Measurement
The base unit for mass
What is the gram
The variable that is measured or observed in an experiment
The dependent variable
Definition of Density:
The ratio of mass to volume.
To be considered accurate, percent error needs to be less than ____%.
10%
How many sig figs are there in 5.896
4
The name of the lab item used to accurately measure the volume of liquids?
graduated cylinder
The name of the variables that are kept the same in an experiment?
What is constants or controlled?
Is density an extensive or intensive property of matter?
Intensive property of matter
A student calculated the density of a sample of copper to be 7.96 g/cm^3. The accepted value is 8.96 g/cm^3. What is the students percent error?
11.2% error
How many sig figs are there in 0.00506900
6
What are the correct units for density?
Grams per milliliter g/mL
The variable that is purposely changed or manipulated by design is called....
The independent variable
What is the density of a block of wood with a mass of 5g and a volume of 20cm3?
.25g/cm3
In an experiment the mass of a sample of citric acid is calculated to be 2.83 g. When the sample is weighed on an electronic balance the actual mass is found to be 2.74 g. What was the student's percent error in their calculation?
3 % error
When adding and subtraction how do you determine how many sig figs the answer should have?
least accurate or least amount of decimal places in the original numbers.
When measuring on a graduated cylinder, always measure at.... ________.
The bottom of the meniscus.
Using the following research question determine the independent and dependent variables:
How does the volume of water (mL) affect the number of days to germinate the tomato seeds?
IV: Volume of water (mL)
DV: Days to germinate tomato seeds (days)
If a rock has a mass of 16.20 g and displaces a 15.0 mL container of water to the 23.6 mark. What is the density of the rock?
1.9 g/mL
In the lab you find that the atomic mass of oxygen in 18.0 amu. In all published texts, the value is 15.99 amu. What is your % error?
13% error
Calculate the answer with the proper sig figs 2.59 s * 6.8 s =?
18 s2
This method can be used to find the volume of an irregular object.
Displacement
Using the following information determine the independent and dependent variables:
One tank of gold fish is fed the normal amount of food once a day. A second tank is fed twice a day. The fish’s weight in grams is recorded daily. All tanks were of the same size and shape.
IV: Number of feedings per day (#/day)
DV: Weight (grams)
If a piece of copper has a density of 8.96 g/cm^3 and when placed into a container weighing 2.9 g creates a mass of 20.7 g. What is the copper's volume?
2.0 cm3
When completing an experiment students are to determine the density of a sample of magnesium. The students know that the density of magnesium is 1.74 g/cm^3. While completing the experiment the students determine the density of the magnesium to be 1.82 g/cm^3. What is the students percent error.
5 % error
Calculate the answer with proper sig figs (1.46 g + 7.801 g + 9.5 g)/2.784mL = ?
6.75 g/mL