Answer:

Explanation:
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In this case, for the given chemical reaction:

We can see a 4:2 mole ratio between lithium nitrate (68.946 g/mol) and lithium sulfate (109.94 g/mol); in such a way, via stoichiometry, the required mass of lithium nitrate to make 250 g of lithium sulfate turns out:

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Answer:
49.95 g of HCl
Explanation:
Let's formulate the chemical equation involved in the process:
Ca(OH)2 + 2 HCl → CaCl2 + 2 H2O
This means that we need 1 mole of Calcium hydroxide to neutralize 2 moles of hydrochloric acid. From this, we calculate the quantity of HCl moles that would be neutralized by 0.685 moles of Ca(OH)2
1 mole Ca(OH)2 ---- 2 moles HCl
0.685 moles Ca(OH)2 ---- x = 1.37 moles HCl
Now that we know the quantity of HCl moles that would react, let's calculate the quantity of grams this moles represent:
1 mole of HCl ---- 36.46094 g
1.37 moles ------ x = 49.95 g of HCl
We need to use the effusion formula. I have attached a picture of what this formula looks like because it is a bit hard to type.
effusion formula---> Rate 1/ rate 2= √(M2/M1)
as the questions states, hydrogen gas rate is 4 times the rate of the other gas. so, let call gas 1 the unknown and gas 2 the hydrogen
Rate 1= 1
Rate 2= 4
M1=??
M2= 2 grams
now let's plug in the values and solve for the unknown
1/4 = √(2/x)
x= 32 grams
with the choices given, the gases are either O₂, N₂ or O₃.
O₂ is the one whose mass is 32 because oxygen atomic mass in the periodic table is 16 grams. since we have two oxygens, then 16 x 2= 32
the answer is "<span>
32 grams and oxygen "</span>