Help please Mole Question (1 Viewer)

[TheHoot]

Hey guys,
I have no idea how to even start this question, any help?

What mass of sodium sulfide is needed to precipitate all of the silver (as silver sulfide) from a solution containig 0.033 moles silve nitrate.

Thanks,

 

[adomad]

write a balanced chemical equation

 

[TheHoot]

Na2s + AgNO3 -------->NaNO3 + Ag2s

??? Is that right?

 

[adomad]

seems right... now balance it. lets do it step by step.

start with balancing the metal atoms first, then the non-metals. then hydrogen then oxygen

 

[TheHoot]

Na2S + 2AgNO3 --------> 2NaNO3 + Ag2S

Should be balanced, i think. Now what?

 

[adomad]

awesome. Just a note: if you can't balance an equation, then you got it wrong. since we can balance that one, we got the equation correct.


now we need to calculate the moles of sodium sulfide used in this reaction. if you don't understand, ask. glad to help

fine since you are off line i will just tell u the answer,

from the mole ration... mole of Na2S is 2 X0.033= 0.066 moles

using teh formula n=m/MM. we can work out the mass