De la siguiente lista de materiales identifica si corresponde a un elemento, compuesto, mezcla homogénea o mezcla heterogénea:
Acido
acetilsalicílico,
Aire
Azúcar
Bronce
Coctel de frutas
Gasolina
humo de tabaco
oro 14 quilates
ozono
perfume
sal de mesa
sangre
sodio
agua oxigenada
aspirina
tinta
jugó naranja natural
leche entera

lithosphere and asthenosphere

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

the answer your looking for is c).