Perform the following calculation (present your final answer with the correct number of significant figures): (8.32 x 107) / [(4/3)(3.1416)(1.95 x 102 cm)3] = ____ g/cm3
2.68 g/cm3
Below, ionic formulas are paired with names of ions. Which names are incorrectly matched with the formula?
HPO42- --> hydrogen phosphate
ClO4- --> perchlorate
MnO4- --> permanganate
O2- --> oxide
N3- --> nitride
ClO3- --> chlorite
NO2- --> nitrite
MnO4- --> permenganate
Cd2+ --> cadmium ion
O2- --> oxide & ClO3- --> chlorite
Which of the following samples has the least moles of the compound?
100g of KHSO3
50g of Na2O
75g of BeO
50g of CO2
200g of Co3O4
50g of Na2O
Balance the equation given below:
___BaCO3(aq) + ___HNO3(aq) --> ___Ba(NO3)2(s) + ___ CO2(aq) + ___H2O(l)
1 BaCO3(aq) + 2 HNO3(aq) --> 1 Ba(NO3)2(s) + 1 CO2(aq) + 1 H2O(l)
Rubidium has two principle isotopes, 85Rb (84.911789 amu) and 87Rb (86.909183 amu). What is the percentage abundance of the lower mass isotope?
72.05 %
The current value of pure gold on the commercial market is $35,548.44 per kg. At that price, what would be the value of the gold in 0.4680 mol of gold (III) chloride?
$3277
What is the name of alkali metal that is in period 5?
What is the name of the halogen that is in period 4?
What is the name of the alkaline earth metal that is in period 4?
What is the name of the noble gas that is in period 1?
rubidium
bromine
calcium
helium
How many grams of NaH2PO4 are needed to completely neutralize 43.78 mL of a 0.275 M NaOH solution?
Balance the chemical equation first:
___NaH2PO4(s) + ___NaOH(aq) --> ___Na3PO4(aq) + ___H2O(l)
1 NaH2PO4(s) + 2 NaOH(aq) --> 1 Na3PO4(aq) + 1 H2O(l)
0.722 g of NaH2PO4(s)
Write the balanced chemical equation for the combination reaction described, using the smallest possible integer coefficients.
When hydrogen combines with iodine, hydrogen iodide is formed.
H2(g) + I2(g) --> 2HI(g)
The oxidation state of sulfur in sulfur solid (S8) is ___.
The oxidation state of bromine in bromine gas (Br2) is ___.
The oxidation state of fluorine in fluorine gas (F2) is ___.
0
0
0
Match the physical property on the left with the name of its SI units of measurement on the right.
temperature meter
time kilogram
amount of a substance second
mass ampere
electric current kelvin
luminous intensity candela
length mole
temperature kelvin
time second
amount of a substance mole
mass kilogram
electric current ampere
luminous intensity candela
length meter
What is the name of the compound with the formula Ca(CH3COO)2?
What is the name of the compound with the formula SF4?
What is the formula for chromium(III) sulfate?
What is the formula for nitrogen trifluoride?
calcium acetate
sulfur tetrafluoride
Cr2(SO4)3
NF3You need to make an aqueous solution of 0.181 M silver nitrate for an experiment in lab, using a 250 mL volumetric flask. How much solid silver nitrate should you add?
7.69 grams
Classify each of the compounds as soluble or not soluble and write its chemical formula:
cobalt(II) nitrate
nickel(II) bromide
iron(II) sulfide
cobalt(II) nitrate : soluble : Co(NO3)2
nickel(II) bromide : soluble : NiBr2
iron(II) sulfide : not soluble : FeS
Identify the species oxidized, the species reduced, the oxidizing agent, and the reducing agent in the following electron transfer reaction.
Cu2+ + 2Cr2+ --> Cu + 2Cr3+
As the reaction proceeds, electrons are transferred from ___ to ___.
Species oxidized: Cr2+
Species reduced: Cu2+
Oxidizing agent: Cu2+
Reducing agent: Cr2+
As the reaction proceeds, electrons are transferred from Cr2+ to Cu2+.
Classify each of the following changes as chemical or physical.
Combustion of gasoline :
Sweetening coffee with sugar :
Ripening of bananas :
Combustion of gasoline : chemical
Sweetening coffee with sugar : physical
Ripening of bananas : chemical
What is the element symbol, atomic number, mass, number, # of protons, # of neutrons, and # of electrons for each of the elements whose nuclear symbols are given?
12151Sb
84Be
12351Sb
Sb, 51, 121, 51, 70, 51
Be, 4, 8, 4, 4, 4
Sb, 51, 123, 51, 72, 51
An aqueous solution of nitric acid is standardized by titration with a 0.138 M solution of barium hydroxide. If 28.5 mL of base are required to neutralize 29.9 mL of the acid, what is the molarity of the nitric acid solution?
0.263 M HNO3
When aqueous solutions of ammonium phosphate and zinc nitrate are combined, solid zinc phosphate and a solution of ammonium nitrate are formed. The net ionic equations for this reaction is:
2 PO43-(aq) + 3 Zn2+(aq) --> Zn3(PO4)2(s)
A sample of an industrial waste water is analyzed and found to contain 26.8 ppb Zn2+. How many grams of zinc could be recovered from 1.86 x 103 kg of this waste water?
0.0498 grams Zn
Solid: particles in a solid are held in place by attractive forces, and are often found in closely packed, well-ordered arrays. The particles vibrate, but remain in fixed positions relative to each other. A solid has a fixed volume and definite shape.
Liquid: particles in a liquid are only loosely held together by attractive forces, so that they are able to move relative to each other. A liquid has a definite volume, but assumes the shape of the bottom of its container.
Gas: in a gas, attractive forces are not strong enough to hold the particles together, so they are not in contact and move randomly throughout the container. A gas fills its container completely and assumes its shape and volume.
When the following molecular equation is balanced using the smallest possible integer coefficients, the values of these coefficient are:
___butane(C4H10)(g) + ___ oxygen(g) --> ___carbon dioxide(g) + ___water(g)
2 C4H10(g) + 13 O2(g) --> 8 CO2(g) + 10 H2O(g)
When 1.715 grams of a hydrocarbon, CxHy, were burned in a combustion analysis apparatus, 5.255 grams of CO2 and 2.510 grams of H2O were produced. In a separate experiment, the molar mass of the compound was found to be 86.18 g/mol. Determine the empirical formula and the molecular formula for the hydrocarbon.
Molecular Formula: C6H14
For the following reaction, 9.70 grams of sulfur are allowed to react with 19.9 grams of carbon monoxide.
sulfur (s) + carbon monoxide (g) --> sulfur dioxide (g) + carbon (s)
What is the maximum amount of sulfur dioxide that can be formed?
What is the FORMULA for the limiting reagent?
What amount of excess reagent remains after the reaction is complete?
19.4 grams is the max. amount of sulfur dioxide that can be formed.
the formula for the limiting reagent is S.
the amount of excess reagent that remains after the reaction is complete is 2.95 grams.
For the following reaction, 3.80 grams of sulfuric acid are mixed with excess barium hydroxide. The reaction yields 7.79 grams of barium sulfate.
barium hydroxide (aq) + sulfuric acid (aq) --> barium suldate (s) + water (l)
What is the theoretical yield of barium sulfate?
What is the percent yield of barium sulfate?
Theoretical yield: 9.042 grams BaSO4
Percent yield: 86.2 %