Plants adapted to store can survive the of the savanna dry season. Many and short trees with far-reaching inhabit this biome

Explanation:

Plants adapted to store water for long periods can survive the droughts and arid heat of the savanna dry season. Many xerophytes, such as cacti and short trees with far-reaching roots inhabit this biome.

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