Question

name: ervin lopez
assignment: percent error, density, & kmt
1 a student determines the density of a copper sample at room temperature to be 9.46 g/cm³. based on table s, what is the students percent error in determining the density of copper?
1 0.50%
2 5.0%
3 5.3%
4 5.6%
\\(\frac{9.46 - 8.96}{8.96}=5.58\\%\\)
2 at room temperature, a student determines the density of a sample of nickel to be 9.79 g/cm³. based on table s, what is the students percent error for the density of nickel?
1 0.091%
2 0.10%
3 9.1%
4 10.0%
\\(\frac{9.79 - 8.90}{8.90}=10\\%\\)
3 which element has the lowest density at 298 k and 101.3 kpa?
1 argon
2 fluorine
3 nitrogen
4 oxygen
4 a 26.7 - gram sample of which element has a volume of 3.00 cubic centimeters at room temperature?
1 cr
2 cd
3 nb
4 ni
\\(\frac{26.7}{3.00}=8.9\\)
5 which statement describes the particles of an ideal gas, based on the kinetic molecular theory?
1 there are attractive forces between the particles.
2 the particles move in circular paths.
3 the collisions between the particles reduce the total energy of the gas.
4 the volume of the gas particles is negligible compared with the total volume of the gas.
6 according to the kinetic molecular theory, which statement describes the particles in a sample of an ideal gas?
1 the particles are constantly moving in circular paths.
2 the particles collide, decreasing the total energy of the system.
3 the particles have attractive forces between them.
4 the particles are considered to have negligible volume.
7 a student measures the mass and volume of a sample of aluminum at room temperature, and calculates the density of al to be 2.85 grams per cubic centimeter. based on table s, what is the percent error for the students calculated density of al?
1 2.7%
2 5.3%
3 5.6%
4 95%
8 in a laboratory activity, the density of a sample of vanadium is determined to be 6.9 g/cm³ at room temperature. what is the percent error for the determined value?
1 0.15%
2 0.87%
3 13%
4 15%
9 the kinetic molecular theory states that all particles of an ideal gas are
1 colliding without transferring energy
2 in random, constant, straight - line motion
3 arranged in a regular geometric pattern
4 separated by small distances relative to their size

Explanation:

Step1: Recall percent - error formula

Percent error=$\frac{\vert\text{experimental value}-\text{accepted value}\vert}{\text{accepted value}}\times100\%$

Step2: Solve problem 1

The accepted density of copper is 8.96 g/cm³ and the experimental density is 9.46 g/cm³. Percent error =$\frac{\vert9.46 - 8.96\vert}{8.96}\times100\%=\frac{0.5}{8.96}\times100\%\approx5.58\%$.

Step3: Solve problem 2

The accepted density of nickel is 8.90 g/cm³ and the experimental density is 9.79 g/cm³. Percent error=$\frac{\vert9.79 - 8.90\vert}{8.90}\times100\%=\frac{0.89}{8.90}\times100\% = 10\%$.

Step4: Solve problem 3

At 298 K and 101.3 kPa, nitrogen has the lowest density among argon, fluorine, nitrogen and oxygen. Nitrogen is a gas with relatively low - molar mass and exists as $N_2$. Fluorine is a heavier gas ($F_2$), argon is a noble gas with a single - atom structure and higher molar mass than nitrogen, and oxygen ($O_2$) is also heavier than nitrogen.

Step5: Solve problem 4

Density=$\frac{\text{mass}}{\text{volume}}$. Given mass = 26.7 g and volume = 3.00 cm³, density=$\frac{26.7}{3.00}=8.9$ g/cm³. The density of nickel (Ni) is approximately 8.9 g/cm³.

Step6: Solve problem 5

According to the kinetic molecular theory of ideal gases, the volume of the gas particles is negligible compared with the total volume of the gas. There are no attractive forces between the particles, the particles move in straight - line motion until they collide, and the collisions are elastic (total energy is conserved).

Step7: Solve problem 6

According to the kinetic molecular theory, the particles of an ideal gas are considered to have negligible volume.

Step8: Solve problem 7

Assume the accepted density of aluminum is 2.70 g/cm³. Given experimental density = 2.85 g/cm³. Percent error=$\frac{\vert2.85 - 2.70\vert}{2.70}\times100\%=\frac{0.15}{2.70}\times100\%\approx5.6\%$.

Step9: Solve problem 8

Let's assume the accepted density of vanadium is 6.11 g/cm³. Given experimental density = 6.9 g/cm³. Percent error=$\frac{\vert6.9 - 6.11\vert}{6.11}\times100\%=\frac{0.79}{6.11}\times100\%\approx13\%$.

Step10: Solve problem 9

The kinetic molecular theory states that all particles of an ideal gas are in random, constant, straight - line motion.

Answer:

1. 5.58% (closest to option D in problem 1)
2. 10% (option 4 in problem 2)
3. 3. nitrogen (option 3 in problem 3)
4. 4. Ni (option 4 in problem 4)
5. 4. The volume of the gas particles is negligible compared with the total volume of the gas (option 4 in problem 5)
6. 4. The particles are considered to have negligible volume (option 4 in problem 6)
7. 3. 5.6% (option 3 in problem 7)
8. 3. 13% (option 3 in problem 8)
9. 2. in random, constant, straight - line motion (option 2 in problem 9)