Gerri says that spiders use their fangs for the same purpose that crustaceans use their claws. Alana disagrees and says that spiders use their fangs for the same purpose that centipedes use their claws. Which best explains who is correct?

A) Alana is correct because spiders use their fangs to inject venom. Centipedes use their claws for this same purpose.

B) Alana is correct because spiders use their fangs to catch prey. Centipedes use their claws for this same purpose.

C) Gerri is correct because spiders use their fangs to inject venom. Crustaceans use their claws for this same purpose.

D) Gerri is correct because spiders use their fangs to catch prey. Crustaceans use their claws for this same purpose.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

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