What does the A Hof a reaction represent?
A. It represents the heat involved in a reaction.
B. It represents the thermal energy in a system.
C.
represents the randomness of the products.
D. It represents the usable energy in a reaction.
egation.
Answer:
it represents the heat involved in a reaction
Explanation:
just took the test
The delta H of a reaction represents the heat involved in a chemical change .
What is a chemical change?
Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.
There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.
There are three types of chemical changes:
1) inorganic changes
2)organic changes
3) biochemical changes
During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.
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Chlorine and hydrogen gas react to form hydrogen chloride as shown in the following reaction: Cl 2 (g)+H 2 (g) 2HCl (g) If a 48.5 L sample of chlorine gas was reacted with excess hydrogen at 450 K and 1.20 atm , how many grams of hydrogen chloride is produced ?
It’s 1.58 moles
Answer:
H
Explanation:
Approximately 1229.80 grams of hydrogen chloride (HCl) is produced.
We must use the specified number of moles of the limiting reactant, in this case chlorine gas [tex](Cl_2)[/tex], to calculate the mass of hydrogen chloride (HCl) produced during the reaction. We can see from the balanced equation that 1 mole of [tex]Cl_2[/tex] results in the formation of 2 moles of HCl.
Given:
Volume of Cl2 gas = 48.5 L
Temperature (T) = 450 K
Pressure (P) = 1.20 atm
Moles of Cl2 = 1.58 moles
The ideal gas law equation can be used to calculate the amount of HCl produced:
PV = nRT
Where:
P = pressure
V = volume
n = moles
R = ideal gas constant
T = temperature
First, we must use the ideal gas law equation to obtain the amount of HCl in moles:
n(HCl) = (P * V) / (R * T)
Using the known values:
P = 1.20 atmV = 48.5 LR = 0.0821 L·atm/(K·mol)T = 450 Kn(HCl) = (1.20 atm * 48.5 L) / (0.0821 L·atm/(K·mol) * 450 K)
≈ 33.73 moles
To the nearest two decimal places, the mass of HCl is equal to its molar mass times its molar mass, or 33.73 mol times 36.46 g/mol, or 1229.80 g.
Mass of HCl = moles of HCl * molar mass of HCl
= 33.73 moles * 36.46 g/mol
≈ 1229.80 grams (rounded to two decimal places)
Therefore, approximately 1229.80 grams of hydrogen chloride (HCl) is produced.
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True or false: When adding acid to base the phenolphthalein indicator changes colour from colourless to pink at the end of the titration.
Answer: false
Explanation: I don’t know why but I just had this question and gussed false and I was right so false is therefore the right answer. Your welcome.
How is a calorimeter used in this experiment different from the ones used to find the energy content of a snack
Answer:
Kindly check the explanation section.
Explanation:
PS: Note that enough information are not being provided and we do not know the experiment this question is all about. However, some information are provided below which is going to aid in solving when you get access to the main question.
The determination of the heat transferred from one substance to another is one of the important aspect in science. The method in which this heat is being measured is known as calorimetry and the instrument used in this technique is known as the calorimeter.
When the energy content of a snack is needed to be calculated, there is the need use a type of instrument known as bomb calorimeter.
Most of the calorimeters used by students are not so expensive like the used in the industries. Most of these calorimeters operates at a constant pressure while the Bomb Calorimeter operates at constant volume.
What is the pH of an aqueous solution that has an H+ ion concentration of 0.10 M?
14
10
6
1
Answer:
1
Explanation:
pH = -log[H+] = -log(0.10) = log(1.0 x 10^-1) = 1
The pH scale determines how acidic or basic water is. The pH of an aqueous solution that has an H+ ion concentration of 0.10 M is 1. Therefore, option D is correct.
What is pH ?The pH scale, which previously stood for "potential of hydrogen," is used to describe how acidic or basic an aqueous solution is. The pH values of acidic solutions are typically lower than those of basic or alkaline solutions.
The range is 0 to 14, with 7 representing neutrality. Acidity is indicated by pH values below 7, whereas baseness is shown by pH values above 7. In reality, pH is a measurement of the proportion of free hydrogen and hydroxyl ions in water.
A solution's pH is a significant indicator of its chemical composition. The pH can affect how readily available nutrients are, how biological processes work, how bacteria behave, and how chemicals behave.
pH = -log [ H ⁺ ] = -log ( 0.10 )
= log ( 1.0 x 10⁻¹ )
= 1
Thus, The pH of an aqueous solution that has an H+ ion concentration of 0.10 M is 1. Therefore, option D is correct.
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what are the physical and chemical properties of acids? please specify which is which
what are the physical and chemical properties of bases?
Answer: Acids are chemical substances which are characterized by a sour taste in an aqueous medium. They have the tendency to turn blue litmus red. On the other hand, bases are chemical substances which are characterized by a bitter taste and are slippery to the touch. Some bases are soluble in water while others are not. Acids give off H+ (Hydrogen) ions in water; bases give off OH- (Hydroxide) ions in water. Acids generally taste sour due to the sour H+ ion; bases taste bitter due to the OH- ion; but they may have other tastes depending on the other part of the molecule. Bases are usually soapy in nature.
Explanation: Acids
Aqueous solutions of acids are electrolytes, meaning that they conduct electrical current. ...
Acids have a sour taste. ...
Acids change the color of certain acid-base indicates. ...
Acids react with active metals to yield hydrogen gas. ...
Acids react with bases to produce a salt compound and water.
Acids taste sour, conduct electricity when dissolved in water, and react with metals to produce hydrogen gas. Certain indicator compounds, such as litmus, can be used to detect acids. Acids turn blue litmus paper red. The strength of acids is measured on the pH scale.
Is Palladium an elementary substance or a compound?
Answer:
Elementary substance, since it is in the periodic table of elements.
Hope that helps!
-SCSB
Explanation:
PLS HELP ME!!!!!!!!!!!!!! I DON'T HAVE A LOT OF TIME !!!!!!!!
Answer: Well i think i have saw this i wolud say B hope this helps
Explanation:
how much atomic mass does Osmium have
Answer:
190.23g
Explanation:
Osmium is element number 76 on the periodic table, with the atomic symbol "Os." The atomic mass of any element is listed underneath the atomic symbol. Osmium has an atomic mass of 190.23 grams.
if life had existed during thie won the fossils probably would not have survived because
Answer:
because life would have use fossil for their benefits.
Can someone please help me with the right answer? I only have one more attempt :(
type of ions do acids give off? hydroniumm hydrogen heliumhy dronium and hydrogen
Answer:
Substances that give H + 1 ion when dissolved in water are called acids
Explanation:
The graphic represents the Milky Way galaxy.
Which label best represents the location of our solar system within the milky way galaxy?
A
B
C
D
Answer:
planets,meteoroids and asteroids
Explanation:
How do trends in the periodic table help predict the properties of an element
Describe the motion of the water molecules as the vapor pressure increases?
Answer: As for vapor pressure being higher at higher temperatures, when the temperature of a liquid is raised, the added energy in the liquid gives the molecules more energy and they have greater ability to escape the liquid phase and go into the gaseous phase.
Explanation:
The motion of the water molecules as the vapor pressure increases is:
The water molecules have greater energyAccording to the movement of the water molecules in a pressurized environment where the vapor and the temperature are increased, there is an increased ability to change from liquid to gas.
As a result of this, the water molecules has greater energy as they are subjected to increased levels of temperature and vapor pressure which makes them have more energy and to be more unstable.
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When the equation
Na +
H2O → __H, +
NaOH
is correctly balanced using the smallest whole-number coefficients, what is the coefficient for H2O?
The balanced equation is 2Na + 2H[tex]_2[/tex]O [tex]\rightarrow[/tex] 2NaOH + H[tex]_2[/tex] and the coefficient of H[tex]_2[/tex]O is 2. Stoichiometry represents the number of coefficients.
What is balanced equation?An equation for just a chemical reaction is said to be balanced if both the reactants as well as the products have the same number of atoms and total charge for each component of the reaction. In other words, each sides of both the reaction have an equal balance of mass and charge.
It is typical that balancing chemical formulas for both charge and mass in aqueous solutions. Equal numbers and types of atoms are produced on both aspects of the equation when balancing for mass. When the charge is balanced, there is no net charge on either side of the equation.
The balanced equation can be written as
2Na + 2H[tex]_2[/tex]O = 2NaOH + H[tex]_2[/tex]
The coefficient of H[tex]_2[/tex]O is 2.
Therefore, the balanced equation is 2Na + 2H[tex]_2[/tex]O [tex]\rightarrow[/tex] 2NaOH + H[tex]_2[/tex] and the coefficient of H[tex]_2[/tex]O is 2.
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what’s the process of natural selection
Answer:
Natural selection is the process through which populations of living organisms adapt and change. ... Through this process of natural selection, favorable traits are transmitted through generations. Natural selection can lead to speciation, where one species gives rise to a new and distinctly different species .
Explanation:
i just looked it up lol .
Mg + Cu2+ —> Mg2+ + Cu
a) why is this a redox reaction?
b) identify the oxidizing agent. Give reason for your answer
answer any of them you want please
Explanation:
Since the oxidation state of Mg is changed to +2 from 0, it is oxidized. (as it is increased)
Similarly, oxidation state of Cu is changed to 0 from +2, it is reduced. (as it is decreased)
Since oxidation & reduction occur at the same time, it is redox reaction.
As Mg is being oxidized, other one must be the oxidizing agent.
Cu is the oxidizing agent
Oleic acid's melting point is 14°C and it's boiling point is 360°С. What phase is this substance
at room temperature 25°C?*
A. Solid
B. Liquid
C. Gas
D. Impossible to tell
Extreme dryness is a characteristic of the____.
grasslands
desert
tropical rainforest
Answer:
desert
Explanation:
rainforest include a lot of rain, and grasslands have grass. grass includes water and sunlight. which leaves you to desert
what is the percent composition of potassium phosphate? show your work
Answer:
35.62%
Mass percent composition of K = 0.3562 x 100% Mass percent composition of K = 35.62%
Explanation:
A student investigates the speed of a ball rolling down a ramp. The student records their data in the table below. Which of these best explains the student’s data?
A. The speed of the ball increases as the ball rolls down the ramp because the force acting on the ball is greater than the force of gravity.
B. The speed of the ball increases as the ball rolls down the ramp because the forces acting on the ball are unbalanced.
C. The speed of the ball decreases as the ball rolls down the ramp because the forces acting on the ball are balanced.
D. The speed of the ball decreases as the ball rolls down the ramp because of friction between the ball and the ramp.
Answer:
b
Explanationbecause i took the test and got a 100
WILL GIVE BRAINLIEST
Answer:
b
Explanation:
More bushes of potatoes will be produced if the soil is fertilized more WHAT IS THE INDEPENDENT VAIRABLE AND THE DEPENDENT VARIABLE
Answer:
The dependent variable is the bushes of potatoes while the soil is an independent variable.
Explanation:
An experiment can be defined as an investigation which typically involves the process of manipulating an independent variable (the cause) in order to be able to determine or measure the dependent variable (the effect).
This ultimately implies that, an experiment can be used by scientists to show or demonstrate how a condition causes or gives rise to another i.e cause and effect, influence, behavior, etc in a sample.
Cause and effect can be defined as the relationship between two things or events in which an occurrence one (cause) leads to the occurrence of another (effect).
In an experiment , the variable being manipulated by an experimenter is known as an independent variable while the dependent variable is the event expected to change when the independent variable is manipulated.
Hence, the dependent variable is the bushes of potatoes while the soil is an independent variable.
How many mole are in 14.5 grams of neon please explain
Answer:
0.725 moles
Explanation:
Use the mole = mass/mr equation to find the moles.
Mole = 14.5/20 (Neon's Mr) = 0.725 Moles
Which equation is balanced?
A. H 2 + O 2 → H 2O
B. 2Na + Cl 2 → 2NaCl
C. KClO 3 → KCl 2 + 3O 2
D. CH 4 + 2O 2 → CO 2 + H 2 O
What gases are exchanged during respiration?
Answer:
Explanation:
there should be more showing than telling
Answer:
oxygen and carbon dioxide.
Explanation:
please help i genuinely don’t know what to do
How to calculate the number of moles
Answer:
1. The formula for the number of moles formula is expressed as.
2. Given.
3. Number of moles formula is.
4. Number of moles = Mass of substance / Mass of one mole.
5. Number of moles = 95 / 86.94.
please help people! science science! thank you!
Answer:
A. Is your answer
All the other ones are not valid because they are lower to the ground and you wouldn't have enough MOMENTUM to put you up for the top of the star.
Hope this helps!