Chem101 Questions
How many milliliters are in a liter?
1000 mL
A mole is defined as the number of carbon atoms in __________ g of pure ¹²C.
12
Determine the molar mass of CH₃OH.
32.04 g/mol
The accepted value for the density of iron is 7.9 g/mL. Which of the following sets of experimental data for the density of iron is the most accurate?
A) Group 1: 7.98 g/mL, 7.85 g/mL (Accuracy is when the average of the set of measurements is in the range of uncertainty of the accepted value. Group 1, 7.98 g/mL, 7.85 g/mL, is the most accurate.)
How would you determine the formula weight of NaCl?
Add the mass of sodium (22.99 amu) plus the mass of chlorine together (35.45 amu).
The accepted value for the density of iron is 7.9 g/mL. Which of the following sets of experimental data for the density of iron is the most precise?
Group 2: 7.65 g/mL, 7.64 g/mL Precision is when all measurements are within the range of uncertainty of one another. Group 2, 7.65 g/mL and 7.64 g/mL, is the most precise.
Which of the following is an example of an extensive property of copper nugget?
It has a mass of 52.3 g. ( An extensive property is one that depends on the amount of the substance present.)
Which of the following is a physical change?
Subtract 273.15 (The formula for converting Kelvin to Celsius is:°C = K - 273.15)
Which of the following is a physical change?
Water is boiled in a microwave. -The process of boiling water is a phase change from liquid to gas and represents a physical change.
A mole equals any element's ___________.
atomic weight
Which of the following is an intensive physical property of a lump of coal?
color (The color of the coal can be observed through physical means (the naked eye), and does not depend on the amount of coal present.)
Which of the following are physical properties of matter?
density
Which of the following are chemical properties of matter?
flammability
What is the correct IUPAC name for IrPO₄?
iridium(III) phosphate
Which of the following metric prefixes corresponds to 10³?
kilo-
Which of the following metric prefixes corresponds to 10⁶?
mega-
Which of the following is an extensive property of the element carbon?
the mass of an carbon sample (If a property changes based on the amount of sample used, it's extensive. Since mass of a carbon sample changes based on how much carbon you have, it's extensive.)
You measured the mass of a dry powder on a balance to be 23.76 g. What would you report as the uncertainty of this measurement?
± 0.01 (The last digit of a measurement is uncertain and its place value is used in the uncertainty. For example, the 6 in 23.76 is uncertain and found in the hundredths place, yielding an uncertainty measurement of ± 0.01.)
Which of the following describes a chemical change involving water?
CH₂O(l) → H₂(g) + ½O₂(g) A chemical change would involve the atoms found in a water molecule rearranging to form a new molecule or molecules with different composition(s). A physical change would involve the water molecules changing their state of matter but still remaining water molecules. Choice C describes a chemical change.
