1+, 2+, 3+, 4+-, 3-, 2-, 1-, 0
How many valence electrons for families - 1,2,13,14,15,16,17,18
1,2,3,4,5,6,7,8
The molar mass of NaBr is what?
102.9 g/mole
If the mass of Na is 23, how many neutrons does it have?
12
A strong base has a pH closer to __.
14
Determine the average atomic mass for these isotopes. 95% N-14, 3% N-15, and 2% N-16.
14.07 amu
What is the mass of a molecule of CCl₄?
153.82 amu
Balance - Pb(OH)₂ + HCl → H₂O + PbCl₂
1Pb(OH)₂ + 2HCl → 2H₂O + 1PbCl₂
How many valence electrons does Be have?
2
If the H₃O⁺ concentration is 10⁻², what is the pH?
2
Write the electron configuration for F.
2,7
Write the electron configuration for Al.
2,8,3
Write the electron configuration for Ar.
2,8,8
What is the pattern for how many electrons the shells can hold?
2,8,8,18,18,32,32
Write the electron configuration for Ca.
2,8,8,2
What is the molar mass of LiF? Find the number of moles of LiF with a sample mass of 50g. What is the molarity of a 250mL solution with 50g of LiF?
25.9 g/mole ; 1.9 moles ; 7.6M
Write a balanced chemical equation for calcium reacting with oxygen to form calcium oxide.
2Ca + O₂ → 2CaO
When H and O react, water is formed. Write the balanced chemical equation.
2H₂ + O₂ → 2H₂O
Balance - Na + Cl₂ → NaCl
2Na + Cl₂ → 2NaCl
Balance - Na₃PO₄ + CaCl₂ → NaCl + Ca₃(PO₄)₂
2Na₃PO₄ + 3CaCl₂ → 6NaCl + 1Ca₃(PO₄)₂
Sulfur and oxygen react to form sulfur-trioxide. Write the balanced chemical equation.
2S + 3O₂ → 2SO₃
How many moles of salt are needed to make 6 liters of a 0.5M solution?
3 moles
How many moles of NaBr would be needed to produce a 1.5M solution with 2.5L of solution?
3.75 moles
How many valence electrons does C have?
4
What is the molar mass of MgO? How many moles of MgO would be needed to make a 3M solution with 1.5L of volume? What is the sample mass used here of MgO?
40.3 g/mole ; 4.5 moles ; 181.4g
A double bond involves __ electrons and a triple bond involves __ pairs of electrons.
4;3
Determine the average atomic mass for these isotopes. 15% FE-55 and 85% FE-56.
55.85 amu
What is the molarity when water is added to 3 moles of potassium iodide to make 600mL of solution?
5M
How many shells does Au have?
6
How many valence electrons does O have?
6
How many molecules of CO₂ are in 44 grams?
6.02*10²³ molecules(1 mole)
1 mole of something is ____ atoms of it.
6.02*10²³(Avogadro's number)
How many valence electrons does Br have?
7
How many valence electrons does Ne have?
8
When atoms create covalent bonds, what is the max number of valence electrons they can have?
8
Oxygen's atomic # is __, it has __ valence electrons and it wants to bond to have __ more electrons to get the octet.
8,6,2
Acid → OH⁻ (<,>,=) H₃O⁺
<
The pH of an acid is (<, >, =) to 7.
<
Neutral solution → OH⁻ (<,>,=) H₃O⁺
=
The pH of a neutral solution is (<, >, =) to 7.
=
Base → OH⁻ (<,>,=) H₃O⁺
>
The pH of a base is (<, >, =) to 7.
>
Write the formula for the compound - silver bromide
AgBr
Write the Bronsted-Lowry definition of acid-base behavior.
BAAD(bases accept, acids donate)
List all the metalloids.
Boron, Silicon, Germanium, Arsenic, Antimony, and Tellurium
Which halogen is the only liquid non-metal?
Bromine
Write the chemical formula - hexaboron monosilicide
B₆Si
Methane burned in oxygen to produce carbon dioxide and water. Write the balanced chemical equation.
CH₄ + 2O₂ → CO₂ + 2H₂O
When CH₄ burns in oxygen gas, carbon dioxide and water are formed. Write a balanced chemical equation for this.
CH₄ + 2O₂ → CO₂ + 2H₂O
What molecule has a similar structure to the bonding diagram to Silicon dioxide?
CO₂
Write the chemical formula - chlorine dioxide
ClO₂
Write the formula for the compound - cobalt(III) oxide
Co₂O₃
Write the formula for the compound - chromium(III) hydroxide
Cr(OH)₃
Write the formula for the compound - chromium(VI) phosphate
Cr(PO₄)₂
What is the formula for a combustion reaction?
CxHy + O₂ → CO₂ + H₂O
Which element has the highest/lowest electronegativity?
Fluorine/Francium
List the diatomic elements.
H, N, O, F, Cl, Br, I
Which elements are diatomic?
H, N, O, F,Cl, Br, I
List the 3 strong acids.
HCl, H₂(SO₄), HNO₃
Write the chemical formula - hydrogen monoiodide
HI
If there is He and Rn in a room, where would you find them and why?
He near ceiling because it's light; Rn near floor because it's heavy
A proton can be written how?
H⁺
Acids donate __ ions in water to form __.
H⁺, H₃O⁺
Write the chemical formula - dihydrogen monoxide
H₂O
A strong acid ionizes completely and produces a large concentration of ___, making it a good conductor.
H₃O⁺
An acidic solution has a high concentration of __.
H₃O⁺
Write the formula for hydronium.
H₃O⁺
A neutral solution has an equal number of __ and __.
H₃O⁺, OH⁻
A strong acid has a high concentration of __. A strong base has a high concentration of __.
H₃O⁺, OH⁻
A weak acid has a lower concentration of ___. A weak base has a lower concentration of __.
H₃O⁺, OH⁻
H₂O + H⁺ → (give chemical formula & name)
H₃O⁺; hydronium
Write the chemical formula - iodine pentaflouride
IF₅
K(OH) + HCl → ?
KCl + H₂O
List the following from high pH to low pH. KOH, HCl, NH₄(OH), distilled water, vinegar
KOH, NH₄(OH), distilled water, vinegar, HCl
Li(OH) + HBr → ?
LiBr + H₂O
Write the formula for the compound - lithium iodide
LiI
If a proton is added to HE nucleus, what nucleus do you get?
Lithium
Write the formula to find molarity(moles per liter).
M = # of moles of solute/ # of liters of solution
Mg(OH)₂ + 2HCl → ?
MgCl₂ + 2H₂O
Write the chemical formula - nitrogen tribromide
NBr₃
Name a base without hydroxide in the formula.
NH₃
Write the chemical formula - nitrogen trihydride(ammonia)
NH₃
List the 3 strong bases.
NaOH, KOH, Ca(OH)₂
Write the chemical formula - dinitrogen trioxide
N₂O₃
A basic solution has a high concentration of __.
OH⁻
Write the formula for hydroxide.
OH⁻
H₂O - H⁺ → (give chemical formula & name)
OH⁻; hydroxide
Write the chemical formula - phosphorus triiodide
PI₃
Write the formula for the compound - lead(II) nitride
Pb₃N₂
Marie Curie discovered which elements?
Polonium and Curium
Write the chemical formula - diphosphorus pentaoxide
P₂O₅
Write the formula for the compound - tin(II) nitrite
Sn(NO₂)₂
Write the formula for the compound - titanium(II) acetate
Ti(C₂H₃O₂)₂
Write the formula for the compound - vanadium(IV) carbonate
V(CO₃)₂
Write the formula for the compound - vanadium(V) sulfide
V₂S₅
What is the formula for a synthesis reaction?
a + b → ab
What is a mixture?
a material in which 2 or more substances are present but have not bonded
What is a catalyst?
a substance that lowers the Ea without being consumed by the reaction
What is the formula for a single replacement reaction?
ab + c → ac + b
What is the formula for a double replacement reaction?
ab + cd → ac + bd
What is the formula for a decomposition reaction?
ab → a + b
Identify the acid or base behaviors for this equation. HNO₃ + H₂O → H₃O⁺ + NO₃⁻
acid, base, acid, base
list acid/base behaviors - HCO₃⁻ + H₂O → H₃O⁺ + CO₃²⁻
acid, base, acid, base
Given this pH value, is the solution acidic, basic, or neutral? 6
acidic
How do you find molar mass?
add the atomic weights(g/mole)
Name all the families except transition metals.
alkali metals, alkaline earth metals, boron family, carbon family, nitrogen family, chalcogens, halogens, noble gases
Name the ionic compound - NH₄CL (NH₄ = ammonium)
ammonium chloride
If a neutron is added to HE nucleus, what do you get?
an isotope of HE with 1 extra mass
Why are ashes sometimes used to clean greasy dishes/hands?
ashes are bases, which emulsify fats/oils
The modern per. table is in order of ___.
atomic #
Mendeleev's per. table was in order of __.
atomic mass
What can be learned from Democritus' Greek model of the atom?
atoms are the smallest particles and they are indivisible
What did Niels Bohr discover?
atoms emit a unique emission spectra when energized
There are 2 elements, A(circles) and B(squares). In box 1, there are only circles so this box contains __.
atoms of element A
What 3 things can be learned from Dalton's model of the atom?
atoms of the same/different elements are the same/different; law of definite composition - fixed ratio for compounds
What is the octet rule?
atoms want 8 valence electrons
Define atomic mass.
average weight of all isotopes
What are some properties of non-metals?
bad conductors, transparent, brittle, not ductile or malleable
If the number of times an element appears as a reactant is equal to the number of times it appears as a product, the equation is ___.
balanced
When a salt is formed from a neutralization reaction, the positive ion of the salt comes from the ___ and the negative comes from the ___.
base, acid
Identify the acid or base behaviors for this equation. NH₃ + H₂O → NH₄⁺ + OH⁻
base, acid, acid, base
Given this pH value, is the solution acidic, basic, or neutral? 13
basic
What happens to atom size going down the family?
bigger; more shells
List some properties of bases.
bitter, slippery, accept H⁺ ions, pink in phenolphthalein, blue in litmus
The amount of energy absorbed as a chemical bond is broken or released as the bond forms is called __.
bond energy
Why would Ca and Sr have similar properties?
both in family 2; 2 valence electrons
What happens in a chemical reaction?
break old bonds, form new bonds
How does one treat the problem of acid indigestion?
by eating antacids(bases)
Name this compound - CaO
calcium oxide
Write the name for the covalent compound - CH₄
carbon tetrahydride (methane)
What was the name of the experiments that J.J. Thompson did?
cathode ray tube experiments
Physical or Chemical? - a person gains 20 pounds
chemical
Physical or Chemical? - burning of paper
chemical
Physical or Chemical? - tree growing
chemical
You were 5' in 6th grade. Now, you are 5'4". Is this a physical or chemical change?
chemical
The force of attraction between 2 atoms that hold them together is called what?
chemical bond
Box A has red atoms and blue atoms bonded together. Box A becomes box B, which has red bonded with red and blue bonded with blue. A to B is what kind of change?
chemical change
There are 3 groups of atoms, one cold, one warm, one very hot. Which would have the highest density and how would the atoms be packed?
cold; tightly packed
What cannot change during a physical change?
composition/identity
A material in which different elements are bonded together is called a ___.
compound
There are 2 elements, A(circles) and B(squares). In box 2, each circle is bonded with a square. This box has a ___.
compounds
Name the ionic compound - Cu₂P
copper phosphide
Electrons are shared in ____ bonds.
covalent
What type of bond do non-metals share?
covalent
Name the type of reaction. H₂CO₃ → H₂O + CO₂
decomposition
By lowering the temperature, the reaction rate ₋₋₋
decreases
When you dilute NaOH or any base, what happens to the pH?
decreases
Write the name for the covalent compound - B₂Si
diboron monosilicide
Determine if these are isotopes or different elements. Element x has 50 protons and 36 neutrons. Element y has 51 protons and 110 neutrons.
different
The properties of a compound are ___ from the properties of its parent elements.
different
Explain what gives polar covalent molecules polarity.
different electronegativities
Write the name for the covalent compound - H₂O
dihydrogen monoxide (water)
Give the chemical name for this compound - N₂O
dinitrogen monoxide
Write the name for the covalent compound - N₂O₅
dinitrogen pentaoxide
Write the name for the covalent compound - Si₂Br₆
disilicon hexabromide
Name this compound - S₂F₁₀
disulfur decaflouride
Acids ___ H⁺ ions and bases __ them.
donate, accept
O₂ is an example of a compound with a ___ bond, and N₂ has a ___ bond.
double / triple
Name the type of reaction. HCl + NaOH → NaCl + H₂O
double replacement
The attraction to electrons that elements have is called ____.
electronegativity
What did J.J. Thompson discover?
electrons
Define valence electrons.
electrons on outer shell that determine chemical properties
Compounds are created by bonding atoms of different ______ together.
elements
A reaction in which net energy is absorbed is called an _____ reaction.
endothermic
When a battery is being recharged, what type of reaction is going on?
endothermic
When melting a solid substance into liquid form, energy is added. Is this exothermic or endothermic?
endothermic
___ in our bodies speed up chemical reactions by acting as catalysts.
enzymes
A reaction in which net energy is released is called an _____ reaction.
exothermic
When a battery is being used, what type of reaction is occurring?
exothermic
When a substance goes from its gaseous state to liquid state, energy is given out. What type of reaction is this?
exothermic
While doing an experiment, the sides of the test tubes feel warm? What type of reaction is it?
exothermic
Exothermic or endothermic? 2H₂ + O₂ → 2H₂O {H-H = 436 kj, O⇌O = 498 kj, H-O = 464 kj}
exothermic(1370 vs 1856, 486kj net energy released)
Exothermic or endothermic? H₂ + Cl₂ → 2HCl {H-H = 436kj, Cl-Cl = 243kj, H-CL = 431kj}
exothermic(679 vs 862)
Given different bonding combinations between atoms, how would you determine which is the least/most polar?
further apart on periodic table = more polar
In an ionic bond, the nonmetal gains/loses electron(s) making it a +/- charged ion.
gains ; -
What was the name of the experiments conducted by Rutherford?
gold foil experiments
Define element.
has 1 type of atom
For a slow chemical reaction, the activation energy is __. For a fast one, the Ea is ___.
high; low
Higher temperature means ___ reaction rate because there are ___ collisions.
higher; more
What were Bohr's experiments called?
his were based on math
What purpose do subscripts have in a chemical equation? Coefficients?
how many of that atom; how many of the molecule
H₃O⁺ ions are called __, and OH⁻ ions are called __.
hydronium ions, hydroxide ions
More surface area __ the reaction rate.
increases
When you dilute HCl or any acid, what happens to the pH?
increases
By crushing sugar cubes into a powder, what happens to the surface area and the reaction rate with other chemicals?
increases; higher
Electrons are transferred in ___ bonds.
ionic
What type of bond occurs between a metal and non-metal?
ionic
Name the ionic compound - Fe(NO₃)₃ [NO₃=nitrate]
iron nitrate
Determine if these are isotopes or different elements. Element x has 2 protons and 2 neutrons. Element a has 2 protons and 1 neutron.
isotopes
Matter is neither created nor destroyed in a chemical reaction. The same atoms are used. What law is this?
law of conservation of mass
Where are metals, non-metals, and metalloids located on the per. table?
left, right, between metals and non-metals
The reactants have ___ PE than the products in an endothermic reaction.
less
Name this compound - Li₂S
lithium sulfide
Name 3 indicators that can be used to test if something is an acid or a base.
litmus paper, phenolphthalein, bromthymol blue
How do you identify a catalyst?
look at all the steps of the reaction and the substance always being regenerated is the catalyst
How does an atom become a +/- ion?
lose/gain electrons
In an ionic bond, the metal gains/loses electron(s) making it a +/- charged ion.
loses ; +
Name this compound - MgBr₂
magnesium bromide
What does a pH probe do?
measures pH
What type of bond exists in a metal? What properties does it give?
metallic bonds; loose electrons allow conductivity
A group of atoms is called a ___.
molecule
Are atoms made of molecules or molecules made of atoms?
molecules are made of atoms
There are 2 elements, A(circles) and B(squares). In box 3, each circle is bonded with a circle. This box has __.
molecules of element A
List the prefixes used for naming compounds. 1-6
mono, di, tri, tetra, penta, hexa
The reactants have ___ PE than the products in an exothermic reaction.
more
What is a polyatomic ion?
multiple atoms that act as 1 ion
Given this pH value, is the solution acidic, basic, or neutral? 7
neutral
Write the name for the covalent compound - NF₃
nitrogen triflouride
When salt and water are produced from a neutralization reaction, are they corrosive like the acid and base?
no
Does the ratio of elements in a compound change?
no; always constant
Is Hydrogen a metal or non-metal?
non-metal
When 2 of the same atom create a covalent bond, they are called ____ molecules.
non-polar
Why is water not classified as a salt even when it is produced from a neutralization reaction?
not an ionic compound
Polar(p) or non-polar(np)? - CH₄
np
Polar(p) or non-polar(np)? - CO₂
np
Polar(p) or non-polar(np)? - I₂
np
Polar(p) or non-polar(np)? - N₂
np
Polar(p) or non-polar(np)? - O₂
np
Polar(p) or non-polar(np)? - SO₂
np
Write the name for the covalent compound - O₂
oxygen
Polar(p) or non-polar(np)? - CHCl₃
p
Polar(p) or non-polar(np)? - CH₃OH
p
Polar(p) or non-polar(np)? - HF
p
Polar(p) or non-polar(np)? - H₂O
p
Polar(p) or non-polar(np)? - H₂S
p
Polar(p) or non-polar(np)? - NH₃
p
The measure of the acidity of a solution is __.
pH
# of shells = ___.
period # on per. table
Name this compound - PBr₃
phosphorus tribromide
Physical or Chemical? - aluminum is malleable
physical
Physical or Chemical? - copper conducts electricity
physical
Physical or Chemical? - ice melting
physical
Physical or Chemical? - sugar cubes are crushed to a powder
physical
You are 5' in the morning. Before going to bed, you are 4'11 1/2". When you wake up, you are 5' again. At night, you are 4'11 1/2" again. Is this physical or chemical?
physical
What was Bohr's model called?
planetary model
What was J.J. Thompson's model called?
plum pudding model
By looking at the bonding diagrams, how would you determine if it is polar or non polar?
polar = non-symmetrical; non-polar = symmetrical
When writing exothermic reactions, the word energy is written on the (reactant/product) side of the reaction.
product
What a chemical reaction produces are called __.
products
Which sub-atomic particle deciphers one atom from another?
proton
How do you differentiate a strong/weak acid/base in a lab?
put the wires of a circuit in the substance and if the bulb is bright the solution is strong
List some properties of acids.
react with metals to form H₂, sour, donate H⁺ ions, colorless in phenolphthalein, red in litmus
When writing endothermic reactions, the word energy is written on the (reactant/product) side of the reaction.
reactant
The reacting substances in a chemical reaction are called ____.
reactants
__ is a measure of how quickly the concentration of products in a chemical reaction increases or the concentration of reactants decreases
reaction rate
An ionic compound formed from the reaction of an acid and base is called a ___.
salt
Define isotope.
same # of p; different n
Write the formula for # of moles.
sample mass / molar mass
Give the chemical name for this compound -ScF₄
scandium flouride
What are some properties of metals?
shiny, good conductors of heat and electricity, malleable and ductile
Name the type of reaction. Zn + 2HCl → ZnCl₂ + H₂
single replacement
What happens to atom size going across periods?
smaller; more protons pulling in on shells
Define atom.
smallest particle of matter, has all the properties of its element
Name this compound - NaI
sodium iodide
Is the attraction force highest in a solid, liquid, or gas?
solid
Give the chemical name for this compound - SO₂
sulfur dioxide
Write the name for the covalent compound - SF₆
sulfur hexaflouride
Write the name for the covalent compound - SCl₄
sulfur tetrachloride
Name the type of reaction. 2H₂ + O₂ → 2H₂O
synthesis
What does pH paper do?
tells you the pH of a substance via color patterns
What are the 4 factors that affect the reaction rate?
temperature, concentration, surface area, catalyst
Write the name for the covalent compound - P₄S₅
tetraphosphorus pentasulfide
When adding Alka-Seltzers to water, there is vigorous bubbling. But when adding them to water with alcohol, there is less bubbling. Explain
the alcohol lowers the concentration of water and slows the reaction rate
Why do polar molecules have a high boiling point/vice versa with non-polar?
the atoms in polar molecules are attracted to each other which makes them harder to separate
What is activation energy?
the energy needed to start the chemical reaction
Which reactants are the first to become products in a chemical reaction?
the first ones to cross the energy barrier
In Fe(II), what does the Roman Numeral indicate?
the oxidation # ; 2+ in this case
Why can we not breathe oxygen from H₂O?
the oxygen is tightly bonded with the H
A can of soda is opened and the soda goes flat. What happens to the pH of the soda and why?
the pH increases because soda is acidic and the CO₂ escaping dilutes the acid
The Bohr model of the atom looks like ___.
the solar system
Define electronegativity.
the tendency for an atom to bond
What is special about noble gases?
their shells are 100% filled; non-reactive
Burning a log in pure O₂ vs air speeds up the burning because __.
there is a higher concentration of oxygen
Why do noble gases not react?
they don't need to bond
Why are valence electrons important?
they take part in chemical reactions
How are particles arranged in a solid/liquid/gas?
tightly packed; loosely packed and moving some but still definite volume; free movement, no definite shape
Name the ionic compound - SnSe₁₀₀
tin selenide
Name the ionic compound - TiBr₉
titanium bromide
Why is energy needed to break apart the bonds in a chemical reaction?
to overcome the electrical attraction forces
Why is food refrigerated?
to slow down the chemical reaction of food spoiling
There are 3 groups of atoms, one cold, one warm, one very hot. Which would have the lowest density and how would the atoms be packed?
very hot; freely moving
What are the products of an acid base neutralization reaction?
water and a salt
When an acid and a base react, they form ____. What is this reaction called and what type of a reaction is it?
water and a salt; neutralization reaction; double replacement
Can a piece of chalk(base) treat acid indigestion?
yes