Ask question

Ask question

All categories

3 years ago

8

Question 1 the heat of vaporization δhv of dichloromethane ch2cl2 is 28.0 /kjmol . calculate the change in entropy δs when 210.g

of dichloromethane condenses at 39.8°c . be sure your answer contains a unit symbol and the correct number of significant digits.

1 answer:

N76 [4]3 years ago

8 0

The answer is 39.933*C

You might be interested in

Which statement describes the differences between nuclear reactions and chemical reactions?

bearhunter [10]

Chemical reactions are a change in substance while nuclear is destruction

6 0

3 years ago

You are given a solution of sugar and sand and water your task is to separate sugar from sand which of the following experimenta

Ostrovityanka [42]

Answer:

Explanation:

Filtration followed by evaporation:

To separate the mixture of sand and sugar, it is best to use the separation technique of filtration then evaporation.

Pour the water into the mixture. The sugar will dissolve with time in the water. Sand is made up of quartz and does not dissolve in water.

After the dissolution, filter the solution to separate the sand using a filter paper.

Dry the sand thereafter then proceed to evaporate the sugar with water solution. Evaporation will turn water into vapor and the sugar crystals will be left behind.

8 0

3 years ago

In an ion with an unknown charge, the total mass of all the electrons was determined to be 2.19 ✕ 10−26 g, while the total mass

Ilya [14]

Answer:

$\large \boxed{\text{Fe$^{{2+}}$}}$

Explanation:

1. Number of electrons

$\text{Number of electrons} = 2.19 \times 10^{-26}\text{ g} \times \dfrac{\text{1 electron}}{9.109 \times 10^{-28}\text{ g}} = \text{24 electrons}$

2. Number of protons

$\text{Number of protons} = 4.34 \times 10^{-23}\text{ g} \times \dfrac{\text{1 proton}}{1.673 \times 10^{-24}\text{ g}} = \text{26 protons}$

3. Identify the ion

An atom with 26 protons is iron, Fe.

A neutral atom of iron would have 26 electrons.

The ion has only 24 electrons, so it has lost two. The ion must have a charge of +2.

$\text{The symbol for the ion is $\large \boxed{\textbf{Fe$^{\mathbf{2+}}$}}$}$

4 0

3 years ago

3. What is the name for the items in this group as a whole: protons,

Sidana [21]

Answer: C) Subatomic particles

Explanation: I just learned this in ap environmental science

7 0

3 years ago

Which statements are true?

schepotkina [342]

Explanation:

Evaporation is defined as a process in which liquid state of water is changing into vapor state.

So, we need to break the bonds of liquid substance in order to convert it into vapor state. And, energy is absorbed for breaking of bonds which means that evaporation is an endothermic process.

Hence, the statement evaporation of water is an exothermic process is false.

When a hydrocarbon reacts with oxygen and leads to the formation of carbon dioxide and water then this type of reaction is known as combustion reaction.

A combustion reaction will always release heat energy. Hence, combustion reaction is exothermic in nature.

When energy is transferred as heat from the surroundings to the system then it means energy is being absorbed by the system. And, absorption of heat is an endothermic process for which $\Delta H$ is positive.

Whereas when energy is transferred from system to the surrounding then it means energy is released by the system which is an exothermic process.

Hence, for an exothermic process value of $\Delta H$ is negative.

Thus, we can conclude that statements which are true are as follows.

A combustion reaction is exothermic.

When energy is transferred as heat from the system to the surroundings, $\Delta H$ is negative.

For an endothermic reaction Deta H is positive.

5 0

3 years ago