Chem 1307 Midterm 1—Final Study Guide
107 g
Magnesium fluoride is used in the ceramics and glass industry. what is the mass of 1.72 mol of magnesium fluoride?
0.186 mol
Phosphorus pentachloride, PCl₅, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7g of PCl₅
3+
Predict the charge of the most stable ion aluminum
4.2 g
Reported with the proper number of sig figs, what is the result of subtracting the measured values: 14.6g - 10.435g
4.95 x 10⁻² mL
The density of ethanol is 0.789 g/cm³. What volume is 25.6 g of ethanol expected to occupy?
0.491 lb/in³
The density of mercury, the only metal to exist as a liquid at room temp, is 13.6 g/cm³. What is the density expressed in pounds per cubic inch? (1 in=2.54 cm, 1 lb=454 g)
10⁵ ergs
The joule is the SI unit of energy and is equal to 1 kg m²s⁻². The erg is another energy unit, equal to 1 g cm²s⁻². Use unit conversion methods to work out how many ergs are 1 joule.
barium phosphate
The name of the compound Ba₃(PO₄)₂
0.06
The result of (3.8621 x 1.5630)-5.98 reported to the correct number of sig figs is
6.520 x 10⁴ ft/min
The speed of sound in air is 331.2 m/s. What is the speed of sound expressed in units of ft/min? (2.54 cm=1 in, 1 ft=12 in)
1 x 10⁻¹²
What decimal power does the abbreviation pico represent?
Cr₃C₂
What is the formula for chromium (III) carbonate?
P₂O₅
What is the formula that describes diphosphorus pentaoxide
28.1%
What is the percent by mass of sulfur in Al₂(SO₄)₃ (342.16 g/mol)?
5.20302 x 10⁴ m
Which of the following correctly expresses 52,030.2 m in scientific notation?
ammonium fluoride
Which of the following in as ionic compound
Rn
Which of the following is a noble gas?
H₂SO₃
Which of the following is the formula of sulfurous acid?
50.0 g of Li₂O
Which of the following samples has the most moles of the compound?
Rust (Fe₂O₃) forms readily when iron is exposed to moist air.
Which one of the following is a chemical property of iron?
ClO₄⁻
Which species below is the perchlorate ion?
2.05 x 10²⁴
How many atoms are in 3.40 moles of nickel?
4.22 x 10³ g
How many grams of Co are found in 4.31 x 10²⁵ atoms of Co?
7.41 x 10²² molecules
How many molecules of methane are there in 0.123 moles of methane (CH₄)?
9.0 x 10²³ atoms
How many oxygen atoms are present in 32.4 g of N₂O₅
7
How many sig figs does the number 0.004903080 have?
88.2 amu
A hypothetical element consists of two isotopes of masses 86.95 amu and 88.95 amu with abundances of 35.5% and 64.5%, respectively. What is the average atomic mass of this element?
79, 118, 79
An atom of the most abundant isotope of gold ¹⁹⁷Au has ___protons, ___neutrons, and ___electrons.
³¹p³⁻
An ion has 15 protons, 16 neutrons, and 18 electrons. The symbol for the ion is
78.07 g/mol
Calcium fluoride, CaF₂, is a source of fluorine and is used to fluorinate drinking water. Calculate its molar mass.
4.976 x 10²³ O atoms
Calculate the number of oxygen atoms in 29.34g of Sodium Sulfate, Na₂SO₄
9.6 x 10⁴m
Express 96,342 m using 2 sig figs