Question

HWW Item 810

Part A

Titanium reacts with iodine to form titanium(III)iodide, emitting heat.
2Ti(s)+3I2(g)→2TiI3(s)ΔHorxn = -839 kJ

Determine the masses of titanium and iodine that react if 1.50×10³ kJ of heat is emitted by the reaction.Express your answer to three significant figures and include the appropriate units.

m(Ti)= (value)(unit)

m(I2)= (value)(unit)

Part B

Consider the following generic reaction: A+2B→C+3D, with ΔH = 128 kJ . Determine the value of ΔH for each of the following related reactions.

a) 3A+6B→3C+9D

ΔH = _____ kJ

b) C+3D→A+2B

ΔH = _____ kJ

c) 1/2C+3/2D→1/2A+B

ΔH = _____ kJ

Answer 1

A)

2Ti_(s)     +     3I₂(g)       →          2TiI_3(s)        ΔH^o_rxn = -839 kJ

Using intary comparison, we can find the moles,

839 kJ energy is released when, 1 mole reaction occurs

for 1 Kj energy to be released, Moles = 1/839 mole

for 1500 KJ energy to be released, Moles = (1/839)x1500 = 1.7878 mole reaction

It means that

: Moles of Ti = 1.7878x2 moles = 3.57 moles => Mass of Ti = 3.57x47.86 =171.132 gram

Moles of I₂= 1.7878x3 moles = 5.363 moles => Mass of I2 = 5.363x254 =1362.30 gram

B) The enthapy of reaction changes according to the stiochiometry of the reaction.

The factor with which you chnage the reaction stiochiometry same applies to the enthapy of reaction

a) 3A+6B→3C+9D    factor of 3

ΔH = 3x 128 = 384 kJ

b) C+3D→A+2B    factor of -1

ΔH = -128 kJ

c) 1/2C+3/2D→1/2A+B   factor of -1/2

ΔH = -1/2(128)= -64 kJ