Asample of methane at a pressure of 1.00 atm and a temperature of 93.1 k is heated at constant pressure to a temperature of 158 k. which of the following are true? choose all that apply

a. the liquid initially present will solidify.
b. the final state of the substance is a gas.
c. the sample is initially a solid.
d. the sample is initially a liquid. one or more phase changes will occur.

b. The final state of the substance is a gas.

d. The sample is initially a liquid. One or more phase changes will occur.

Explanation:

Methane has the following properties:

*"Normal" refers to normal pressure (1 atm).

According to this, we can affirm:

A sample of methane at a pressure of 1.00 atm and a temperature of 93.1 K is heated at constant pressure to a temperature of 158 K. Which of the following are true? Choose all that apply.

a. The liquid initially present will solidify.  FALSE. The liquid will vaporize.

b. The final state of the substance is a gas.  TRUE.

c. The sample is initially a solid.  FALSE. The sample is initially a liquid.

d. The sample is initially a liquid. One or more phase changes will occur. TRUE.

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