Question

23. Red lead oxide, Pb304, is used in metal priming paints. It can be made by heating Pbo in air.
6PbO(s) + O2(g) → 2Pb3O4(s)
Which two values are needed to calculate the enthalpy change for this reaction?
Aenthalpy change of combustion of lead and enthalpy change of formation of Pb304 4
Benthalpy change of combustion of PbO and enthalpy change of formation of Pb304
(Centhalpy change of formation of PbO and enthalpy change of atomisation of Oz
Denthalpy change of formation of PbO and enthalpy change of formation of Pb304​

Answer 1

Answer:

see below

Explanation:

First find the gain in energy to the water using => mc(delta)T

therefore 200*4.2*(66-18) = 40320

As mentioned in the question this is 45% only therefore,

45% => 40320

100% => x

using cross multiplication find x

(100*40320)/45

u will get

89600

The question asked to find per gram...! and tht was for 1.6 gram...therefore

1.6 => 89600

1 => x

cross multiply and u get

(1*89600)/1.6 = 56000