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:
hi im new because of its solid state
Explanation:
Answer is: a<span> fruit and oatmeal bar contains 142000 calories.
</span>A nutritional calorie<span>, or kilocalorie, is equal to 1000 calories.
</span>E = 142 kcal · 1000 cal/kcal.
E = 142 000 cal.
Calorie (cal)<span>, or small calorie, is the amount of energy needed to heat one gram of water by one degree Celsius.
</span><span>One small calorie is approximately 4.2 joules.
</span>A calorie is a unit of energy.
I think it is halico acid
