Answer:
Molecular formula → PbSO₄ → Lead sulfate
Option c.
Explanation:
The % percent composition indicates that in 100 g of compound we have:
68.3 g of Pb, 10.6 g of S and (100 - 68.3 - 10.6) = 21.1 g of O
We divide each element by the molar mass:
68.3 g Pb / 207.2 g/mol = 0.329 moles Pb
10.6 g S / 32.06 g/mol = 0.331 moles S
21.1 g O / 16 g/mol = 1.32 moles O
We divide each mol by the lowest value to determine, the molecular formula
0.329 / 0.329 = 1 Pb
0.331 / 0.329 = 1 S
1.32 / 0.329 = 4 O
Molecular formula → PbSO₄ → Lead sulfate
Answer:
- 0.0249% Sb/cm
Explanation:
Given that:
One surface contains 1 Sb atom per 10⁸ Si atoms and the other surface contains 500 Sb atoms per 10⁸ Si atoms.
The concentration gradient in atomic percent (%) Sb per cm can be calculated as follows:
The difference in concentration = 
The distance 
= 0.2-mm = 0.02 cm
Now, the concentration of silicon at one surface containing 1 Sb atom per 10⁸ silicon atoms and at the outer surface that has 500 Sb atom per 10⁸ silicon atoms can be calculated as follows:
= - 0.0249% Sb/cm
b) The concentration 
of Sb in atom/cm³ for the surface of 1 Sb atoms can be calculated by using the formula:
Lattice parameter = 5.4307 Å; To cm ; we have
= 
= 
The concentration 
of Sb in atom/cm³ for the surface of 500 Sb can be calculated as follows:
= 
= 
Finally, to calculate the concentration gradient
Depression is freezing point is a colligative property. It is mathematically expressed as ΔTf = Kf X m
where Kf = <span>freezing point depression constant = 1.86°c kg /mol (for water)
m = molality of solution = 1.40 m
</span>∴ ΔTf = Kf X m = 1.86 X 1.40 = 2.604 oC
Now, for water freezing point = 0 oC
∴Freezing point of solution = -2.604 oC
Answer:
Pb(NO3)2
Cd(NO3)2
Na2SO4
Explanation:
In the first part, addition of HCl leads to the formation of PbCl2 which is poorly soluble in water. This is the first precipitate that is filtered off.
When the pH is adjusted to 1 and H2S is bubbled in, CdS is formed. This is the second precipitate that is filtered off.
After this precipitate has been filtered off and the pH is adjusted to 8, addition of H2S and (NH4)2HPO4 does not lead to the formation of any other precipitate.
The yellow flame colour indicates the presence of Na^+ which must come from the presence of Na2SO4.
Answer:
Another view could be from this definition: (Electron Sea Model) : The metallic bond consists of a series of metals atoms that have all donated their valence electrons to an electron cloud that permeates the structure. This electron cloud is frequently referred to as an electron sea. It might help to visualize the electron sea model as if it were a box of marbles that are surrounded by water. The marbles represent the metal atoms and the water represents the electron sea.
Explanation:
