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:
5.6 L
Explanation:
We can apply Charles' Law here since our pressure is constant (will not change inside the refrigerator) and we are relating change in volume with change in temperature:
V₁ / T₁ = V₂ / T₂ where V₁ and T₁ are initial volume and temperature, and V₂ and T₂ are final volume and temperature. Let's plug in what we know and solve for the unknown:
28.0 L / 25 °C = V₂ / 5 °C => V₂ = 5.6 L
5.6 L is our new volume (at 5 °C).
I believe your answer is 23.
Credit: answers.yahoo.com
Hope this helps!
Answer:
The answer to your question is Q = 18702.5 J
Explanation:
Data
mass of water = m = 447 g
Cp = 4.184 J/g°C
Temperature 1 = T1 = 25°C
Temperature 2 = T2 = 35°C
Heat = Q = ? Joules
Process
1.- Write the formula to calculate heat
Q = mCp(T2 - T1)
2.- Substitution
Q = (447)(4.184)(35 - 25)
3.- Simplification
Q = (447)(4.184)(10)
4.- Result
Q = 18702.5 J
