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3 years ago

How do you find the average density?

Chemistry

1 answer:

photoshop1234 [79]3 years ago

3 0

Answer:

total mass divided by its total volume

Explanation:

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3. Crystalline structural unit of barium metal is a body-centered cubic cell. The edge length of the unit cell is 5.02x10-8 cm.

tiny-mole [99]

Answer:

The Avogadro's number is $N_A = 6.02289 *10^{23}$

Explanation:

From the question we are told that

The edge length is $L = 5.02 * 10^{-8} \ cm= \frac{5.02 * 10^{-8} }{100} = 5.02 * 10^{-10}$

The density of the metal is $\rho = 5.30\ g/cm^3 = 5.30 * \frac{g}{cm^3} * \frac{1*10^6}{1*10^3} = 5.30 *10^3kg/m^3$

The molar mass of Ba is $Z = 137.3 \ g/mol = \frac{137.3}{1000} = 0.1373 \ kg / mol$

Generally the volume of a unit cell is

$V = L^3$

substituting value

$V = [5.02 *10^{-10}]^3$

$V = 1.265*10^{-28}\ m^3$

From the question we are told that 68% of the unit cell is occupied by Ba atoms and that the structure is a metal which implies that the crystalline structure will be (BCC),

The volume of barium atom is

$V_a = \frac{V}{2} * 0.68$

substituting value

$V_a = \frac{ 1.265*10^{-28}}{2} * 0.68$

$V_a = 4.301 *10^{-29} \ m^3$

The Molar mass of barium is mathematically represented as

$Z = N_A V_a * \rho$

Where $N_A$ is the Avogadro's number

$N_A = \frac{ Z}{ V_a * \rho}$

substituting value

$N_A = \frac{ 0.1373}{ 4.301*10^{-29} * 5.3*10^{3}}$

$N_A = 6.02289 *10^{23}$

4 0

2 years ago

Matt's cube, after 5 trial, had an average destiny of 7.40. g/cm what is it made of ?

alekssr [168]

Explanation:

5 trial, had an average destiny of 7.40. g/cm

4 0

2 years ago

In a mixture of 2 ideal gases, A and B, PA = 0.2PB, what is the mole fraction of A?

Alborosie

Answer:

0.1667

Explanation:

Hello,

Dalton's law defines:

$y_i=\frac{P_i}{P_T}$

A total pressure is:

$P_T=P_A+P_B$

So, for A (solving for $P_A$ in the previous equation, we get:

$y_A=\frac{P_A}{P_A+P_B}$

Since $P_A=0.2P_B$ , we obtain:

$y_A=\frac{P_A}{P_A+P_A/0.2}\\y_A=\frac{1}{6}\\y_A=0.1667$ }

Best regards.

7 0

3 years ago

Which of the following is true: A. Gamma rays are too dangerous to be used in a medicinal way. B. Gamma radiation is used common

ratelena [41]

Answer:

Explanation:

Gamma radiation penetrates the cell wall of prokaryotic organisms such as bacteria and can inhibit their metabolic functions as well as destroy their DNA.

Debunking the other answers:

A is incorrect as Gamma radiation is used in the treatment of cancer via radiotherapy.

B is incorrect as Gamma rays are too small and would just penetrate any smoke particles.

C is incorrect because Gamma rays are used to disinfect food products to prevent food borne illness. Irradiation is safe to use on food and does not make it radioactive.

Thus, D is correct.

6 0

1 year ago

describe the independent and dependent variables in this experiment then describe the other variables that need to be controlled

uranmaximum [27]

independent variable is being controlled and the dependent variable is being tested and being easured in a scientific experiment

3 0

2 years ago