Answer:
A. Move the buret clamp to a ring stand with a larger base.
Explanation:
The ring stands are used to hold burettes, light in weight to avoid loss of stability, that is why it is necessary to change the size of the ring stand so that it can support the buret that we are going to use. It is not recommended to balance it with the hand since it would give us an inaccurate result in the titration.
Here's my best guess
the volume of the unit cell is (385*10^-12)^3=5.7066*10^-29 m^3
multiply by density to get mass
mass = (7 g/cm^3)*(100^3 cm^3 / 1^3 m^3) * 5.7066*10^-29 m^3= 3.99466*10^-22 g
covert to moles
3.99466*10^-22 g * 1 mol / 239.82 g = 1.6657 *10^-24 mol
convert to number of units
1.6657 *10^-24 mol * 6.23*10^23 units/mol = 1.04
385 pm = 3.85*10^(-8) cm
The volume of the unit cell is the cube of that, which is 5.71*10^(-23) cm^3. Since the ratio of mass to volume (i.e. the density) must be the same no matter what amount of TlCl you have, you can say:
7 = x/(5.71*10^(-23)), where x is the mass of the unit cell. Solving for x, you get 4*10^(-22) g.
The mass of a molecule of TlCl is 240 amu, which in grams is 4*10^(-22) g. The mass of the unit cell and the mass of a molecule of TlCl is the same. Therefore there is one formula unit of TlCl per unit cell.
Well it breaks down into small parts
Answer:
location of an earthquake's epicenter
Explanation:
There are two pieces of evidence that help scientists to learn and explore the Earth's interior. The first type of evidence is direct evidence and the other type is indirect evidence. The rock samples and the composition of the rocks belong to the direct evidence group while the evidence from the seismic waves and their observations belong to the indirect evidence. Seismic waves help the geologists to understand the Earth's interior.
1) State the equation that represents the chemical reaction
P2O5 + 3H2O → 2H3PO4
2) State the molar ratios: 1 mol P2O5 : 3 mol H2O : 2 mol H3PO4
3) Use the proportions 3molH2O / 2 mol H3PO4
0.729 mol H3PO4 * [ 3 mol H2O / 2 mol H3PO4] = 1.094 mol H2O
Answer: 1.094 mol of water
