Chemistry Middle School

10 Baking soda (NaHCO3) decomposes when it is heated according to the equation below. How many kilojoules of heat are required to decompose 1.95
mol
NaHCO3(s)?
2NaHCO3(s) + 1290 - Na2CO3(s) + H20(9) + CO2(9)
126 13
258
129 la
• 2.53 x 107

Answers

Answer 1

Answer:

253.02 kJ.

Explanation:

The balanced reaction for the decomposition of baking soda is

2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g)

We can find the heat of reaction by using the Hess' Law. This is done by using this formula:

∑(Hf,products) -∑(Hf,reactants) = Heat of reaction

where Hf is the heat of formation. According to literature, these are the heats of formation for each of the compounds in the reaction:

NaHCO3: -947.68 kJ/mol

Na2CO3: -1130.94 kJ/mol

CO2: -393.51 kJ/mol

H2O: -241.8 kJ/mol

Applying Hess' Law:

[1(-1130.94) + 1(-241.82)] + 1(-393.51)] - [2(-947.68)] = 129.09 kJ

Thus, the heat of reaction is 129.09 kJ/mol NaHCO3. Since there is 1.96 mol of NaHCO3, the total heat of reaction is 253.02 kJ.

Related Questions

how does the design of an experiment relate to the method of difference?

Answers

Answer:

The design of experiments (DOE, DOX, or experimental design) is the design of any task that aims to describe and explain the variation of information under conditions that are hypothesized to reflect the variation. The term is generally associated with experiments in which the design introduces conditions that directly affect the variation, but may also refer to the design of quasi-experiments, in which natural conditions that influence the variation are selected for observation.

Explanation:

Experimental design refers to how participants are allocated to the different groups in an experiment. Types of design include repeated measures, independent groups, and matched pairs designs.

Is the size of the country an important factor in how much helium that can be found there?

Answers

Brainless pls

Explanation:

Accordingly, any attempt to determine where the helium market will be more than a few years ... and/or recover helium can reduce the amount of helium consumed by as much as a factor ...

Answer:

Explanation:

Accordingly, any attempt to determine where the helium market will be more than a few years ... and/or recover helium can reduce the amount of helium consumed by as much as a factor..

Will give 100 points!

An earthquake has a high magnitude but a low intensity. Which statement best explains this?
A. Magnitude measures the energy released by the earthquake, while intensity measures the amount of damage.
B. Magnitude measures the duration of the earthquake, while intensity measures the amount of damage.
C. Magnitude measures the duration of the earthquake, while intensity measures the energy released by the earthquake.
D. Magnitude measures the energy released by the earthquake, while intensity measures its duration.

The National Seismic Hazard Map classified one location as having the “highest hazard” and another location as having the “lowest hazard.” Based on this classification, which conclusion can you draw between the "highest hazard" and "lowest hazard" locations?
A. "Highest hazard" locations are better prepared for an earthquake than the "lowest hazard" locations.
B. There will never be an earthquake in the "lowest hazard" location in the future.
C. There will definitely be an earthquake in the "highest hazard" location.
D. There is more likely to be an earthquake in a "highest hazard" location than in a "lowest hazard" location.

How are P waves different from S waves?
A. P waves move under Earth’s surface, and S waves move along Earth’s surface.
B. P waves cause damage, and S waves do not cause damage.
C. P waves travel slowly, and S waves travel quickly.
D. P waves push and pull in the same direction as the wave, and S waves move up and down.

What does a seismograph record?
A. the distance from the epicenter of an earthquake
B. the vibrations produced by an earthquake
C. the amount of damage that results from an earthquake
D. the total amount of energy released by an earthquake

Answers

1. Magnitude measures the energy released by the earthquake, while intensity measures its duration. The correct option is A.

2. The conclusion you can draw between the two conditions is that there is more likely to be an earthquake in a "highest hazard" location than in a "lowest hazard" location and is denoted as option A.

3. P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.

4. Seismographs are instruments used to record the motion of the ground during an earthquake. They are installed in the ground throughout the world and operated as part of a seismographic network.

Will give 100 points! An earthquake has a high magnitude but a low intensity. Which statement best explains

The Law of Conservation of Energy states...

A) energy cannot be created, but it can be destroyed and change forms
B) energy cannot be created, destroyed, or change forms
C) energy cannot be created or destroyed, but it can change forms
D) energy can be created, destroyed, and can change forms

Answers

Answer:

C) energy cannot be created or destroyed, but it can change forms

Explanation:

The correct answer is C. :)

You may think of changes in climate occurring as you go north or south. This climber stayed at the same latitude and went up. What explains the difference in temperature and climate between the top and bottom of Mt. Kilimanjaro? Please explain in 3-5 sentences thank you for 81 points

Answers

Answer: I'm not really sure but I think its dew to the different heights and tempura going up and down and the flow of wind.

Explanation:

Answer:

Mountains make it possible for snow to be found at the equator. Why does the temperature become colder the higher up a Mountain? Generally the climate on mountains get progressively colder with increased altitude (the higher up you go).

Explanation:

I WILL GIVE YOU BRAINLIST PLS DOOOOOO
Which of these is a characteristic of index fossils?

Found in the topmost rock layer

Found in many layers of the same rock

Have already established relative age

Are limited to a particular geographic location

Answers

Answer: It is the third one.

Explanation:

An index fossil is something that a human can estimate the age of the fossil by looking at it.

The answer is the third one.

Index fossils are distinct in nature and recognisable. It is also widely present across the world. It is abundant and found everywhere.

Water is one of the most important things to you, and to all living things. The fact that you can measure the volume of room temperature water with a beaker is a clue that room temperature water is in liquid form. If you keep raising the temperature of that water, it will eventually begin to boil, bubbling up and releasing steam. The steam is an example of what? *

Answers

Answer:

steam is and example of vapor and gas.

Answer:

evaporation

Explanation:

because the water boils and steam leave so it's evaporation

Using the data on the map, compare the chance of precipitation in Colorado to the
chance of precipitation in New York State. Include both states in your answer and
support your answer with scientific reasoning.

Answers

You didn’t include the data on the map :( post it in the comments please and I’ll help

?What statement best describes the arrangement of the atoms in an ethylene molecule?

Answers

Answer: Two electrons are shared between each hydrogen atom and the carbon atom bonded to it, and four electrons are shared between the carbon atoms.

Two electrons are shared between each hydrogen atom and the carbon atom bonded to it, and four electrons are shared between the carbon atoms.

How is interpreting a skeleton in an owl pellet similar to and
different from interpreting a fossil of a skeleton?

Answers

Answer:

Explanation: interpreting a skelton means stopping what its doing. While interpreting a fossil causes it to be taken out of its decaying form

In this OWL pellet dissection, BONES from a play provided information on the PREY that each OWL eat. Some of the BONES in the pellet were common to all THREE OWLS and some of the BONES where are unique to particular PREY. Identifying the unique PREY allowed us to determine which ENVIRONMENT each OWL was from.

EXPLANATION:

1st- BONES

2nd: PREY

3rd: ENVIRONMENT

Ps. Hope this helped!

:)

please help

I've finished all my other questions but I'm really stuck on these two

Answers

Answer: 66.66 / 66.67 / 66 2/3 hydrogen 33.33 / 33 1/3 oxogen

for question e

in grams of course

question e:66.66/66.67/66 2/3
hydrogen: 33.33/33 1/3 oxogen

Rank the nonmetals in each set from most reactive (1) to least reactive (3). Neon: Selenium: Fluorine:

Answers

selenium-1 flourine-2neon-3

Answer:

the top one is wrong its actually

Neon:

Selenium:

Fluorine:

Explanation:

What was the low temperature for hurricane Katrina?

Answers

Answer: 90 degrees F

Explanation:

The temperature was 90 F (32 C)

Why are cellular respiration and photosynthesis opposite processes?
This is in science for 7th grade

Answers

Answer:

photosynthesis removes carbon dioxide from the atmosphere while respiration puts back carbon dioxide.

Explanation:

hope this helps

photosynthesis is when she jabs so j she so ab and cellular respiration is also when you’d h.

Michelle is exploring the different kinds of changes that can happen to substances. She knows that changes can alter the looks or shape of a substance. Cutting, melting, bending, or crushing are examples of what kind of change?

A.product
B.physical
C.chemical

Answers

Answer:

Physical Change

Explanation:

Cutting, Melting and bending are examples of physical change because it changes the physical appearance of the object. and because you use physical strength to make all of these changes

The correct answer is B.

Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation: ()Na2HPO4 → ( )Na4P2O7 + ( )H2O

Answers

Answer:

The coefficients in order are 2, 1, 1

Explanation:

Each side of the reaction needs to have the same number of each element due to conservation of matter.

First I looked at what was uneven, notice there are 2 Na on the left side and 4 Na on the left. The easiest way to fix that is to add a 2 on the Na2HPO4:

2(Na2HPO4)--> Na4P2O7 + H2O

Next take count of each element on both sides to see if the 2 balanced everything:

On the left there are 4 Na, 2 H, 2 P, and 8 O

On the right there are 4 Na, 2 H, 2 P, and 8 O

Since both sides match, you are done!

How does an atom change if all of its electrons are removed?
p.s. I'll mark the first answer the brainliest if it is correct! ;)

a. The atom’s volume increases.

b. The atom’s mass increases.

c. The atom becomes positively charged.

d. The atom becomes negatively charged.

Answers

c. The atom becomes positively charged

if the electrons are removed it means theres no longer a negative charge to balance the positive charge of the protons in the atom

C the atom becomes positively charged

What is a characteristic of a fossil fuel? They do not cause pollution. They are formed quickly. They are renewable. They are found deep within the earth.

Answers

They are found deep within the earth. (Fossil fuels are the main cause of pollutions, they do not form quickly, and they are non-renewable resources.)

fossil fuels are found underground trapped under layers and layers of rocks

How to work out the relative mass of potassium? What is the calculation? ( explained very easily )

Answers

Answer:

Explanation:

Relative mass does not need to be calculated as it is listed on the periodic table. Potassium's relative atomic mass is around 39.

Relative Atomic Mass = Mass of one atom
———————————
(1/12)th Mass of one C12 atom

Please help me por favor :'(

Answers

More volume, takes longer to heat all the molecules.

Plants can only
cause mechanical weathering.
Please select the best answer from the choices provided
OT
OF

Answers

Answer:

Ice wedging, pressure release, plant root growth, and abrasion can all cause mechanical weathering. in the cracks and pores of rocks, the force of its expansion is strong enough to split the rocks apart. This process, which is called ice wedging, can break up huge boulders.

Answer:

Explanation:

When the speed of the bottle is 2 m/s, the KE is kg m2/s2. When the speed of the bottle is 3 m/s, the KE is kg m2/s2. When the speed of the bottle is 4 m/s, the KE is kg m2/s2. When the speed of the bottle is 5 m/s, the KE is kg m2/s2. When the speed of the bottle is 6 m/s, the KE is kg m2/s2.
instructions
In this part of the experiment, you will be changing the speed of the bottle by dropping it from different heights. You will use the same mass, 0.250 kg, for each trial, so record this mass in Table B for each velocity. Then, calculate the expected kinetic energy (KE) at each velocity. Use the formula KE = mv2,
where m is the mass and v is the speed. Record your calculations in Table B of your Student Guide.

Answers

Answer:

Based on the given instructions, you need to calculate the expected kinetic energy (KE) at each velocity using the formula KE = mv^2, where m is the mass and v is the speed. The mass is given as 0.250 kg.

Table B: Calculation of Kinetic Energy (KE)

Speed (m/s)Mass (kg)KE (kg m^2/s^2)20.2500.50030.2500.75040.2501.00050.2501.25060.2501.500

To calculate the kinetic energy at each velocity, multiply the mass (0.250 kg) by the square of the velocity.

For example, when the speed of the bottle is 2 m/s: KE = (0.250 kg) * (2 m/s)^2 = 0.250 kg * 4 m^2/s^2 = 1.000 kg m^2/s^2

Perform similar calculations for the other velocities and record the results in Table B.

Answer:

Explanation:mass of the bottle in each case is M = 0.250 kg

now as per given speeds we can use the formula of kinetic energy to find it

1) when speed is 2 m/s