Atruck was carrying a substance in a tank. the molecules of that substance were moving away from each other. the truck parked overnight in a place where energy transferred out of the substance. in the morning, the substance was a gas. how were the molecules moving in the morning? explain why the molecules were moving that way after energy was transferred out of them.

The molecules are moving away from each other at a slow speed in the morning. The speed is reduced due to the loss of energy.

When the truck was carrying a substance then the molecules are moving away from each other. When molecules are moving away from each other, they are present in the gaseous state. Thus the truck of carrying a gas.

When the truck was parked, the kinetic energy of the molecules decreases. The molecules were gas in nature and energy was transformed out of the substance, they were moving away from each other.

The molecules are able to transfer the energy and lower the temperature. The temperature was not lowered to change the state of the substance. Thus, when the molecules are moving away from each other, the reduction in kinetic energy and loss of energy will slow the speed of the molecules present.

Thus the molecules were moving away from each other at a slow speed. The reduction in speed is because of loss of energy and reduction in kinetic energy.

For more information about energy transfer, refer the link:

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1. In the morning the molecules were moving away from each other with a smaller speed than when the truck was carrying the substance.

2. The reason is that the molecules contain less average kinetic energy, thus their average speed is lower.

Explanation:

Our model of the state (phases) of the substances describes the molecules of solids as not moving away from each other, they are relatively fixed with respect to each other, just vibrating; the molecules of liquids as free to slide pass each other, which permits they to flow, but not moving away from each other; and the the molecules of the gases as moving away from each other, which is the cause of them occupying the whole space of the container that holds them.

According to that, the substance that the truck was carryng was a gas, because the molecules were moving away from each other.

After parking overnight, where energy transferred out of the substance, in the morning, the substance was a gas. Hence, the molecules were moving away from each other too. This answer the first question.

Since energy was transferred out of the substance, in the morning the temperature of the substance decreased (but no enough to make it a liquid). The average kinetic energy of the gases depends only on the temperature. So, the average kinetic energy of the molecules in the morning was smaller than when the truck was carrying the substance. Since the kinetic energy is proportional to the square of the speed of the molecules, the smaller average kinetic energy means that the average speed of the molecules was smaller too. Hence, in the morning the molecules were moving away from each other with a lower speed than when the truck was carrying the substance.

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