2Ag +(aq) + SO4 2-(aq)------>Ag2SO4 (s)
I would say heat, but I might be wrong
Answer:
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Explanation:
To convert from representative particles to moles, Avogadro's Number: 6.02*10²³, which tells us the number of particles (atoms, molecules, etc.) in 1 mole of a substance.
We can use it in a ratio.

Multiply by the given number of molecules.

Flip the ratio so the molecules of water cancel out.


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Divide.
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The original number of molecules has 2 significant figures: 3 and 1, so our answer must have the same. For the number we calculated, that is the tenth place. The 4 in the hundredth place tells us to leave the 1.

There are about 5.1 moles of water in 3.1*10²⁴ molecules of water.
Answer:
3.2 g of O₂
Solution:
This reaction is for the formation of Potassium Superoxide, The reaction is as follow,
K + O₂ → KO₂
First let us confirm that either the given amount of Potassium produces the given amount of Potassium oxide or not,
So,
As,
39.098 g (1 mole) K produced = 71.098 g of K₂O
So,
3.91 g of K will produce = X g of K₂O
Solving for X,
X = (3.91 g × 71.098 g) ÷ 39.098
X = 7.11 g of K₂O
Hence, it is confirmed that we have selected the right equation,
So,
As,
39.098 g of K required = 32 g of O₂
So,
3.91 g of K will require = X g of O₂
Solving for X,
X = (3.91 g × 32 g) ÷ 39.098 g
X = 3.2 g of O₂
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