Question #7e402

2 Answers
Jun 18, 2015

19.49g

Explanation:

2AgF_((aq))+Na_2SO_(4(aq))rarrAg_2SO_(4(s))+2NaF_((aq))2AgF(aq)+Na2SO4(aq)Ag2SO4(s)+2NaF(aq)

c=n/vc=nv

n=cvn=cv

So the number of moles of AgF=AgF=

(2.5xx50.0)/(1000)=0.1252.5×50.01000=0.125

From the equation we can see that 2 moles of AgFAgF produces 1 mole of Ag_2SO_4Ag2SO4

So the no. moles Ag_2SO_4=0.125/2=0.0625Ag2SO4=0.1252=0.0625

The MrMr of Ag_2SO_4=311.8Ag2SO4=311.8

So the mass of Ag_2SO_4=311.8xx0.0625=19.49"g"Ag2SO4=311.8×0.0625=19.49g

Jun 18, 2015

The mass of the precipitate will be equal to 19.5 g.

Explanation:

So, you're two solutions that contain soluble compounds - silver fluoride, AgFAgF, and sodium sulfate, Na_2SO_4Na2SO4.

The double replacement reaction that takes place between these two compounds will produce silver sulfate, Ag_2SO_4Ag2SO4, an insoluble compound, and sodium fluoride, NaFNaF, according to the balanced chemical equation

color(red)(2)AgF_((aq)) + Na_2SO_(4(aq)) -> Ag_2SO_(4(s)) darr + 2NaF_((aq))2AgF(aq)+Na2SO4(aq)Ag2SO4(s)+2NaF(aq)

Since sodium sulfate is in excess, all the moles of silver fluoride will react. The color(red)(2):12:1 mole ratio that exists between silver fluoride and silver sulfate tells you that, regardless of how many moles of the former react, the reaction will produce half as many moles of the latter.

Use the molarity and volume of the silver fluoride solution to determine how many moles take part in the reaction

C = n/V => n = C * VC=nVn=CV

n_(AgF) = "2.50 M" * 50.0 * 10^(-3)"L" = "0.125 moles"nAgF=2.50 M50.0103L=0.125 moles AgFAgF

This means that the reaction will produce

0.125cancel("moles"AgF) * ("1 mole "Ag_2SO_4)/(color(red)(2)cancel("moles"AgF)) = "0.0625 moles" Ag_2SO_4

To get the mass of the precipitate, use its molar mass

0.0625cancel("moles") * "311.8 g"/(1cancel("mole")) = color(green)("19.5 g")

The net ionic equation for this reaction looks like this

2Ag_((aq))^(+) + SO_(4(aq))^(2-) -> Ag_2SO_(4(s)) darr