Chemistry mass practice questions Flashcards
What is considered the universal solvent?
water
What are the letter shells corresponding to 1,2,3,4 energy levels? How many electrons can they hold?
- K-2
- L-8
- M-18
- N-32
What type of cmpd has an oxygen mlc linking 2 hydrocarbons
ether
Aldehydes and ketones contain what type of functional group?
carbonyl (C=O)
Alcohol contains what type of functional group?
hydroxyl (-OH)
What compound has a nitrogen atom with a lone pair of electrons that is bound to one or more hydrocarbons
amines
What are 3 other extensive properties I didn’t learn from notes?
- entropy
- number of moles
- electrical charge
What is 1 other intensive property i didn’t learn about in my notes?
temperature
An object that changes color in the prescence of hydrogen or hydronium ions is said to be what?
halochromic
What type of materials change in color in the presence of pressure?
piezochromic
bioluminescence is a form of what?
chemiluminescence
What type of compounds are salts? What are the examples i learned about for ____ rxns?
- ionic cmpds
- neutralization rxns
Examples
* NaHSO4 - sodium bisulfate
* K2Cr2O7- potassium dichromate
* CaCl2- calcium chloride
* NaNO3/ KNO3 - in fertilizer
* MgSO4- epsom salt
What type of structure does a solid form?
lattice structure
Which of the following best describe oxygen with 8 protons, 10 electrons and 8 neutrons?
* oxygen isotope with a atomic mass of 2
* oxygen as an isotope with an atomic mass of 16
* oxygen as an anion with a -2 charge
* oxygen as a cation with a -2 charge
C
* charge = protons + electrons
* mass= protons + neutrons
isotope has DIFF NUMBER OF NEUTRONS, and so mass number
As you go from pH 7 to pH 1, what is happening to the strength of the ___?
- acid
- increasing
As you go from pH 7 to pH 14, what is happening to the strength of the ___?
- base
- increasing
What number on the pH scale is HCl?
1
What are additional examples of homogenous mixtures besides salt water and sln?
milk, air, blood, black coffee
What are additional examples of heterogenous mixtures besides oil and water?
pizza and tea with boba
He has a higher IE than fluorine. T or F
true based on periodic table trend of IE
What is the MOST EN atom?
FLOURINE
A synthesis / combination reaction ALWAYS has how many products?
ONE
Metals tend to ___ electrons because _____
- lose
- they have fewer electrons in their outer/ valence shell to begin with
Non-metals tend to ___ electrons because _____
- gain
- they have more electrons in their outer/ valence shell to begin with so easier to gain than lose electrons to get full valence shell of 8 to meet octet rule to be like the nearest noble gas
What type of bond is CCl4 with C EN being 3.0 and Cl being 2.5
3.0-2.5 = 0.5 so is a POLAR COVALENT BOND.
What is the average number of neutrons in a Bromine atom?
44.9
* neutrons = mass # (tho NOT rounding the atomic mass) - # of protons
* 79.9- 35 = 49.9
What is the number of neutrons in a Bromine atom?
- neutrons = mass # - # of protons
- 80-35=40
What is the SI unit of mass?
kg
Matter exists in how many states?
4
* S, L, G, and plasma (least common)
What are new definitions of mass and volume i learned?
- mass: the number of mlcs in an obj
- volume: the amount of space the mlcs in an obj occupt
matter is made up of atoms and also what?
mlcs
matter can exist in ___ states depending on the ____
- different
- environment
What is the correct conjugate acid for NH3?
NH4+ (ammonium)- a weak acid
What are two elemenets that DO NOT follow the octet rule? Instead what rule do they follow? What does that rule say?
- H and He
- DUET rule
- only need 2 electrons in valence/ outer shell.
What are some pieces of evidence that a chemical reaction has taken place?
- color change
- release of light
- formation of a solid precipitate
- formation of gas (ie. bubbles)
- change in temperature
- change in chemical composition/ chemical identity
Dipole always points towards the ___ EN atom
MORE
Balance the following chemical equation
C2H6 + O2 –> CO2 + H2O
2,7,4,6
when original Coeff dont work x2 the ones i have
What elements should be balanced last?
O and H
Balance the following chemical equation
Ca3N2 + H2O –> Ca (OH)2 + NH3
1,6,3,2
lesson: parenthesis = distribute to atoms
What is the correct number of protons, neutrons, and electrons for the given isotope?
16
O -2
8
- protons = atomic number = 8
- neutrons = mass number - number of protons = 16-8= 8
- electrons [ protons + electrons = charge], so 8+ _ = -2 ; -10
How many protons, neutrons, and electrons does Al ion with a 3+ charge have?
- protons = atomic number = 13
- neutrons = mass # - # of protons = 27-13= 14
- electrons [ protons + electrons = charge], so 13 + _ = +3; -10, so 10 electrons
If more energy is required to remove a valence electron from an atom, then the IE ____
increases
- Items that are ___ dense than water will float in water
- What is the normal density of pure water?
- less
- 1 g/ cm^3
What has no definite shape or volume and is an excellent conductor of electricity?
plasma (similar to gas) (plasma is also affected by magnetic fields)
