Answer:
39.3%
Explanation:
CaF2 + H2SO4 --> CaSO4 + 2HF
We must first determine the limiting reactant, the limiting reactant is the reactant that yields the least number of moles of products. The question explicitly says that H2SO4 is in excess so CaF2 is the limiting reactant hence:
For CaF2;
Number of moles reacted= mass/molar mass
Molar mass of CaF2= 78.07 g/mol
Number of moles reacted= 11g/78.07 g/mol = 0.14 moles of Calcium flouride
Since 1 mole of calcium fluoride yields two moles of 2 moles hydrogen fluoride
0.14 moles of calcium fluoride will yield 0.14×2= 0.28 moles of hydrogen fluoride
Mass of hydrogen fluoride formed (theoretical yield) = number of moles× molar mass
Molar mass of hydrogen fluoride= 20.01 g/mol
Mass of HF= 0.28 moles × 20.01 g/mol= 5.6 g ( theoretical yield of HF)
Actual yield of HF was given in the question as 2.2g
% yield of HF= actual yield/ theoretical yield ×100
%yield of HF= 2.2/5.6 ×100
% yield of HF= 39.3%
Answer:
K₂O
Explanation:
Given parameters:
Mass of K = 36.7g
Mass of O = 7.51g
Unknown:
Empirical formula of the compound
Solution:
The empirical formula of a compound is it's simplest ratio by which the elements in the compound combines. It differs from the molecular formula that shows the actual atomic ratios.
To find the empirical formula, follow this process;
Elements K O
Mass 36.7 7.51
Molar
mass 39 16
Number of
moles 36.7/39 7.51/16
0.94 0.47
Divide by
the smallest 0.94/0.47 0.47/0.47
2 1
Empirical formula is K₂O
The empirical formula of the compound composed of 36.7 g of potassium and 7.51 g of oxygen is K2O.
To determine the empirical formula of a compound, we need to find the ratio of the elements present. In this case, we have 36.7 g of potassium and 7.51 g of oxygen. To find the ratio, we need to convert these masses to moles by dividing them by the molar masses of potassium and oxygen. The molar mass of potassium is 39.10 g/mol and the molar mass of oxygen is 16.00 g/mol. Dividing the masses by the molar masses gives us 0.939 mol potassium and 0.469 mol oxygen. The ratio between these two elements is approximately 2:1, so the empirical formula of the compound is K2O.
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Answer
Density = 7.87g/cm^3
Explanation:
Density is the ratio of mass of the given object to the volume of the object, in this question iron is the given object, then we make use of atomic number of iron
Given:
Length= 287pm = 287*10^-10cm
Atomic mass of Fe= 56.0u
Z=2(for body centered cubic unit cell)
Avogadro number (N 0)=6.022× 10^23
Density= ZM/a^3 × N
Where
Z= body centered cubic unit cell
Then substitute
N= Avogadro's number
a=Length
Density = (2× 56)/(287*10^-10cm)^3 × (6.022 × 10^23)
Density = 7.87g/cm^3
The density of iron in a body-centered cubic unit cell can be calculated using the mass and volume of the unit cell.
The density of iron can be calculated using the formula: density = mass/volume. To determine the mass of the unit cell, we need to know the molar mass of iron and the number of atoms in the unit cell. The molar mass of iron is 55.845 g/mol, and there are two iron atoms in the body-centered cubic unit cell of iron. The volume of the unit cell can be calculated using the formula: volume = (edge length)^3.
Putting these values into the formula, we get:
density = (2 * 55.845 g/mol) / ((287 pm)^3)
Converting the edge length to meters (1 pm = 1e-12 m) and calculating, we find that the density of iron is approximately 7.86 g/cm³.
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b. mmol NaOH Initial concentration of NaOH
c. mL H2O Initial concentration of HCl
Answer:
The following parameters:
Explanation:
The options have been incorrectly arranged in the question statement given here. The three conditions mentioned above are what would be observed to remain the same when this experiment is carried out.
The number of water molecules in a 1.50 mol block of ice is calculated by multiplying the number of moles of water by Avogadro's number. The result is approximately 9.033 x 10^23 water molecules.
In chemistry, the amount of substance in moles is related to the number of particles (atoms, molecules) through Avogadro's number. Avogadro's number, which is 6.022 x 1023 particles/mol, tells us the number of molecules in one mole of a substance.
To calculate the number of water molecules in 1.50 mol of water, you would multiply the number of moles of water by Avogadro's number:
1.50 mol of water x 6.022 x 1023 water molecules/mol of water = 9.033 x 1023 water molecules
Therefore, there are approximately 9.033 x 1023 water molecules in a 1.50 mol block of ice.
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Answer:
- Aluminium sulfate Al2(SO4)3 dissociates in two aluminium ions and three sulfate ions, therefore, van't Hoff factor is 5 (incorrect).
Explanation:
Hello,
In this case, since the van't Hoff factor is related with the species that result from the ionization of a chemical compound, we can see that that
- Aluminium sulfate Al2(SO4)3 dissociates in two aluminium ions and three sulfate ions, therefore, van't Hoff factor is 5 (incorrect).
- Ammonium nitrate NH4NO3 dissociates in one ammonium ions and one nitrate ion, therefore, van't Hoff factor is 2 (correct).
- Sodium sulfate Na2SO4 dissociates in two sodium ions and one sulfate, therefore, van't Hoff factor is 3 (correct).
- Sucrose is not ionized, therefore, van't Hoff factor is 1 (correct).
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Answer:
Explanation:
There are 2.