Sand build up. Over time, the sand particles As streams flow through Stone Mountain, layers of
form a sedimentar
rock called sandstone.
What causes sandstone to change into metamorphic rock at Stone Mountain?
O Sandstone is reshaped by erosion from a stream.
O Sandstone builds up layers of sand at the mountain.
O Sandstone has more sand particles compacted on top of it.
• Sandstone experiences
Answer c

answer///carbon;

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