Substance and Properties
This term defines a pure substance that is made of only one type of atom.
An element
What is the symbol for the prefix nano, and what is its numerical value in scientific notation?
n, and 10−9
How many pounds is a 1.61 kg high school boys’ discus? (1 kg = 2.2 lbs)
3.542 lbs
What is the difference between accuracy and precision?
Accuracy is how close a measurement is to the true value, while precision is how close multiple measurements are to each other.
What is the Law of Conservation of Mass?
Mass is neither created nor destroyed during a chemical reaction.
This type of property depends on the amount of substance present, such as mass or volume.
Extensive
Convert 295 K into Celsius.
22 °C (295−273.15)
A runner travels at 7 m/s. How far will they travel in 1 minute?
420 m
A scale reads 48.7 g for a 50.0 g cylinder. What is the scale's percent error?
2.6% (Percent error = 50.0∣48.7−50.0∣×100%)
If 2.1 g of nitrogen react with 2.4 g of oxygen to form nitric oxide, what is the mass of the nitric oxide formed?
4.5 g
What type of change is the melting of ice? Why?
Physical. Same compound.
Convert 51 nanograms (ng) to grams (g).
5.1×10−8 g
A block of granite has a mass of 15 kg. Given that its density is 2.75 kg/L, what is its volume?
5.45 L
What are some common measures for accuracy and precision?
Accuracy is commonly measured by percent error, while precision is measured by standard deviation or range.
This law states that a compound always contains the same proportion of its elements by mass.
The Law of Definite Proportions
Explain the difference between a homogeneous mixture and a compound.
A homogeneous mixture can be physically separated, while a compound can only be separated into elements through a chemical reaction.
Convert 0.22 decigrams (dg) to kilograms (kg).
2.2×10−5 kg
Atoms in a sheet of graphene are 0.142 nm apart. Given that there are 3.28 ft in 1 m, what is this distance in feet?
4.66×10−10 ft
Explain why range is not always the best measure of precision.
Range only considers the two extreme values and doesn't account for how the other data points are distributed, which can be misleading
How many grams of potassium should be in a 55.00 g sample of potassium chloride if a 20.00 g sample contains 10.49 g of potassium?
28.85 g
Classify each of the following as an element, a compound, or a mixture: Iron, maple syrup, and baking soda
Element, mixture, compound
A substance has a mass of 1.5 kilograms. If this mass is also equal to 1,500,000 micrograms, what is the numerical value for the micro prefix?
10−6
Gas in the UK costs £1.27/L. Given that there are 3.79 L in a gallon and £1 is worth $$1.32$, how much would it cost in dollars to fill a 13-gallon tank?
83.56
A scientist attempts to calibrate their scale by measuring the mass of a metal cylinder with a known mass of 50.0 g. If the scale’s measurement of the mass is 48.7 g, determine the scale’s percent error.
2.6%
Consider three samples containing nitrogen and oxygen. Sample A has a mass ratio of 1.75 g O to 1.0 g N. Sample B has a mass ratio of 1.17 g O to 1.0 g N. Sample C has a mass ratio of 2.33 g O to 1.0 g N. How many different compounds are represented here, and which law is this an example of?
There are three different compounds, which is an example of the Law of Multiple Proportions.