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# Chemistry questions watch

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1. a.) A 6.22 piece of copper metal is heated from 20.5 degrees C to 324.3 degrees C. Calculate heat absorbed by the metal. Give answer in kJ.

b.) Show the appropriete equations that would allow you to measure the standard heat of formation of Ag2O from elements, Ag and O2. No calculations are necessary.

c.) Calculate the work done when 50.0g of solid tin (Sn) are dissolved in excess acid at 1.00 atm and at 25 degrees C.

Sn + 2H -- Sn^2 + H2

d.) A person drinks four glasses of cold water at 3.0 degrees C every day. The volume of each glass is 2.5 x 10^2 mL. How much heat in kJ does the body have to supply to raise the temp of the water to 37 degrees C, the person's body temp.?
2. I assume you mean 6.22g

(a) 324.3 - 20.5 = heat absorbed = 303.8K
moles of copper = 6.22/63.5 = 0.09796 moles

303.8/0.09796 = 3101.49Kmol^-1

Lol. I don't even know if that's the right form, I just read head absorbed and though give it a try, and use moles while you're at it!
3. (Original post by Jennym0183)
a.) A 6.22 piece of copper metal is heated from 20.5 degrees C to 324.3 degrees C. Calculate heat absorbed by the metal. Give answer in kJ.
Q=mc?T

Need m in kg, c in kJK-¹g-¹ for an answer in kJ.
4. (Original post by Jennym0183)
a.) A 6.22 piece of copper metal is heated from 20.5 degrees C to 324.3 degrees C. Calculate heat absorbed by the metal. Give answer in kJ.

b.) Show the appropriete equations that would allow you to measure the standard heat of formation of Ag2O from elements, Ag and O2. No calculations are necessary.

c.) Calculate the work done when 50.0g of solid tin (Sn) are dissolved in excess acid at 1.00 atm and at 25 degrees C.

Sn + 2H -- Sn^2 + H2

d.) A person drinks four glasses of cold water at 3.0 degrees C every day. The volume of each glass is 2.5 x 10^2 mL. How much heat in kJ does the body have to supply to raise the temp of the water to 37 degrees C, the person's body temp.?
(b) You basically find the enthalpy change of this equation:
2Ag (s) + 1/2 O2 (g) ---> Ag2O (s), which seems to be the same as the standard enthalpy of combustion as silver.

(c) I think you need more data, such as hydration enthalpies, atomisation enthalpies and ionisation enthalpies.

(d) Using q = mc(delta)T, where m is 1 kg per day, the change in temp is 34 and c is 4.2kj per kg, you get q = 142kJ.

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