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 x 10⁸ mm x x = km

Explanation:

Step1: Answer question 1

Cubic centimeter measures volume. So the answer is d. volume.

Step2: Answer question 2

Mass is a property of matter that does not change with appearance change. So the answer is a. mass.

Step3: Answer question 3

When matter changes from liquid to solid, phase energy decreases. So the answer is b. decreases.

Step4: Answer question 4

When matter increases in temperature, thermal energy increases. So the answer is a. increases.

Step5: Answer question 5

First, find the density of the object. Density $
ho=\frac{m}{V}=\frac{21g}{15cm^{3}} = 1.4g/cm^{3}$. Since water density is $1g/cm^{3}$, the object will sink. The initial water - level in the cylinder is not given, assume it is $V_1$. The volume of the object is $V = 15cm^{3}$. The new water - level volume will be $V_2=V_1 + 15cm^{3}$. Sketch the object at the bottom of the cylinder and mark the new water - level accordingly.

Step6: Answer question 6a

We know that $1L = 1000mL$. So to convert $340mL$ to liters, we use the conversion factor $\frac{1L}{1000mL}$. Then $340mL\times\frac{1L}{1000mL}=0.34L$.

Step7: Answer question 6b

We know that $1g = 1000mg$. So to convert $200.5g$ to mg, we use the conversion factor $\frac{1000mg}{1g}$. Then $200.5g\times\frac{1000mg}{1g}=200500mg$.

Step8: Answer question 6c

We know that $1km = 10^{6}mm$. First, convert $1.52\times 10^{8}mm$ to meters: $1.52\times 10^{8}mm\times\frac{1m}{1000mm}=1.52\times 10^{5}m$. Then convert meters to kilometers: $1.52\times 10^{5}m\times\frac{1km}{1000m}=152km$.

Answer:

1. d. volume
2. a. mass
3. b. decreases
4. a. increases
5. Sketch the object at the bottom of the cylinder with new water - level $V_1 + 15cm^{3}$ (where $V_1$ is initial water - level volume).
6. a. $340mL\times\frac{1L}{1000mL}=0.34L$

b. $200.5g\times\frac{1000mg}{1g}=200500mg$
c. $1.52\times 10^{8}mm\times\frac{1m}{1000mm}\times\frac{1km}{1000m}=152km$