1.
Density can be defined as the mass of the substance in unit volume.
Density = mass / volume
Hence, g/mL and kg/L can be used as the units of density.
Those units are interchangeable because when converting one unit into other one nothing will happen to the value.
That is because when converting the g into kg, you have to multiply the value by 1 x 10⁻³. When converting mL into L, you should again multiply the volume by 1 x 10⁻³. Then those 1 x 10⁻³ will cancel off and the original value will remain as same.
2.
Answer is 2.70 g/mL.
<em>Explanation;</em>
Mass of the block = 146 g
Volume of the block = length x width x height
= 6.0 cm x 3.0 cm x 3.0 cm
= 54 cm³ = 54 mL
Density = mass / volume
= 146 g / 54 mL
= 2.70 g/mL
3.
Answer is 3.39 g/mL.
<em>Explanation;</em>
When immersing an object in a solution, the increased volume indicates the volume of that object.
Hence,
Volume of the object = increased volume of water level
= final volume - initial volume
= 27.8 mL - 21.2 mL
= 6.6 mL
Mass of the object = 22.4 g
Density = Mass / Volume
= 22.4 g / 6.6 mL
= 3.39 g/mL
4.
Accepted value is the value that scientists and community accept as true. This is a theoretical value.
But the measured value is the value that you obtain from doing experiments. This is the actual value.
If your measured value is more close to the accepted value, then your measured value is more precise. But, if your measured value is far away from accepted value means that your value is not precise and there may have some errors.
5.
Answers : Percent error is 9.11 %
The element which has 7.13 g/cm³ as density is Zinc (Zn).
<em>Explanation;</em>
Percent error can be calculated by using following formula.
% error = ( (measured value - accepted value) / accepted value ) x 100%
= ( (7.78 g/cm³ - 7.13 g/cm³) / 7.13 g/cm³ ) x 100%
= 9.11 %
![pH=-log[H^{+}]=-log[H_{3}O]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%7B%2B%7D%5D%3D-log%5BH_%7B3%7DO%5D%20%20)
. Using the value in formula, we get:![pH=-log[1.8*10^{-4}]=3.745](https://tex.z-dn.net/?f=pH%3D-log%5B1.8%2A10%5E%7B-4%7D%5D%3D3.745%20)