# AP Chemistry

You are given a small bar of an unknown metal X. You find the density of the metal to be 10.5g/cm3. An x-ray diffraction experiment measures the edge of the face-centered cubic unit cell as 4.09 A. (1A=10^-10m) Identify X.

1. 👍
2. 👎
3. 👁
1. a = edge of unit cell = 4.09 Ao = 4.09 x 10^-8 cm.
volume of unit cell = (4.09 x 10^-8 cm)3.

mass = volume x density = volume from last step x 10.5 g/cc = xx g mass/unit cell.

There are 4 atoms per unit cell in a fcc; therefore, xx g/4 = mass of one atom and that times 6.022 x 10^23 atoms/mol = atomic mass of the element. Check my arithmetic; I obtained about 108.1 or so. Look that up on the periodic table to identify the element X.

1. 👍
2. 👎
2. fbfhdfhd

1. 👍
2. 👎

## Similar Questions

1. ### Physics - Buoyant Force

A piece of metal weighs 50.0 N in air, 36.0 N in water, an 41.0 N in an unknown liquid. Find the density of the unknown liquid.

2. ### chemistry

Ima Chemist found the density of Freon-11 (CFCl3) to be 5.58 g/L under her experimental conditions. Her measurements showed that the density of an unknown gas was 4.38 g/L under the same conditions. What is the molar mass of the

3. ### Physics

A manufacturer selected a metal to use in producing a lightweight button for clothing. A metal that has a density of 2.71 g/cm3 was selected. Which of the metals was selected? A Metal 1 B Metal 2 C Metal 3 D Metal 4

4. ### Physics

A bar of aluminum (bar A) is in thermal contact with a bar of iron (bar B) of the same length and area. One end of the compound bar is maintained at Th = 75.5°C while the opposite end is at 30.0°C. Find the temperature at the

1. ### Chemistry

mass of empty flask with stopper = 32.634 g mass of flask with water and stopper = 59.479 g density of the water = 0.9973 g/cm^3 mass of water = 26.845 g volume of water = 26.918 cm^3 the flask is then emptied and an unknown

2. ### Chemistry

Help please: A 0.199-g sample of unknown metal (X) reacts with hydrochloric acid to produce 88.5 mL of "wet" gas at 20 °C and 754 mm Hg. What is the unknown metal (X)? (The vapor pressure of water at 20 °C is 18 mm Hg.) X(s) + 2

3. ### maths

A piece of metal has a volume of 20 cm^3 and a mass of 300g.Calculate the density of the metal in kg/m^3.i got 15.plz confirm my answer.And how does one go about this.2.5 litres of water density 1g/cm^3 is added to 8 litres of

4. ### Physics

A 60-cm-long, 500 g bar rotates in a horizontal plane on an axle that passes through the center of the bar. Compressed air is fed in through the axle, passes through a small hole down the length of the bar, and escapes as air jets

1. ### physics

a piece of metal of density 7800kgm-3 weighs 20N in air. Cal. The apparent weight of th metal when completely immersed in a liquid of density 830kgm-3

2. ### math

A cylindrical metal bar of diameter 14 cm and length 2m is melted and moulded into spherical balls.In the process,5% by volume is lost and what remains makes ball of radius 3.5cm.a)calculate the volume of metal used to make the

3. ### Chemistry

the density of an unknown metal is 2.64 g/cm^3 and its atomic radius is 0.215 nm. It has a face-centered cubic lattice. What is the atomic weight. Answer: 89.4 g/mol how?

4. ### physics

A metal bar has a rectangular cross section 5.0cm by 10cm. The bar has a non-uniform conductivity, and as a result the current density increases linearly from 0 at the bottom to 0.10A/cm^2 at the top. Find the total current in the