(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Twenty grams of silver and gold (total mass of the gold plus the silver is 20 grams) is used to convert 1 g of ice at -3°C to steam at 100°C. If both the silver and the gold are at their melting points at the beginning and the final temperature of the silver, gold and steam is 100°C, what was the individual mass of the silver and the gold?

2. Relevant equations

Q_{1}=Q_{2}

Q=mCpΔT

Q=mL_{vap}

Q=mL_{fus}

3. The attempt at a solution

m_{Au}= x kg

m_{Ag}= (.02-x) kg

m_{ice}= .001 kg

ΔT_{Au}= 1064-100 = 964

ΔT_{Ag}= 962-100 = 862

Cp_{Au}= 130 J/kg[itex]\cdot[/itex]C°

Cp_{Ag}= 230 J/kg[itex]\cdot[/itex]C°

m_{Au}Cp_{Au}ΔT_{Au}+ m_{Ag}Cp_{Ag}ΔT_{Ag}= m_{ice}Cp_{ice}ΔT_{ice}+ m_{ice}L_{fus}+ m_{water}Cp_{water}ΔT_{water}+ m_{water}L_{vap}

x(130)(964) + (0.02-x)(230)(862) = (0.001)(2100)(3) + (0.001)(333) + (0.001)(4186)(100) + (0.001)(2260)

125320x + 3965.2 - 198260x = 6.3 + 0.333 + 418.6 + 2.26

-72940x = -1980.5

x = 0.027 kg

My answer is over 0.02 kg (20g) and because I'm solving for the mass of gold, it was to be less than 20 grams. I've done this problem about four times already and I know I'm doingsomethingwrong, I just can't figure out what.

Any help is greatly appreciated, thank you!!

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# Homework Help: Heat and Energy Transfer Help

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