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:
um
Explanation:
help you? you mean do it for you? nah man you can just use the calculator ;)
What biochemical reaction??
Answer:
Diluted concentration is 0.5M
Explanation:
Let's solve this with rules of three, although there is a formula to see it easier
In 1000 mL (1L), we have 2 moles of NaOH
In 250 mL we must have (250 . 2) / 1000 = 0.5 moles of NaOH
These moles will be also in 1 L of the final volume of the diluted solution
More easy:
1 L of solution has 0.5 moles of NaOH
Then, molarity is 0.5 M
The formula is: Concentrated M . Conc. volume = Diluted M . Diluted volume
2 M . 0.250L = 1L . Diluted M
0.5M = Diluted M
1. 
- The changing of liquid to a gas.
2. 
- The major source of pollution.
3. 
- Carbon dioxide and water vapor trapping heat given off by Earth.
4. 
- Layer absorbing ultraviolet rays.
5. 
- The changing of a gas to a liquid.
6. 
- Layer responsible for reflecting radio waves.
7. 
- The layer in which weather changes.
