Microbes are so small that they are able to "hide" in the cracks and crevices in your hand even with the help of sanitizer it only kills 99% not 100% so font dump that soap yet because you'll be wanting to kill that 1% that is causing you disease and fermintation
I'm pretty sure that it's either 83.2% or 91.4%
1) ionic compound
there should be motive ions or free movable electrons to conduct electricity. The ionic compounds in the solid state, has no motive ions or free electrons as the ions are tightly attracted to each other. But in liquid state, the ions separate and move freely.
A) Limiting reactant
You need the molar ratios (from the balanced chemical equation) and the molar masses of each compound (from the atomic masses)
a) Molar ratios:
6 mol HF : 1 mol SiO2 : 1 mol H2SiF6
2) Molar masses:
Atomic masses:
H: 1 g/mol
F: 19 g/mol
Si: 28 g/mol
O: 16g/mol
=>
HF:1g/mol + 19 g/mol = 20 g/mol
SiO2: 28g/mol + 2*16g/mol = 60 g/mol
H2SiF6: 2*1g/mol + 28g/mol + 6*19g/mol = 144g/mol
3) convert data in grams to moles
21.0 g SiO2 / 60 g/mol = 0.35 mol SiO2
70.5 g HF / 20 g/mol = 3.525 mol HF
4) Use the theorical ratios to deduce which is in excess and which is the limiting reactant.
6 mol HF / 1mol SiO2 < 3.525 mol HF / 0.35 mol SiO2 ≈ 10
=> There is more HF than the needed to react with 0.35mol of SiO2 =>
SiO2 is the limiting reactant (HF is in excess)
b) Mass of excess reactant.
1) Calculate how many grams reacted, which requires to calculate first the number of moles that reacted
0.35 mol SiO2 * 6 mol HF / 1 mol SiO2 = 2.1 mol of HF
2.1 mol HF * 20 g/mol = 42 gram of HF
2) Subtract the quantity that reacted from the original quantity:
70.5 g - 42 g = 28.5 g of HF in excess
c) Theoretical yield of H2SiF6
1 mol of SiO2 ; 1 mol of H2SiF6 => 0.35 mol SiO2 : 0.35 mol H2SiF6
Convert those moles to grams: 0.35 mol * 144 g/mol = 50.4 grams
d) % yield
% yield = actual yield / theoretical yield * 100 = 45.8 / 50.4 * 100 = 90.87%
The correct answers :
It increases with a decrease in the concentration of H₂(g).
It decreases with an increase in the concentration of S₂(g).
It decreases with an increase in the concentration of H₂(g).
<h3 /><h3>Further explanation</h3>
Forward reaction : rate to form product
In equilibrium :
The product decreases ⇒ system will move from left to right(forward reaction)
The product increases ⇒ system will move from right to left(reverse reaction)
