Answer:
7.5 M
Explanation:
In order to find a solution's molar concentration, or molarity, you need to determine how many moles of solute, which in your case is sodium sulfate,
Na
2
SO
4
, you get in one liter of solution.
That is how molarity was defined -- the number of moles of solute in one liter of solution.
So, you know that you have
0.090
moles of solute in
12 mL
of solution. Your goal here will be to scale up this solution by using this information as a conversion factor to help you determine the number of moles of solute present in
A hypothesis is tested by ___.
A.) conducting an experiment
B.) making further observations
C.) proposing a theory
D.) talking with other scientists
A hypothesis is tested by conducting an experiment.
Answer: The correct answer would be A. Conducting Observation
Explanation:
Because....
If you don't conduct an experiment then how will you know if your hypothesis was true or not. So a hypothesis is tested by Conducting Observation.
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what was the period of time in london called because of the cold temp
Final answer:
The period of time in London known for cold temperatures is referred to as the Little Ice Age, which spanned from 1550 AD to 1850 AD, and included the Maunder Minimum with exceptionally low temperatures in Europe.
Explanation:
The period of time in London known for its cold temperatures was the Little Ice Age, which occurred between 1550 AD and 1850 AD. The Maunder Minimum, part of the Little Ice Age, was a time of exceptionally low temperatures in Europe, specifically during the seventeenth century. Europe experienced harsh winters with the River Thames freezing and low summer temperatures led to poor harvests. The impact of the Sun's activity on Earth's climate during this period remains a topic of debate among scientists.
The notable climatic anomalies during the Maunder Minimum underscore the intricate interplay between solar activity and Earth's climate, prompting ongoing scientific discourse and investigation into the complex mechanisms influencing historical temperature variations.
A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. How much potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years?
Answer:
[tex]\boxed{ \text{8.40 g}}[/tex]
Explanation:
The half-life of K-40 (1.3 billion years) is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction
half-lives t/yr Remaining
0 0 1
1 1.3 billion ½
2 2.6 ¼
3 3.9 ⅛
We see that after 2 half-lives, ¼ of the original mass remains.
Conversely, if two half-lives have passed, the original mass must have been four times the mass we have now.
Original mass = 4 × 2.10 g = [tex]\boxed{ \text{8.40 g}}[/tex]
Answer:
8.40 is correct
Explanation:
PLEASE HELP!!! Solid calcium combines with oxygen gas to form solid calcium oxide. Write a balanced equation and how many moles of calcium oxide would be produce if only 0.33 moles of oxygen were available?
Answer:
2Ca + O2 -> 2CaO
0.66 mol CaO
Explanation:
0.33 mol O2(2 mol CaO/1 mol O2) = 0.66 mol CaO
0.33 moles of oxygen would produce 0.33 moles of calcium oxide according to the balanced chemical equation for the reaction of solid calcium with oxygen gas. Additionally, calcium oxide is a very reactive substance with historical uses in lighting.
Explanation:The reaction of solid calcium (Ca) with oxygen gas (O2) to form solid calcium oxide (CaO) can be represented by the balanced chemical equation: 2Ca + O2 → 2CaO. This equation indicates that 1 mole of oxygen reacts with 2 moles of calcium to produce 2 moles of calcium oxide. If you have 0.33 moles of oxygen available, then using stoichiometric principles, you would also produce 0.33 moles of calcium oxide as the mole ratio of oxygen to calcium oxide is 1:1.
Calcium oxide, also known as quicklime or lime, is very reactive and emits an intense white light when heated to a high temperature. It's interesting to note that blocks of calcium oxide heated by gas flames were used as stage lights in theaters before electricity was available.
Furthermore, calcium hydroxide (Ca(OH)2) can be formed from the reaction of solid calcium oxide with liquid water. However, this step is not necessary to calculate the amount of calcium oxide produced in the original reaction.
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Consider the following reversible reaction
Answer:
The right choice is K(eq) = ([CO₂]) / [O₂]
Explanation:
The equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium
For a system undergoing a reversible reaction described by the general chemical equation
a A + b B → x X + n NAn equilibrium constant can be expressed as following
K(eq) = ([X]ˣ*[N]ⁿ) / ([A]ᵃ*[B]ᵇ)
where [] is the equilibrium concentration of each component.
and the concentration of solid is conventionally considered as 1
in your example:
The reversible reaction
C ₍s₎ + O₂ ₍g₎ ↔ CO₂ ₍g₎taking in consideration that C is a solid and the concentration of solid is conventionally considered as 1
So, the equilibrium constant for this reversible reaction can be expressed as following
K(eq) = ([CO₂]) / [O₂]∴ The right choice is K(eq) = ([CO₂]) / [O₂]
Final answer:
A reversible reaction involves reactants and products that can interconvert, and equilibrium is the state when their rates of formation are equal. The reaction quotient (Q) is used to assess the reaction's status.
Explanation:
A reversible reaction is a chemical process where the reactants form products, which can in turn react together to form the original reactants. This kind of reaction is denoted by a double-headed arrow. When a reversible reaction reaches a state where the rate of the forward reaction equals the rate of the reverse reaction, it is said to be at equilibrium. To evaluate the status of a reversible reaction, the reaction quotient (Q) is used, which compares the concentrations of the products and reactants at any given point in the reaction.
Reversible reactions are significant in many areas, including biochemical processes in the human body. Although some reactions may appear to proceed in one direction due to energetics or other factors, under the right conditions, reversibility is possible. The concept of equilibrium and the conditions affecting reversible reactions are fundamental to understanding chemical systems.
Which statements best describe the first stage of cellular respiration
Cellular respiration is the process of taking in glucose (sugar) and converting it into usable energy (ATP) so therefore the first stage would be taking the glucose into your bloodstream.
Answer:
The stage ha opens I in cytoplasm, glucose is broken down, and energy is released
Explanation:
I think
what is a general representation of a secondary amine?
Answer: general representation of a secondary amine is [tex]R_2NH[/tex] .
Explanation: Ammonia is [tex]NH_3[/tex] . When one or more H atoms of ammonia molecule are replaced by alkyl groups then the newly formed compounds are known as amines.
If one of the H atom from ammonia molecule is replaced by an alkyl group then we call it primary amine. It's written as [tex]RNH_2[/tex] .
If two H atoms of ammonia molecule are replaced by same or different alkyl groups then we call it secondary amine. It's written as [tex]R_2NH[/tex] and if all the three H atoms of ammonia molecule are replaced by same or different alkyl groups then we call it tertiary amine. It is written as [tex]R_3N[/tex] .
So, the general representation of a secondary amine is [tex]R_2NH[/tex] .
A general representation of a secondary amine is R₁-N(R₂)-R₃
Organic substituents R₁ R₂ , and R₃ are hydrogen atoms that are joined to the nitrogen atom (N).
Two organic substituents (R₁ and R₂), as well as one hydrogen atom (R₃), are attached to the central nitrogen (N).
A nitrogen atom is joined to two carbon atoms and one hydrogen atom to form the secondary amine family of chemical molecules. They are referred to as "secondary" amines because the nitrogen has two organic substituents (R₁ and R₂) bonded to them. While there is three organic substituents connected to the nitrogen in tertiary amines, there is only one organic substituent attached to the nitrogen in primary amines.
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What statement BEST describes weathering by a glacier?
A. constructive,involves gravity
B. constructive, builds up earth
C. destructive, wears down earth
D. destructive, moves sediment one place to another
Answer:
D
Explanation:
Because is other stuff can form from sediments then why can't glaciers
Need help !!!!! ASAP
The answer is:
We have that there were produced 0.120 moles of [tex]CO_{2}[/tex]
[tex]n=0.120mol[/tex]
Why?We are asked to calculate the number of moles of the given gas, also, we are given the volume, the temperature and the pressure of the gas, we can calculate the approximate volume using The Ideal Gas Law.
The Ideal Gas Law is based on Boyle's Law, Gay-Lussac's Law, Charles's Law, and Avogadro's Law, and it's described by the following equation:
[tex]PV=nRT[/tex]
Where,
P is the pressure of the gas.
V is the volume of the gas.
n is the number of moles of the gas.
T is the absolute temperature of the gas (Kelvin).
R is the ideal gas constant (to work with pressure in mmHg), which is equal to:
[tex]R=62.363\frac{mmHg.L}{mol.K}[/tex]
We must remember that the The Ideal Gas Law equation works with absolute temperatures (K), so, if we are given relative temperatures such as Celsius degrees or Fahrenheit degrees, we need to convert it to Kelvin before we proceed to work with the equation.
We can convert from Celsius degrees to Kelvin using the following formula:
[tex]Temperature(K)=Temperature(C\°) + 273K[/tex]
So, we are given the following information:
[tex]Pressure=760mmHg\\Volume=2.965L\\Temperature=25.5C\°=25.5+273K=298.5K[/tex]
Now, isolating the number of moles, and substituting the given information, we have:
[tex]PV=nRT[/tex]
[tex]n=\frac{PV}{RT}[/tex]
[tex]n=\frac{PV}{RT}[/tex]
[tex]n=\frac{760mmHg*2.965L}{62.363\frac{mmHg.L}{mol.K}*298.5K}[/tex]
[tex]n=\frac{760mmHg*2.965L}{62.363\frac{mmHg.L}{mol.K}*298.5K}\\\\n=\frac{2242mmHg.L}{18615.355\frac{mmHg.L}{mol.}}\\\\n=0.120mole[/tex]
Hence, we have that there were produced 0.120 moles of [tex]CO_{2}[/tex]
[tex]n=0.120mol[/tex]
Have a nice day!
A container of gas is initially at 0.500 atm and 25 degrees Celsius, what will be the pressure at 125 degrees Celsius?
0.688 would be the correct answer!
The table lists the half-life for four different isotopes of sulfur. Equal amounts of each sample are stored in sealed jars. Which Jar will contain the least amount of the isotope of sulfur after 10 seconds ?
Answer: A sulfur-30
Explanation: for Plato it’s right soo
After 10 seconds sulfur-30 would have decayed more because it has the least half-life.
What is Half life?
The half life of an element is the time taken for the element to decay to half of its original mass.
After 10 seconds;Sulfur-30 would have decayed by 10/1.18 s times. This will approximately 8.5 times.
Thus, after 10 seconds sulfur-30 would have decayed more because it has the least half-life.
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when baking soda and vinegar react, the product includes bubbles. what mostly likely occurred?
When baking soda, (a base) and vinegar (a acid) are mixed together, there is a chemical reaction, taking place, making the two diferent substances, one substance, that is now neutral.
A scientist is sitting in her living room and hears the wind rushing past her front door.
Based on her knowledge of Bernoulli's principle, what does the scientist know even without opening the door?
The air outside has less volume than the air inside.
There is less air pressure outside the door than inside the door.
The air outside has more mass than the air inside.
There is more air pressure outside the door than inside the door.
Answer:
Explanation:
Okay I just took this test and I will just tell you now
D is not the answer.
Sorry I couldn't be more help
Answer:
B
Explanation:
There is less air pressure outside the door than inside the door.
What is the atmospheric pressure when a liquid is boiling at its normal boiling point
Answer:
The boiling point of a liquid is the temperature at which its vapor pressure is equal to the pressure of the gas above it.The normal boiling point of a liquid is the temperature at which its vapor pressure is equal to one atmosphere 760 degrees
Explanation:
The atmospheric pressure when a liquid is boiling at its normal boiling point equals 1 atmosphere (atm) or 101.3 kilopascals (kPa). This is the point where the vapor pressure of the liquid matches the external atmospheric pressure.
Explanation:The atmospheric pressure when a liquid is boiling at its normal boiling point is known as 1 atmosphere (atm) or 101.3 kilopascals (kPa). The concept here revolves around the boiling point of a liquid, which is the temperature at which its equilibrium vapor pressure equals the external pressure exerted on the liquid by its gaseous surroundings. This is usually the Earth's atmospheric pressure in open containers.
Hence, when a liquid reaches its normal boiling point, the external atmospheric pressure equals 1 atm or 101.3 kPa. This means that at a liquid's normal boiling point, the vapor it produces has just enough energy to break free from the surface of the liquid without the help of further heating. For instance, the normal boiling point of water is 100 degrees Celsius, and this occurs at 1 atm of pressure.
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In Africa, as the crocodile lies with its mouth open, the plover, or crocodile bird, flies into its mouth and feeds on bits of meat stuck in the crocodile’s teeth. The crocodile does not harm the plover. The plover gets a meal and the crocodile gets his teeth cleaned. Describe the dynamics of this relationship.
A) It is a mutualistic relationship because both animals benefit; neither animal is harmed.
B) It is a symbiotic relationship because the plover benefits from the meat in the crocodile's teeth..
C) The crocodile is a predator. The plover is a parasite. There are two relationships illustrated by this dynamic.
D) It is an example of commensalism because the plover benefits from the relationship while the crocodile is neither helped or harmed.
NO!
Crocodiles do not eat Plovers. They only prey on larger birds like the Maribou Stork, or birds that are not quick enough to realize that they are being stalked.
So yes, A.
It is a mutualistic relationship because both animals benefit; neither animal is harmed. Therefore, the correct option is option A.
What is animal?Any of a group of multicellular eukaryotic creatures (Kingdom Animalia). It is assumed that they developed separately from unicellular eukaryotes. Animals vary fundamentally from participants in two major kingdoms of eukaryotic organisms, plants (Plantae) and fungus (Mycota), in form and physiology.
In Africa, as the crocodile lies with its mouth open, the plover, or crocodile bird, flies into its mouth and feeds on bits of meat stuck in the crocodile’s teeth. The crocodile does not harm the plover. The plover gets a meal and the crocodile gets his teeth cleaned. It is a mutualistic relationship because both animals benefit; neither animal is harmed.
Therefore, the correct option is option A.
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Identify the four parts of the potential energy diagram.
I think this is how to do it. but I'm sorry if it's not exactly right
Answer : The potential energy diagram is shown below.
Explanation :
Activation energy : The energy required to initiate the reaction is known as activation energy.
Or, it is the amount of energy required to reach the transition state.
Or, It is the minimum amount of energy that is absorbed by the reactant molecules so that their energy becomes equal to the threshold energy.
Or, the difference between the reactant and the transition state.
Enthalpy of a reaction : It is the energy change which takes place when the reactants go to the products. It is represented as, [tex]\Delta H[/tex]
Or, we can say that the difference between the product and the reactant.
If the heat is absorbed during the reaction then the enthalpy of reaction is positive and the reaction endothermic reaction.
If the heat is released during the reaction then the enthalpy of reaction is negative and the reaction exothermic reaction.
which group of extremophiles does thermus aquaticus belong to
Answer:
The correct answer is thermophiles.
Explanation:
Thermus aquaticus are heat resistant bacteria because these bacteria can survive under adverse environmental conditions like high temperature.
These bacteria belong to one of the most heat-loving groups of extremophiles that are thermophiles. Thermophiles are present in volcanic soil, geysers and around deep-sea vents where the temperature is extremely high.
Thermus aquaticus bacteria is used to manufacture an enzyme called Taq DNA polymerase, which is heat resistant and also an important factor in molecular biology.
Answer:
thermophiles is correct on edge
Explanatio
What type of reaction does this chemical equation represent
CH4 + 2O2 ➡️ CO2+2H2O+ energy
A. decomposition
B. Endothermic
C. Exothermic
D. Synthesis
Answer: exothermic
Explanation: It is a combustion reaction with methane.
The given chemical equation is representing the exothermic type of reaction. Therefore, option (C) is correct.
What is an exothermic process?An exothermic process can be demonstrated as a thermodynamic reaction that emits energy from the system to its surroundings, generally in the form of heat, light, or sound.
While an endothermic process is defined as an opposite of an exothermic process where the heat gets energy in the form of heat. The chemical bond energy in chemical reactions is transformed into thermal energy.
In exothermic reactions, the change in the kinetic energy of molecules when the heat is liberated. The electronic transition from one energy level to another causes light to be released.
The combustion reaction is the exothermic reaction therefore, the combustion of methane liberates heat along with carbon dioxide and water. When methane reacts with oxygen gas, it produces energy along with the other products of the combustion reaction.
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1. True or False? A Hertzsprung-Russell (H-R) diagram is a convenient way to see the relationship between the luminosity and the brightness of stars.
2. Convert the following temperatures.
A. B. C.
3. On an A.
B. C. D.
___ Kelvin = 100 oCelsius 0 Kelvin = ___ oCelsius 273 Kelvin =___ oCelsius
H-R diagram,
luminosity decreases from bottom to top.
temperature increases from left to right.
temperature decreases from left to right.
absolute magnitude increases from top to bottom.
4. What does a single dot on an H-R diagram represent? ________________________________ ________________________________
5. Which statement describes how a star moves within an H-R diagram?
A. A star never moves once its position is established on the diagram.
B. A star always stays in one region its entire existence.
C. A star migrates from one region to another as it goes through different stages.
D. All stars start in the upper left corner and travel through each region until they reach the bottom right corner.
6. On the H-R diagram above, identify the types of stars in the regions next to the lines 6A and 6B.
7. On the H-R diagram above, identify the general location of our Sun and label it.
8. How can you use the H-R diagram to find out if a giant star could have the same temperature as a red giant star? ________________________________ ________________________________ ________________________________ ________________________________
9. A star’s spectral class is most dependent on
A. its size and shape.
B. its color and temperature.
C. its luminosity and gravity.
D. its age and size.
10. The star Rigel in the constellation Orion has an absolute magnitude of 0.18 and is about 250 parsecs away. What is its apparent magnitude? Does it look brighter or dimmer than the star Vega to us? Vega’s apparent magnitude is 0.04. ________________________________ ________________________________ ________________________________ ________________________________ ________________________________
Help
Answer:
1 is true
I haven't read the rest!
A Hertzsprung-Russell (H-R) diagram is a convenient way to see the relationship between the luminosity and the brightness of stars. This statement is true.
What is A Hertzsprung-Russell (H-R) diagram ?The H-R diagram, also known as the HR diagram or HRD, is a scatter plot of stars that shows the relationship between the stars' absolute magnitudes or luminosities and their stellar classifications or effective temperatures.
373.15Kelvin = 100°Celsius, 0 Kelvin = -273.15°Celsius 273 Kelvin = -0.15°Celsius.
In the Hertzsprung-Russell (HR) Diagram, each star is corresponded by a dot.
All stars start in the upper left corner and travel through each region until they reach the bottom right corner.
The Sun is near the center of the main sequence, and stars spend the majority of their lives there.
The red-giant region is located in the upper right-hand corner of the H-R diagram, where these stars can be found (and Supergiant region). There are no red giants within 5 pc of the Sun, but many of the brightest stars in the sky are red giants.
A star’s spectral class is most dependent on its color and temperature.
A star's absolute magnitude, then when you compare it to calibration stars, you can find its distance. Its distance = 10(apparent magnitude - absolute magnitude + 5)/5.
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What is the molarity of a solution in which 10.0g of AgNO3 is dissolved in 500. mL of solution?
Answer:
[tex]\boxed{\text{0.118 mol/L}}[/tex]
Explanation:
[tex]\text{Molar concentration } = \dfrac{\text{moles}}{\text{litres}}\\\\\text{c} = \dfrac{n}{V}[/tex]
1. Convert grams to moles.
[tex]\text{Moles AgNO}_{3} = \text{10.0 g AgNO}_{3} \times \dfrac{\text{1 mol AgNO}_{3} }{\text{169.87g AgNO}_{3} } = \text{0.058 87 mol AgNO}_{3}[/tex]
2. Convert moles to litres
[tex]\text{V = 500. mL} \times \dfrac{\text{1 L}}{\text{1000 mL}} = \text{0.5000 L}[/tex]
3. Calculate the molar concentration
[tex]c = \dfrac{\text{0.058 87 mol}}{\text{0.5000 L}} = \text{0.118 mol/L}[/tex]
The molar concentration of AgNO₃ is [tex]\boxed{\textbf{0.118 mol/L}}[/tex].
The molarity of a solution in which 10.0g of AgNO₃ is dissolved in 500. mL of solution is 20M.
What is molarity?Molarity of any solution is define as the number of moles of solute present in per liter of solution.
M = n/V, where
n = moles of solute AgNO₃ = 10g
V = volume of solution = 500mL = 0.5L
On putting values on the above equation, we get
M = 10/0.5 = 20M
Hence required molarity of solution is 20 M.
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A 225 g sample of an unknown solid is heated 67C and placed into a calorimeter containing 25.6 g of water at 15.6°c. If the final temperature of the solid sample and the water is 53°C, what is the specific heat of the solid?
Answer:
= 1.271 J/g°C
Explanation:
Heat released by the metal sample will be equivalent to the heat absorbed by water.
But heat = mass × specific heat capacity × temperature change
Thus;
Heat released by the solid;
= 225 g × c ×(67 -53) , where c is the specific heat capacity of the metal
= 3150 c joules
Heat absorbed by water;
= 25.6 g × 4.18 J/g°C × (53-15.6)
= 4002.0992 joules
Therefore;
3150 c joules = 4002.0992 joules
c =4002.0992/3150
= 1.271 J/g°C
an object float or sink when placed on the surface of water science answer
im not quite understanding your question but, What you place in water depends on the mass of the object and its boincy. some rocks have so much air in them they can actually float but usally all rocks sink to the bottem. Thinks like plastics, styrofoams and paper can usally float on the surface of the water.
Calculate the mass of ammonium sulfide (NH4)2S in 3.00 L of a 0.020 M solution.
Answer:
4.09
Explanation:
Answer:
4.09
Explanation:
Consider the following equilibrium reaction having gaseous reactants and products.
4HCl + O2 ⇌ 2H2O + Cl2
Which of the following would result from increasing the volume of water vapors?
The volume of hydrochloric acid increases.
The rate of backward reaction decreases.
The rate of forward reaction increases.
The volume of chlorine increases.
Answer:
The volume of hydrochloric acid increases.
Explanation:
Le Châtelier's principle states that when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.Increasing the volume of water vapors:will increase the the concentration of the products side, so the reaction will be shifted to the left side (backward) to suppress the increase in the concentration of water vapors by addition.
So, The volume of hydrochloric acid increases, the rate of backward reaction increases, the rate of forward reaction decreases, and the volume of chlorine decreases.
So, the right choice is: The volume of hydrochloric acid increases.
What's responsible for eutrophication in seawater
Answer:
Some of the causes of eutrophication of seawater are: high concentrations of inorganic matter, sudden changes in temperature, changes in the pH of water and the ability of some organisms to adapt to adverse conditions.
Explanation:
Eutrophication is the process through which lakes, streams, or bays become overloaded with nutrient-rich water. When this occurs, large blooms of algae are produced and when the algae die, microorganisms in the water feed on the remains and consequently use up the available oxygen in the water. This leaves little oxygen for fish and other aquatic animals, resulting in the suffocation of aquatic life. Some of the responsables are:
Presence of higher concentrations of dissolved inorganics: nitrates, phosphates and silicates and carbon. A rise in temperature, dearth of dissolved oxygen, rapid fluctuation in pH-resulting in the absence of higher trophic level consumers.Ability of certain species under some genera to withstand or adapt to adverse conditions and resultantly out-competing other in terms of dominance.Eutrophication in seawater is primarily caused by excessive nutrient inputs, particularly nitrogen and phosphorus compounds, from human activities.
The eutrophication in seawaterThese nutrients can come from various sources such as agricultural runoff, sewage discharge, industrial waste, and atmospheric deposition. Here's a breakdown of the main factors contributing to eutrophication in seawater:
Agricultural Runoff: Fertilizers containing nitrogen and phosphorus are commonly used in agricultural practices. When it rains, these nutrients can be washed off the fields and enter nearby water bodies, including the ocean.
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which of the following symbols represents half-life?
The answer is B.) T /12
Answer: [tex]t_\frac{1}{2}[/tex]
Explanation:-
1. Activation energy is the extra energy required by the reactants to cross the energy barrier and convert to products. It is designated by the symbol [tex]E_a[/tex].
2. Half life is the time taken by a reactant to reduce to its original concentration. It is designated by the symbol [tex]t_\frac{1}{2}[/tex].
3. Alpha decay: In this process, alpha particles is emitted when a heavier nuclei decays into lighter nuclei. The alpha particle released has a charge of +2 units.
[tex]_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}+_2^4\alpha[/tex]
4. Beta-decay: In this process, a neutron gets converted into a proton and an electron releasing a beta-particle. The beta particle released carries a charge of -1 units.
[tex]_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+_{-1}^0\beta[/tex]
In the gas phase, a sample of molecules will have
Answer: the answer is a fixed shape
Explanation:
Hope this helps
In the gas phase, a sample of molecules will have low density.
According to the question;
We are required to identify what a sample of molecules will have in the gas phase.The gas phase of matter has some peculiar characteristics which include;
Ease of compressionThey expand to fill the entirety of their container volume.They occupy far more space than the liquids or solids from which they are form.As a consequence of the properties above; Although the mass of the molecules is constant, their volume increases drastically consequently rendering the density lower.
a
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To begin the experiment, 1.11g of methane CH4 is burned in a bomb
calorimeter containing 1000 grams of water. The initial temperature of water is 24.85oC. The specific heat of water is 4.184 J/g oC. The heat capacity of the calorimeter is 695 J/ oC . After the reaction the final temperature of the water is 35.65oC.
2. Calculate the change in temperature, ΔT
3. Using the formula qwater = m • c • ΔT ,calculate the heat absorbed by the water.
4. Using the formula qcal = Ccal • ΔT ,calculate the heat absorbed by the calorimeter.
5. The total heat absorbed by the water and the calorimeter can be calculated
by adding the heat calculated in steps 3 and 4. The amount of heat released
by the reaction is equal to the amount of heat absorbed with the negative
sign as this is an exothermic reaction. Using the formula ∆H = -(qcal qwater + ) ,
calculate the total heat of combustion.
6. Evaluate the information contained in this calculation and complete the
following sentence:
This calculation shows that burning ____________ grams of methane [takes
in/gives off] ______________ energy.
7. The molar mass of methane is 16.04 g/mol. Calculate the number of moles
of methane burned in the experiment.
8. What is the experimental molar heat of combustion?
9. The accepted value for the heat of combustion of methane is -890 KJ/mol.
Explain why the experimental data might differ from the theoretical value.
10.Give the formula theoretical value - experimental value % error = ×100
theoretical value , calculate
the percent error for the experiment
Answer:
2. ∆ T = 10.8 ˚C
3. q = 45,187.2 J
4. q = 7506 J
5. q (rxn) = - 52,693.2 J
6. This calculation shows that burning 1.11 grams of methane [takes in/gives off] gives off energy.
7. The number of moles of methane burned in the experiment = 0.069 mol.
8. Experimental molar heat of combustion = - 761,462.4 J/mol = - 761.5 kJ/mol
9. This may be attributed to experimental error occurring like thermometers misreading , heat loses to surrounding (as the efficiency of any calorimeter doesn't reach 100 % ), and poor lab technique.
10. % Error = 14.4 %
============================================
Explanation:
Firstly, from the given information
for water:
Initial temperature = T₁ = 24.85 °C
Final temperature = T₂ = 35.65 °C
So, the the change in temperature can be calculated
ΔT = Final temperature - Initial temperature
For calorimeter:
The heat capacity of the calorimeter is 695 J/ °C
============================================
2. ΔT = T₂ - T₁ = 35.65 °C - 24.85 °C = 10.80 °C
============================================
3. The heat absorbed by the water can be calculated from
q(water) = m • c • ΔT
where,
m =mass of water = 1000 g
C = The specific heat capacity of water = 4.184 J/g °C
So,
q(water) = m • c • ΔT = 1000 g * 4.184 J/g °C * 10.80 °C
q(water) = 45,187.2 J
============================================
4. To calculate the heat absorbed by the calorimeter,
one can use the formula
q(cal) = C(cal) • ΔT ,Where,
C = The heat capacity of Calorimeter = 695 J/ °C
So, Using the above formula
q(cal) = C(cal) • ΔT q(cal) = 695 J/ °C * 10.8 °C = 7,506 J.============================================
5. The total heat of combustion reaction can be calculated using the formula
∵ Amount of heat released by the reaction = - [Amount of heat absorbed by Calorimeter + Amount of heat absorbed by Water]
q (rxn) = -[q(cal) + q(water)
]
∴ q (rxn) = -[7,506 J + 45,187.2 J
] = - 52,693.2 J
That means that this is an exothermic reaction.
============================================
6. By evaluating the above information one can complete the following sentence:
This calculation shows that burning 1.11 grams of methane [takes in/gives off] gives off energy.
============================================
7. To calculate the number of moles of methane burned in the experiment
No. of moles = (mass / molar mass) = (1.11 g / 16.04 g/mol) = 0.069 mol
============================================
8. The experimental molar heat of combustion can be calculated from the following:
molar heat of combustion = (q (rxn) / no. ofmoles of methane)where q (rxn) is the total heat of combustion calculated in step 6, and no. of moles of methane was calculated in step 7.∴ Experimental molar heat of combustion = (q (rxn) / no. ofmoles of methane)
Experimental molar heat of combustion = (-52,693.2 J / 0.069 mol)
= - 761,462.4 J/mol
= - 761.5 kJ/mol.
============================================
9. The accepted value for the heat of combustion of methane is -890 KJ/mol. Explain why the experimental data might differ from the theoretical value.
This may be attributed to experimental error occurring like thermometers misreading , heat loses to surrounding (as the efficiency of any calorimeter doesn't reach 100 %),and poor lab technique.
============================================
10. Calculate the percent error for the experiment.
Given the formula below:
% Error = [Theoretical value - Experimental value) /Theoretical value] ×100
one can Calculate the percent error for the experiment
where
Theoretical value = - 890 KJ/mol.
Theoretical value = - 761.5 KJ/mol.
% Error = [Theoretical value - Experimental value) /Theoretical value] ×100
% Error = [(-890) - (-761.5) /(-890)] ×100
= 14.4 %
============================================
volume of carbon dioxide gas evolved at STP by heating 7.3 gram of Mg(Hco3)2 will be
Answer:
1.12dm³
Explanation:
The reaction is a decompositon reaction. It is expressed below:
Mg(HCO₃)₂ + Heat → MgCO₃ + H₂O + CO₂
This is the balanced reaction equation.
We have 1 mole of Mg, 2 mole of H, 2 mole of C, 6 mole of O on both sides of the reaction.
To calculate the volume of CO₂ gas evolved at S.T.P:
We work from the known to the unknown.
The known is Mg(HCO₃)₂ and the unknown is CO₂
1. Find the number of moles of Mg(HCO₃)₂ from the given mass
2. Since we know that chemical reactions obey the law of conservation of mass. The balanced chemical reaction shows that, 1 mole of Mg(HCO₃)₂ would give 1 mole of CO₂
3. We use information from (2) to find the number of moles of CO₂. With the number of moles of CO₂ found, we use the formula below to find the volume evolved at S.T.P
Volume evolved =
number of moles of CO₂ x 22.4dm³mol⁻¹
Solution:
Given/known parameters:
Mass of Mg(HCO₃)₂ = 7.3g
Step 1:
Number of moles
of Mg(HCO₃)₂ = mass/molar mass
Molar mass of Mg(HCO₃)₂ :
Atomic mass of Mg = 24gmol⁻¹
H = 1gmol⁻¹
C = 12gmol⁻¹
O = 16gmol⁻¹
Molar Mass Mg(HCO₃)₂
= [24 + 2{1 + 12 + (16 x3)} ]
= 24 + 2(1 +12 + 48)
= 24 + 122
= 146gmol⁻¹
Number of moles of
Mg(HCO₃)₂ = 7.3g/126gmol⁻¹ = 0.05mol
Step 2:
We know from the balanced equation that:
1mole of Mg(HCO₃)₂ = 1 mole of CO₂
So: 0.05mol of Mg(HCO₃)₂ = ?
This would also produce 0.05mol of CO₂
Step 3:
Volume of CO₂ evolved =
number of moles of CO₂ x 22.4dm³mol⁻¹
= 0.05 x 22.4
= 1.12dm³
The volume of CO₂ gas evolved at S. T. P is 1.12dm³
The volume of carbon dioxide gas evolved at STP by heating 7.3 gram of Mg(HCO3)2 will be 1.12 L or 1120 ml
Further Explanation: Molar gas volume Molar gas volume states that one mole of a gas occupies a volume of 24 liters when the gas is at room temperature and pressure (rtp), while one mole of a gas will occupy a volume of 22.4 liters at standard temperature and pressure (STP).Decomposition reactions These are reactions that involve break down of a compound to small molecules or atoms. Decomposition may be carried using heat (thermal decomposition) or using a catalyst (catalytic decomposition).An example;The reaction is a decomposition reaction;
Mg(HCO₃)₂ + Heat → MgCO₃ + H₂O + CO₂From the reaction
1 mole of Mg(HCO₃)₂ produces 1 mole of CO₂ after decomposition.
Therefore, to determine the volume of CO₂ produced by 7.3 grams of Mg(HCO₃)₂
Step 1: Moles of Mg(HCO₃)₂ in 7.3 gNumber of moles = Mass/relative formula mass
RFM of Mg(HCO₃)₂ =146.33868 g/mol
Therefor;
Number of moles = 7.3 g/146.33868 g/mol
= 0.04988
= 0.05 moles
Step 2: Moles of Carbon dioxide
From the equation;
1 mole of Mg(HCO₃)₂ produces 1 mole of CO₂ after decomposition.
Therefore;
Moles of carbon dioxide produced is 0.05 moles
Step 3: Volume of Carbon dioxide
From molar gas volume;
1 mole of CO₂ at STP occupies 22.4 L
Thus;
0.05 moles will occupy;
= 0.05 × 22.4 L
= 1.12 L or 1120 mL
Therefore; volume of carbon dioxide gas evolved at STP by heating 7.3 gram of Mg(Hco3)2 will be 1.12 L or 1120 ml
Keywords; Decomposition reactions, molar gas volume, relative formula mass, moles
Learn more about:
Relative Formula mass: https://brainly.com/question/5592681Moles calculation: https://brainly.com/question/5592681Molar mass: https://brainly.com/question/5592681Level: High school
Subject: Chemistry
Topic: Moles
Sub-topic: Molar gas volume
What is a chemical bond and why do atoms bond
Answer:
Explanation:
A chemical bond is a lasting attraction between atoms, ions molecules that enables the formation of chemical compound.