In H2O, the 2 is called a

Using standard heats of formation, calculate the standard enthalpy change for the following reaction. 2NH3(g) 3N2O(g)4N2(g) 3H2O

trasher [3.6K]

Answer: $\Delta H^{0} = -879.15 kJ/mol$

Explanation: Heats of formation is the amount of heat necessary to create 1 mol of a compound from its molecular constituents. The basic conditions the substance is formed is at standard conditions: 1 atm and 25°C. Each compound has its own heat of formation per mol of compound (kJ/mol), but to an element is assigned a value of zero.

Standard Enthalpy Change is defined as the heat absorbed or released when a reaction takes place. It can be positive or negative, which means reaction is endothermic or exothermic, respectively.

Enthalpy change is calculated as the difference between the sum of heat formation of products and the sum of heat formation of the reactants:

$\Delta H^{0}=\Sigma H^{0}_{f}_{(products)}-\Sigma H^{0}_{f}_{(reactants)}$

For the reaction

2NH₃ + 3N₂O → 4N₂ + 3H₂O

2(-46.2) + 3(82.05) 4(0) + 3(-241.8)

$\Delta H^{0}=3(-241.8)-[ 2(-46.2)+3(82.05)]$

$\Delta H^{0}=-725.4-153.75$

$\Delta H^{0}=-879.15$

The standard enthalpy change for the reaction is $\Delta H^{0}=-879.15$ kJ

8 0

2 years ago

Mention two factors which affect pressure due to liquid contained in a vessel

sveticcg [70]

Answer:

depth of the liquid and nature of liquid affects the pressure due to liquid contained in a vessel

3 0

2 years ago

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Match the following items. Match the items in the left column to the items in the right column. 1. general or nonspecific observ

ivann1987 [24]

when column B is like the attached pic: (missing in your question)

so the matches will be like that:

1- Qualitative :

as Qualitative is a general or nonspecific observation, they also don't require

measurements and even can't be measured, that is because of the reality is

being approximated only. It describes qualities and uses opinion

2- Hypothesis :

as a hypothesis is an educated guess quantitative, and it is a prediction stated

in " If and then " form. a hypothesis to be valid need a research such as:

-Encyclopedia & state and local research facilities & scientific journals.

3- Direct relationship:

as a Direct relationship is when two variable change in the same direction,

and one remaining larger than the other by the same factory.

- this is a type of a relationship in which there is a change with one variable, and corresponding with the change in the other. and because this corresponding change with the other variable in the same direction so it refers to a positive relationship.

4- Quantitative:

as Quantitative is a measured observation, It's an information or data based

on quantities obtained. And using numbers, equipment and standard units.

5- Control :

as control is standard, reference data or experiment qualitatively. this is what

you compare your experimental results to. This is for comparing results, it

used as a standard for comparison and use baseline measurements to use in

the comparing.

6- Theory :

as Theory is a presently accepted explanation of how something happened.

Scientifically acceptable general principles to explain phenomena. It the

general or abstract principles of the science. for example the wave theory of

light.

7- Law :

as a law is a statement that explains what something does under the same

conditions. when we take about law in science, it is a general rule to explain

the observations in the form of a mathematical statement. Scientific law may

be stated in words or expressed as a mathematical equations.

8- Best fit curve:

as best fit curve is a curve drawn to average the data's deviations direct

relationship. It is a process of constructing a curve that has best fit to a

series of data points.

7 0

3 years ago

Where does photosynthesis occur in a plant cell? In what part of a plant cell does photosynthesis occur?

Lynna [10]

Explanation:

In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll.

3 0

2 years ago

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Use the kinetic energy equation to explain why speed has a greater impact on kinetic energy than mass.

Lerok [7]

Answer: Hopefully this helps! sorry if not. :))

Speed has a greater impact on mass because its increases in velocity have an exponentially greater impact on translational kinetic energy because kinetic energy is proportional to velocity squared. Doubling an object's mass would only double its kinetic energy, however doubling its momentum would quadruple its velocity.

3 0

2 years ago