A student dissolves 14.6 g of ammonium chloride (NHĻCI) in 200. g of water in a well-insulated open cup. She then observes the temperature of the water fall from 20.0 °C to 15.1 °C over the course of 8.3 minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction:

NH4+ (aq) + Cl- (aq) ----> NH4CI(s)

calculate the amount of heat that was released or absorbed by the reaction in this case kJ per mole of NH4CI

Answer :

baraltoa

Answer:

q = 1.6 x 10⁴ kJ/ mol NH₄CI  

Explanation:

In this question we are given the change in temperature for the dissolution of 14.6 g NH₄Cl. We know from calorimetry that the change in temperature for a mass, m , of water is given by the expression:

q = m x c x Δt

where q is the heat absorbed or released upon dissolution, and c is the specific heat of water.

We have all that is needed to compute q for the dissolution of ammonium chloride, but please note we are being asked the q for the reverse reaction. Thus we would compute q reverse its sign and divide it by the number of moles in 14.6 g NH₄Cl to give the answer this question.

c for H₂O = 4.186 J/g ºC

ΔT = T final - Tinicial = 15.1 ºC - 20.0 ºC =  - 5.10 ºC

q = 200 g x 4.186 J/gºC x  - 5.1 ºC

  =  -4270 J = - 4.3 x 10³ kJ

Thus for the reverse reaction:

NH₄+ (aq) + Cl- (aq) ----> NH₄CI(s)

q = - ( - 4.3 x 10³ kJ ) = 4.3 x 10³ kJ

The molecular weight of  NH₄CI is 53.49 g /mol.

⇒ mol NH₄CI = 14.6 g /53.49 g/mol = 0.27 mol

and the heat absorbed per mol of NH₄CI  , endothermic reaction, is

q = 4.3 x 10³ kJ / 0.27 mol = 1.6 x 10⁴ kJ/ mol NH₄CI  

The heat energy that has been absorbed with the reaction of ammonia and chloride has been 15.36 kJ/mol.

The heat released with the dissolution of the ammonium chloride has been given by:

Heat = mass × specific heat × change in temperature

Mass = 14.6 g

Specific heat = 4.186 J/g[tex]\rm ^\circ C[/tex]

Change in temperature = 15.1 - 20[tex]\rm ^\circ C[/tex]

Change in temperature = -5.1[tex]\rm ^\circ C[/tex]

Heat = 14.6 × 4.186 × -5.1

Heat = -4270 J

Heat = - 4.27 kJ.

The given reaction has been the reversible reaction, thus the absorbed heat for the formation of ammonium chloride has been 4.27 kJ.

This has been the heat for 14.6 grams of ammonium chloride.

Heat per mole can be given by:

Mass of 1-mole ammonium chloride = 53.4 g/mol.

The heat per unit mole has been given as:

14.6 grams = 4.27 kJ

53.4 grams = [tex]\rm \dfrac{4.2}{14.6}\;\times\;53.4[/tex]

= 15.36 kJ

The heat energy that has been absorbed with the reaction of ammonia and chloride has been 15.36 kJ/mol.

For more information about the heat released, refer to the link:

https://brainly.com/question/8828503

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