Question

chemistry - unit 1 test

1. cubic centimeter is a unit used to measure

a. mass b. area c. weight d. volume

1. what property of matter does not change even though the appearance may change?

a. mass b. area c. shape d. volume

1. when matter changes from liquid to solid, phase energy...

a. increases b. decreases c. stays the same

1. when matter increases in temperature, thermal energy...

a. increases b. decreases c. stays the same

1. above is a cylinder containing water. an object with a mass of 21g and a volume of 15 cm³ is lowered into the water. sketch the object and the new water level in the cylinder on the right.
2. use the dimensional - analysis method to make the following conversions (be sure to keep the appropriate number of sfs)

a. 340 ml x = liters
b. 200.5 g x = mg
c. 1.52×10⁸ mm x x = km

Explanation:

Step1: Answer question 1

Cubic centimeter measures volume.

Step2: Answer question 2

Mass is the property that doesn't change with appearance change.

Step3: Answer question 3

When matter changes from liquid to solid, phase energy decreases.

Step4: Answer question 4

When matter increases in temperature, thermal energy increases.

Step5: Answer question 5

First, find the density of the object: $
ho=\frac{m}{V}=\frac{21g}{15cm^{3}} = 1.4g/cm^{3}$. Since the density of water is approximately $1g/cm^{3}$, the object will sink. The initial water - level is not given, assume it is at $30mL$ (from the cylinder drawing). The volume of the object is $15cm^{3}=15mL$. The new water - level will be at $30 + 15=45mL$. Sketch the object at the bottom of the cylinder and mark the new water - level at $45mL$.

Step6: Answer question 6a

Use the conversion factor $1L = 1000mL$. So, $340mL\times\frac{1L}{1000mL}=0.34L$.

Step7: Answer question 6b

Use the conversion factor $1g = 1000mg$. So, $200.5g\times\frac{1000mg}{1g}=200500mg$.

Step8: Answer question 6c

Use the conversion factors $1km = 10^{6}mm$. So, $1.52\times10^{8}mm\times\frac{1m}{1000mm}\times\frac{1km}{1000m}=152km$.

Answer:

1. d. volume
2. a. mass
3. b. decreases
4. a. increases
5. Sketch object at bottom, new water - level at 45mL (assuming initial level at 30mL)
6. a. $340mL\times\frac{1L}{1000mL}=0.34L$

b. $200.5g\times\frac{1000mg}{1g}=200500mg$
c. $1.52\times10^{8}mm\times\frac{1m}{1000mm}\times\frac{1km}{1000m}=152km$