Help with this asap please

ΔH rxn = 434.7 kJ

Given

C+O₂⇒CO₂   ΔH=-393.5 (reaction 1)

2CO+O₂⇒2CO₂  ΔH=-566 (reaction 2)

2H₂O⇒2H₂+O₂ ΔH=483.6 (reaction 3)

Required

ΔH rxn

Solution

Reaction 1 : no change

C+O₂⇒CO₂   ΔH=-393.5

Reaction 2 : the reaction is reversed and divided by 2

CO₂⇒ CO+1/2O₂ ΔH=-283

Reaction 3 : divided by 2

H₂O⇒H₂+1/2O₂ ΔH=241.8

C+H₂O⇒CO + H₂ ΔH rxn= -434.7 kJ

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.