Chemistry Unit 1 Review
Find the thickness of a very thin (unmeasureable) layer. Aluminum foil for example.
-Find the volume of the sheet of foil using the m=dv equation. -Take the volume and the divide the width and length from the volume. You will be left with the height/thickness.
Recognize that instruments have a limit to their precision; relate the data recorded to the quality of the measurement.
Estimate only ONE number.
Relate the volume of container (in cm3) to the volume of liquid it contains (in mL).
1cm3=1mL
Mercury has a density of 13.6g/mL. What is the volume occupied by 112.0 grams of mercury.
By using M=DV, I divided the mass by the density (112.0/13.6) to get a volume of 8.24cm3
A cube of gold-colored metal with a volume of 54cm3 has a mass of 980g. The density of gold is 19.3g/cm3. Is this sample of metal pure gold? Why or why not?
By using M=DV, I divided the mass by the volume (980g/54cm3) to get 18g/cm3. So no, this sample isn't pure gold. Although the densities are very close, this cube of metal has a density of 18g/cm3, while real gold's density is 19.3g/cm3 (1.3g/cm3 difference).
Recognize that density is a characteristic property of matter. How can density be used to identify unknown substances.
Density is always going to be the same for one given material. You can also use the formula m=dv
Round off calculated values to the appropriate number of significant figures.
If you're multiplying or dividing, you have to have the same amount of # rounded as the least significant figures. When adding or subtracting you round to the same amount of numbers are the least decimals (15.09+2=17.09, but since 2 has the least amount of decimals, you would round 17.09 to 17).
DENSITY FORMULA !!!!!
M=DV
Given a graph of mass vs volume of a substance, write the equation of the line and state the meaning of this slope.
Slope of 2, y intercept of 0. Formula: y=mx+b (M=slope, B=Y-intercept) ---> 2x+0 Meaning of slope: Density
What is the difference between mass of an object and its volume?
The mass is the amount of stuff in a gram, volume is amount of space the thing takes up in Liters.
A chemistry class produced a histogram to represent the change in mass when sugar was dissolved in water. They concluded that the mass decreases slightly when sugar dissolves. Provide a better explanation.
The mass should have slightly increased after dissolving sugar in the water (increased by the mass of the sugar), but the mass could've decreased from there being water spilled, or another way of removal during dissolving.