Calculate the amount of heat energy required to heat up 21.5 grams of ice from -15 °C to 10°C. O -1,870 Joules
3,885 Joules
O 8745 Joules
O 1,870 Joules

a polar bond is formed when electrons are shared unevenly between atoms

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

hypostyle hall;