Mendeleev's Mind-Benders
A runner runs 4875 ft in 6.85 minutes. What is the runner’s average speed in miles per hour?
8.09 mi/hr
What is the mass of 225 mL of a liquid that has a density of 0.880 g/mL?
198 g
A marathon is 26.2 miles from start to finish. Convert this distance from miles to kilometers (1km =0.621 miles)
What is 42.2 kilometers.
Why is the fundamental value of a quantity not changed when the quantity is multiplied by a conversion factor?
The quantity remains the same because a conversion factor is a ratio that represents the same value in two different units.
A fish tank has a capacity of 1200 milliliters. How many liters of water can it hold?
What is 1.2 liters?
An automobile travels 97.2 km on 7.88 L of gasoline. What is the gas mileage for the automobile in miles per gallon?
29.0 mi/gal
What is the edge length of a 155-g iron cube? (density of iron is 7.86 g/cm^3)
2.70 cm
An automobile travels 28.0 miles (mi) on a gallon (gal) of gasoline. How far (in miles) can the automobile travel on 25.0 liters (L) of gas
What is 184.3 miles?
Write conversion factors for each:
miles to kilometers
kilometers to miles
gallons to liters
liters to gallons
1 mile =1.609 kilometers
1 kilometer = 0.6214 miles
1 gallon =3.785 liters
1 liter =0.264172 gallons
In a cooking recipe, it calls for 250 milliliters of olive oil. Convert this to liters.
What is 0.25 liters?
Convert 876.9 in ^3 to m^3
0.01437 m^3
Explain why units are important in a calculation
Units act as a guide in the calculation and are able to show if the calculation is off track.
Convert 500 milliliters of a solution to liters
What is 0.5 liters?
Experienced problem solvers always consider both the value and units of their answer to a problem. Why?
In multiple-step problems it is easy for errors to creep into the solution. By checking your answer and making sure the value makes sense and has the correct units, you can catch most errors.
Your favorite soda comes in a 355-milliliter can. How many liters of soda is in one can?
What is 0.355 liters?
Convert 27 m/s to km/hr
97 km/hr
How are units treated in a calculation?
Units are treated exactly the same as numbers in calculations and can be multiplied, divided, and canceled.
Convert 2.5 liters of gas to milliliters.
2500 milliliters
What is density?
How much space an object or substance takes up (its volume) in relation to the amount of matter in that object or substance (its mass).
A chemistry experiment requires 450 milliliters of a solution. How many liters is this?
What is 0.45 liters?
A cube measures 2.5 cm on each edge and has a mass of 66.9 g. Calculate the density of the material that composes the cube.
4.3 g/cm^3
What is a conversion factor?
A conversion factor is a fraction composed of two equivalent quantities and is used to convert information from one set of units to another.
The density of a liquid is 1.2 g/mL. What is the mass of 250 mL of this liquid
300 grams
Explain how you would calculate the density of a substance.
By using the equation density = mass/volume or d = m/v.
If a swimming pool contains 1500 milliliters of water, how many liters is that?
What is 1.5 liters?