Chapter 1
What is the difference between a physical change and a chemical change? Provide an example of each.
A physical change only alters the appearance or phase of a substance rather than its composition or identity. (Example: water boiling or salt dissolving in water etc.) Meanwhile, a chemical change does alter the composition or identity of a substance. (Example: wood burning or fireworks etc.)
Which law states that elements may combine in more than one ratio, but they will no longer be the same compound?
Law of Multiple Proportions
Which of these is an example of an ionic bond? Why?
1) CO32- 2) (NH3)2SO4
3) Cs3PO4 4) Fe (II)
Cs3PO4 because it is a metal bonded with a polyatomic
How many molecules are in 5.13 mg of butane (C4H10)?
5.32 x 1019 molecules of butane
A flash drive has a capacity of 8.71 x 1019 nanobytes. How many gigabytes of storage can it hold?
87.1 gigabytes
What does (756.09 - 54.2004) / (90. x 6.41) equal?
1.2
What did Millikan's oil drop experiment discover? Also, what did Rutherford's experiment discover?
Millikan: The charge of an electron
Rutherford: The structure of the atom contains a positively charged nucleus and that a protons charge is opposite of the electron.
Provide the names/formulas for the following compounds:
1) Lithium Nitride 2) N2O3 3) ClO4- 4) Carbonate 5) HCl
1) Li3N 2) Dinitrogen Trioxide 3) Perchlorate
4) CO32- 5) Hydrochloric Acid
Find the masses of N and H in 12.7 g of N3H5
N = 11.3 g
H = 1.36 g
How many kg are there in 7.09 x 1025 atoms of sodium perchlorate?
NaClO4
14.4 kg
The boiling point of liquid helium is -452.2 oF. What is its temperature in oC and K?
-269.0 oC and 4.2 K
An ion has 78 protons, 118 neutrons, and 76 electrons. What is the correct atomic symbol, atomic mass, atomic number, and charge for this element?
Platinum - Pt 196 78 2+
Balance the following equation:
_C3H12 + _O2 -> _C2O6 + _H2O
2, 15, 3, 12
Given the following balanced equation, how much water (in g) is needed to transfer 3.7 g of NO2 to nitric acid?
3NO2 (g) + H2O (l) -> 2HNO3 (aq) + NO (g)
0.48 g H2O
The density of a copper wire is 9.33 g/cm3. It has a diameter of 4.9 mm. If I have a 2.00 m length of wire, how many atoms of copper are there within it?
3.34 x 1024 atoms of copper
A liquid solvent is added to a flask containing an insoluble solid. The total volume of the solid and the liquid is 105 ml. The liquid solvent has a mass of 24.6 g and a density of 0.972 g/ml. What is the mass of the solid given its density is 2.83 g/ml?
226 g
The liberty bell is 943.5 kg, and is 70% Copper, 25% Tin, and trace amounts of Lead, Gold, Arsenic, Silver, and Zinc. How many molecules of Copper are there in the bell?
6.258 x 1027 molecules of copper
Find the empirical formula of a compound with a composition of 68.90% C, 4.92% H, and 26.18% O.
If the molar mass for this Compound Is 366.36 g/mol, what’s the molecular formula?
C7H6O2
C21H18O6
Given the following balanced equation, what is the limiting reagent if 9.88 g P2O5 is mixed with 7.50 g H2O?
P2O5 (s) + 3H2O (l) → 2H3PO4 (aq)
L.R. = P2O5
How many grams of water will be produced from 8.34 g of butane (C4H10) with excess oxygen?
_C4H10 + _O2 -> _CO2 + _H2O
2, 13, 8, 10
12.9 g
A carpet sells for $27.87 per square yard. How much does it sell for per square meter?
$33.33
Bromine has two stable isotopes, one with a mass of 79 and the other with a mass of 81. If the atomic weight for bromine on the periodic table is 79.904, what is the percent abundance of each isotope?
Isotope 79 = 54.8%
Isotope 81 = 45.2%
If a hydrate of Na2CO3 is heated to 250°C, all the water of hydration is lost. On heating a 1.687 g sample of the hydrate, 0.625 g of Na2CO3 remains. How many molecules of water occur per formula unit of Na2CO3?
Na2CO3.xH2O (s) + heat -> Na2CO3 (s) + __H2O (g)
10 molecules of water
Given the following balanced equation, what is the theoretical yield of HNO3 if 8.80 g NO2 reacts with 4.07 g H2O assuming NO2 is the limiting reagent.
3NO2 + H2O -> 2HNO3 + NO
Also, what is the percent yield when the actual yield is 2.37 g HNO3?
Theoretical yield = 8.04 g
Percent yield = 29.5%
A student mixed 8.05 g of iron (III) chloride with 7.64 g lithium hydroxide and got 4.13 g white precipitation of iron (III) hydroxide.
What is the maximum amount of iron (III) hydroxide that can be formed and what is the chemical formula for the limiting reagent?
FeCl3 + 3LiOH -> Fe(OH)3 + 3LiCl
1, 3, 1, 3
5.30 g
L.R. = FeCl3