official culmative exam study
_C6H1206(s) + _02 (g) — _CO2(g) +_ H2O (I)
1,6,6,6
a student has a sample of ispropanol. (C3H7OH) that has a mass of 78.6 g the molar mass of isopropanol is 60.1 g/ mol. how many miles of isopropanol are contained in this sample?
1.31 moles
which is the formula mass of (NH4)2SO4
132.17 amu
which is the molar mass of H20?
18.02 g/mol
consider the temperature versus time graph below. in which region is the substance in both the solid phase and the liquid phase?
2
if three molecules of hydrogen react with one molecule of nitrogen how many molecules of ammonia would be formed?
2
the balanced equation below shows the products that are forced when butane (C4H10) is combusted. what is the mole ratio of butane to carbon dioxide?
2:8
how many valence electrons does aluminum (Al) have available for bonding?
3
A balloon that had a volume of 3.50 L at 25.0°C is placed in a hot room at 40.0°C. If the pressure remains constant at 1.00 atm, what is the new volume of the balloon in the hot room?
3.68 L
the equation below shows lithium reacting with nitrogen to produce lithium nitride. if 12 mol of lithium were reacted with excess nitrogen gas, how many moles of lithium nitiride would be produced?
4.0 mol
ammonia is produced by the following reaction: 3H2(g) + N2(g) 2NH3(g) when 7.00 g of hydrogen react with 7.00 h of hydrogen react with 70.0 of nitrogen is considered the limiting reactant because
7.5 mol of hydrogen would be needed to consume the available nitrogen
what is the percent yield of oxygen in this chemical reaction?
73.40
the diagrams below represent the four states of matter. which diagram represents the phase that occurs after a solid melts?
Diagram 1 (A)
which best explains why ionization energy tends to decrease from the top to the bottom of a group?
Electrons get farther from the nucleus.
A single atom of an element has 11 protons, 11 electrons, and 12 neutrons. Which element is it?
Na
which element is the most reactive?
Sodium
some atoms are exceptions to the octet rule by having an expanded octet. which characteristic is needed for an atom to have an expanded octet?
The atom has empty d-orbitals.
a student performs the following experiment. step 1: she puts a colorless solution into a beaker that contains another colorless liquid. yellow particles appear in liquid. step 2: she lets the yellow particles settle in the beaker and then separates the colorless liquid by decantation what has most likely occurred in the beaker?
a chemical change in step 1 and a physical change in step 2
what is the relationship between a mole and avogardos number?
a mile contains avogardos number of particles of a substance
which physical method can be used for obtaining a sample of salt from a small beaker of salt water?
boiling
the diagram below shows the atoms involved in forming table salt. which statement best describes what happenes next?
chlorine becomes an anion by gaining an electron from sodium
which procedure could a student use to examine an intensive property of a rectangular block of wood?
determine density
the diagram shows the movement of particles from one end of the container to the opposite end of the container which event is most likely occurring?
effusion because there is a movement of a gas through a small opening into a larger volume
which sequence represents the relationship between temperature and volume as explained by the kinetic-molecular theory?
higher temperature -> more kinetic energy -> more space between particles -> higher volume
Image A: a roasting marshmallow Image B: melting ice Which statement about the two images is true?
image A shows a chemical reaction, and image B shows a physical change
what of daltons ideas about the atom did J.J thomson experiment disprove?
it disproved that atoms are indivisible
which of daltons ideas about the atom did J.J thomsons experiment disprove?
it disproved that atoms are indivisible
which statement correctly describes the phosphate ion, PO3-4
it is composed of one phosphorus atom and four oxygen atoms covalently bonded together, and there is a -3 charge distributed over the entire ion
the elements of which group are non reactive?
noble gases
which type of bond will form between two chlorine atoms?
nonpolar covalent bond
consider reaction below. 2K + Br2—>2K+2Br- what is being reduced?
only Br2
air is made up of different gases such as oxygen nitrogen and carbon dioxide. which statement best describes these three components of air?
oxygen, nitrogen, and carbon dioxide are all classified as pure substances
which state of matter is characterized by ionized particles, no definite shape or volume and good electrical conductivity?
plasma
a chemical reaction that has the general formula of AB+C—-> CB+A is best classified as _____ reaction
replacement
The gas in the piston is being heated, and the piston has moved upward. The observation will be summarized in a row of the incomplete table below. What are the variables for this piston?
temperature and volume
which of the following compounds would be expected to have the strongest ionic bonds
the compound that has the smallest ions with the greatest charge