Question

A student determines the heat of dissolution of solid ammonium bromide using a coffee-cup calorimeter of...

A student determines the heat of dissolution of solid ammonium bromide using a coffee-cup calorimeter of negligible heat capacity.

When 6.34 g of NH4Br(s) is dissolved in 119.00 g of water, the temperature of the solution drops from 25.00 to 22.76 °C. Based on the student's observation, calculate the enthalpy of dissolution of NH4Br(s) in kJ/mol. Assume the specific heat of the solution is 4.184 J/g°C.

ΔHdissolution =  kJ/mol

Homework Answers

Answer #1

no of moles of NH4Br   = W/G.M.Wt

                                     = 6.34/97.94   = 0.0647moles

mass of solution   = 6.34+ 119   = 125.34g

q = mcT

      = 125.34*4.184*(22.76-25)

        = -1174.7J

ΔHdissolution      = -1174.7J

                           = -1174.7/0.0647   = -18.156KJ/mole   >>>>>answer

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The salt calcium bromide is soluble in water. When 1.48 g of CaBr2 is dissolved in...
The salt calcium bromide is soluble in water. When 1.48 g of CaBr2 is dissolved in 112.00 g of water, the temperature of the solution increases from 25.00 to 26.56 °C. Based on this observation, calculate the enthalpy of dissolution of CaBr2 (in kJ/mol). Assume that the specific heat of the solution is 4.184 J/g °C and that the heat absorbed by the calorimeter is negligible. ΔHdissolution =  kJ/mol
The salt cesium bromide is soluble in water. When 9.28 g of CsBr is dissolved in...
The salt cesium bromide is soluble in water. When 9.28 g of CsBr is dissolved in 115.00 g of water, the temperature of the solution decreases from 25.00 to 22.72 °C. Based on this observation, calculate the enthalpy of dissolution of CsBr (in kJ/mol). Assume that the specific heat of the solution is 4.184 J/g °C and that the heat absorbed by the calorimeter is negligible. ΔHdissolution =  kJ/mol
1. When a solid dissolves in water, heat may be evolved or absorbed. The heat of...
1. When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution (dissolving) can be determined using a coffee cup calorimeter. In the laboratory a general chemistry student finds that when 6.20 g of CsClO4(s) are dissolved in 115.60 g of water, the temperature of the solution drops from 22.87 to 19.50 °C. Based on the student's observation, calculate the enthalpy of dissolution of CsClO4(s) in kJ/mol. Assume the specific heat of the solution is...
When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution...
When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution (dissolving) can be determined using a coffee cup calorimeter. In the laboratory a general chemistry student finds that when 4.13 g of CuCl2(s) are dissolved in 111.70 g of water, the temperature of the solution increases from 25.33 to 28.58 °C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.89 J/°C....
When 4.93 g of ammonium bromide (NH4Br) is dissolved in 103 g of water in a...
When 4.93 g of ammonium bromide (NH4Br) is dissolved in 103 g of water in a styrofoam calorimeter of negligible heat capacity, the temperature drops from 25.00 to 22.97 °C. Based on this observation, calculate q for the water and ΔH° for the process, assuming that the heat absorbed by the salt is negligible. NH4Br(s) NH4+(aq) + Br- (aq) The specific heat of water is 4.184 J °C-1 g-1.
When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution...
When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution (dissolving) can be determined using a coffee cup calorimeter. In the laboratory a general chemistry student finds that when 18.53 g of Cs2SO4(s) are dissolved in 100.40 g of water, the temperature of the solution drops from 25.54 to 22.92 °C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.85 J/°C....
When a solid dissolves in water, the solution may become hotter or colder. The dissolution enthalpy...
When a solid dissolves in water, the solution may become hotter or colder. The dissolution enthalpy (dissolving) can be determined using a coffee cup calorimeter. In the laboratory a general chemistry student finds that when 10.13 g K2SO4(s) is dissolved in 114.80 g water, the temperature of the solution drops from 24.11 to 20.86 °C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.77 J/°C. Based on...
A coffee cup calorimeter initially contains 125g of water at 24.2oC. 10.5g of potassium bromide also...
A coffee cup calorimeter initially contains 125g of water at 24.2oC. 10.5g of potassium bromide also at 24.2oC is added to the water. After the KBr dissolves the final temperature is 21.1oC. Calculate the enthalpy change for dissolving the salt in J/g and kJ/mol. Assume specific heat of solution is 4.18J/goC.
A coffee-cup calorimeter initially contains 125 g water at 24.2 degrees celsius. Ammonium Nitrate (10.5 g),...
A coffee-cup calorimeter initially contains 125 g water at 24.2 degrees celsius. Ammonium Nitrate (10.5 g), also at 24.2 degree celsius, is added to the water, and after the ammonium nitrate dissolves, the final temperature is 18.3 degrees celsius.What is the heat of solution of ammonium nitrate in kj/mol? Assume that the specific heat capacity of the solution is 4.18 J/Cg and that no heat is transferred to the surrounds or to the calorimeter.
When 10.0 g KOH is dissolved in 100.0 g of water in a coffee-cup calorimeter, the...
When 10.0 g KOH is dissolved in 100.0 g of water in a coffee-cup calorimeter, the temperature rises from 25.18 ˚C to 47.53 ˚C. Calculate the ∆Hrxn for the dissolution process. Assume that the solution has a specific heat capacity of 4.184 J/gK
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT