how many moles of hydrogen are present in a 30.42 ml sample at 25.58 degrees celsius and 764.5. torr? assume the hydrogen is dry.
Answers
There are approximately 0.000486 moles of hydrogen present in the sample.
To find the number of moles of hydrogen present in the sample, you need to use the ideal gas law equation, which is PV = nRT where P is the pressure of the gas (in atm), V is the volume of the gas (in L), n is the number of moles of gas, R is the ideal gas constant, and T is the temperature of the gas (in K). First, you need to convert the pressure from torr to atm. You can do this by dividing the pressure in torr by 760, since 1 atm is equal to 760 torr. In this case, the pressure in atm would be: P = 764.5 torr / 760 = 1.0059 atm Next, you need to convert the volume from ml to L. You can do this by dividing the volume in ml by 1000, since 1 L is equal to 1000 ml. In this case, the volume in L would be: V = 30.42 ml / 1000 = 0.03042 L Finally, you need to convert the temperature from degrees Celsius to Kelvin. You can do this by adding 273.15 to the temperature in Celsius. In this case, the temperature in K would be:T = 25.58 degrees Celsius + 273.15 = 298.73 K Now that you have all the necessary values, you can plug them into the ideal gas law equation to solve for the number of moles of hydrogen: n = (PV) / (RT) = (1.0059 atm * 0.03042 L) / (8.31 J/mol*K * 298.73 K) = 4.86 x 10^-4 mol Therefore, there are approximately 0.000486 moles of hydrogen present in the sample
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Related Questions
BECAUSE i can't answer it
Answers
The concentration of urea in weight-percent 6.50%, in mole fraction is 0.0206 and in the concentration of urea in the solution in molarity is 1.12 M.
What is the concentration of Urea?a) To express the concentration of urea in weight-percent:
First, we need to calculate the total mass of the solution:
Total mass = mass of solute + mass of solvent = 66.0 g + 950 g = 1016.0 g
Then, we can calculate the weight-percent concentration of urea:
Weight-percent = (mass of solute/total mass) x 100%
Weight-percent = (66.0 g/1016.0 g) x 100%
Weight-percent = 6.50%
Therefore, the concentration of urea in the solution in weight-percent is 6.50%.
b) To express the concentration of urea in mole fraction:
First, we need to calculate the number of moles of urea:
Number of moles = mass of solute/molar mass of urea
Molar mass of urea = 2(14.01 g/mol) + 1(12.01 g/mol) + 1(16.00 g/mol) = 60.06 g/mol
Number of moles = 66.0 g/60.06 g/mol = 1.099 mol
Then, we can calculate the mole fraction of urea:
Mole fraction = moles of solute/(moles of solute + moles of solvent)
Moles of solvent = mass of solvent/molar mass of water = 950 g/18.02 g/mol = 52.71 mol
Mole fraction = 1.099/(1.099 + 52.71) = 0.0206
Therefore, the concentration of urea in the solution in mole fraction is 0.0206.
c) To express the concentration of urea in molarity:
Molarity = moles of solute/volume of solution in liters
Volume of solution = mass of solute + mass of solvent/density of solution = (66.0 g + 950 g)/1.018 g/mL = 978.4 mL = 0.9784 L
Molarity = 1.099 mol/0.9784 L = 1.12 M
Therefore, the concentration of urea in the solution in molarity is 1.12 M.
Exercise:
To compare the concentrations of 0.50 M NaCl and 0.25 M SrCl2 in µg/mL, we need to calculate the number of micrograms of each salt per milliliter of solution:
For 0.50 M NaCl:
Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol
Concentration in µg/mL = 0.50 mol/L x 58.44 g/mol x 1000 µg/mg = 29,220 µg/mL
For 0.25 M SrCl2:
Molar mass of SrCl2 = 87.62 g/mol + 2(35.45 g/mol) = 198.52 g/mol
Concentration in µg/mL = 0.25 mol/L x 198.52 g/mol x 1000 µg/mg = 49,630 µg/mL
Therefore, the concentration of 0.25 M SrCl2 is larger than the concentration of 0.50 M NaCl when expressed in µg/mL.
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Which is incorrect? multiple choice at equilibrium, ecell = 0. e > 0 for a spontaneous process. e = 0 for a spontaneous process. δg < 0 for a spontaneous process. δg = 0 at equilibrium.
Answers
The incorrect statement is e = 0 for a spontaneous reaction.
e cell = 0The cell potential is 0 at equilibrium.
e > 0 for a spontaneous reactionFor a spontaneous reaction the value cell potential E cell is positive i.e. >0
e = 0 for a spontaneous reactionThis statement is incorrect because the potential of a cell is positive if the reaction is spontaneous. Hence it cannot be zero.
δ g < 0 for a spontaneous reactionFor a spontaneous reaction gibbs free energy δ g value is negative i.e. < 0
δg = 0 at equilibrium.At equilibrium the value of gibbs free energy is zero i.e. δg = 0
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A current of 13.0 A is passed through molten magnesium chloride for 16.0 h. How many moles of magnesium metal could be produced via this electrolysis
Answers
Answer:
Moles of magnesium produced via this electrolysis is 3.8798 moles.
Explanation:
we know that the relation between current and charge is given by
I=Q/t
where
I=Current consumed
Q=amount of charge produced
t=time
Given,
amount of current passed (I)=13A
Total time (t)= 16 h
moles of magnesium=?
we know the electrolysis equation of magnesium chloride'
Mg+2 + 2e- -------> Mg
which says that, 2 coloumbs of charge required to produce 1 mole of magnesium.
we can caluclate the charge produced from the given data using the relation I=Q/t
13A=Q/16*60*60
Q=748,800 coloumbs
=748,800/96500 F (1F=96500C)
Q=7.76 F
from the electrolysis equation, 2F charge produces 1 mole of magnesium.Similarly,
moles of magnesium produced by 7.76F charge =7.76/2=3.387 moles
Which chemical formula shows a covalent compound?
NaCl
HBr
MgO
CO2
Answers
Answer:
CO2
Explanation:
A covalent compound is a compound between 2 nonmetals. For this reason, NaCl and MgO can be eliminated since both contain metals. While neither H nor Br are metals, in HBr H is acting as a metal. CO2 is the only choice containing both nonmetals, with both elements acting like nonmetals as well.
The pH of a solution is 8. Some hydrochloric acid is added to the solution. Suggest the pH of the solution after mixing. pH=.......??
Answers
Answer:
Probably around 6 because the ph of hydrochloric acid is 3
Explanation:
Balance and classify this reaction:
C6H6 +02 →CO2 +H₂O
Answers
2C6H6 + 9O2➡️ 6CO2 + 6H2O
Convert 160g to mg.
Answers
Answer:
160 grams is equal to 160,000 milligrams.
Explanation:
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Hope it helps!
Answer:
1g=1000mg
160g=160000
Fluorine belongs to group 17. How many covalent bonds are formed between two fluorine atoms?
Your answer:
1
2
3
4
Answers
Answer:
3??
Explanation:
hey??????????????
Fluorine is in group 7, meaning that it has 7 valence shell electrons and to fulfill the octet rule it can only obtain 1 more electron.
When bonding the last lone pair for each of the two fluorine atoms together you create a total of two electrons shared between each.
Therefore you get a total of 8 valence shell electrons.
Remember: when you have 8 valence shell electrons you have obtained an octet
In other words...
8 valence shell electrons = satisfied octet rule
A student is pouring baking soda in a beaker of vinegar at room temperature (23 °C). A chemical reaction occurs between the vinegar and baking soda. Which of the following conditions would result in the fastest reaction?
A) Pour 10g of baking soda into 250ml of vinegar at 33 °C.
B) Pour 10g of baking soda into 250ml of vinegar at 23 °C.
C) Pour 20g of baking soda into 500ml of vinegar at 13 °C.
D) Pour 20g of baking soda into 500ml of vinegar at 23 °C.
Answers
The conditions that would most likely produce the quickest reaction would be as follows:
C). Pour 20g of baking soda into 500ml of vinegar at 13 °C.
The condition that is most likely to generate the reaction at the fastest rate would include 20g(baking soda) along with 1/2 liter of Vinegar at the temperature of 13°C.The reason behind this is that the reaction that takes place between baking soda and vinegar exemplifies an endothermic reaction that produces CO2. The higher temperature produces a quicker reaction time and an adequate ratio of sodium bicarbonate and vinegar, the reaction takes place quickly and effectively.Thus, option C is the correct answer.
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Add a spoonful of sugar to one
cup of water. Add a spoonful of
oil to a second cup of water. Stir
each cup. Record your
observations below.
Answers
Answer:
The sugar will dissolve in water.
The oil will float in water.
Explanation:
The sugar molecules will fill up the remaining space between the molecules of water.
The oil being lighter and less denser than water floats in the water.
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What of these should Hailey include in her list?
Synthetic polymers are biodegradable.
Synthetic polymers are not flexible.
Synthetic polymers are recycled cheaply.
Synthetic polymers are inexpensive to produce.
Answers
Answer:
Hailey should add, they are inexpensive to produce.
Explanation:
Reason being why they are inexpensive to produce, is due to them being chemical based and easy to product in the factory setting. Which makes them extremely cheap to make.
Reason being why the others are wrong, synthetic polymers are not biodegradable as they are made in a factory with oils. Synthetic polymers are not flexible due to them being used for harder products. Synthetic polymers are not recycled cheaply as they are made with chemicals which makes it very hard to recycle.
answer:D
Explanation: i took it
A study was conducted of 90 adult male patients following a new treatment for congestive heart failure. One of the variables measured on the patients was the increase in exercise capacity (in minutes) over a 4-week treatment period. The previous treatment regime had produced an average increase of μ=2 minutes. The researchers wanted to evaluate whether the new treatment had increased the value of μ in comparison to the previous treatment. The data yielded y(bar)=2.17 and s=1.05.
(a) if the actual value of mu is 2.1 and alpha is reduced from 0.05 to 0.01, what would be the effect on the power curve?
(b) If the sample size is reduced from 90 to 50, what would be the effect on the power curve?
Answers
a. Decreasing alpha from 0.05 to 0.01 makes the significance level more stringent. You will be less likely to reject the null hypothesis, even when it's false. This increases the probability of a Type II error, thus potentially reducing the power of the test. The power curve will shift to the left.
b. If the sample size is reduced from 90 to 50, the effect on the power curve is that it will also shift towards the left.
What more should you know about decreasing the alpha and the power curve?The power curve is a graph that shows the probability of rejecting the null hypothesis as a function of the true value of the mean.
In the given scenarios of this study, Reducing the significance level and reducing the sample size will shift the power curve to the left, indicating a decrease in the statistical power of the test.
The power of a statistical test is the probability that it correctly rejects the null hypothesis when the alternative hypothesis is true.
a) Reducing alpha from 0.05 to 0.01 means that we are more stringent in our assessment of whether the new treatment is effective.
This will result in a decrease in the power of the test, meaning that it is less likely that we will be able to detect a difference between the new treatment and the previous treatment.
b) If the sample size is reduced from 90 to 50, the effect on the power curve is that it will also shift towards the left.
This is because a smaller sample size decreases the power of the test. A larger sample size provides more information and thus makes it more likely to correctly reject the null hypothesis when the alternative hypothesis is true.
Therefore, by reducing the sample size, you are decreasing the likelihood of detecting a true effect if one exists, thus reducing the power of the test.
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What is the specific heat capacity of silver metal if 110.00 g of the metal
absorbs 396 J of heat and the temperature rises 15.0°C ?
Answers
Answer:
"0.24 J/g.k" is the appropriate solution.
Explanation:
Mass of substance,
m = 110.00 g
Heat,
q = 396 J
Change in temperature,
ΔT = 15.0°C
Now,
The specific heat will be:
⇒ \(q=ms \Delta T\)
On putting the given values, we get
⇒ \(396=110.00\times s\times 15.0\)
⇒ \(396=s\times 1650\)
⇒ \(s=\frac{396}{1650}\)
⇒ \(=0.24 \ J/g.k\)
I'll give brainliest
Answers
Answer:
Number one is f 2 is c number 3 is c
Explanation:
Those are the answers
Answer:xmnjjnnnnnnnnnnnnnnnnnnnnnnxxxxxxxxxxxxxxxxxxxxxhn cfghjnbvghjmnbvghmkjhbnmjhb mjhgvbnmkjyokonownndjnxjnjdndlnjbkxnlknsjcnldx bExplanation:
What are the criteria of high-quality scientific research?
Provide at least three examples and explain them in detail.
Answers
High-quality scientific research is characterized by several key criteria. Three examples of such criteria include: rigorous experimental design and methodology, reliable data analysis and interpretation, and clear and transparent reporting of results.
These criteria ensure that research is conducted in a systematic and reliable manner, leading to trustworthy and valid findings.
Rigorous Experimental Design and Methodology: High-quality scientific research requires a well-designed experimental approach. This involves careful planning, proper control groups, randomization, and replication. A rigorous methodology ensures that experiments are conducted under controlled conditions, minimizing bias and confounding variables, and allowing for accurate and reliable data collection.
Reliable Data Analysis and Interpretation: After data collection, high-quality research involves thorough and appropriate analysis of the data. This includes using appropriate statistical methods to evaluate the significance of the results and drawing valid conclusions. Proper data analysis helps researchers identify patterns, trends, and relationships, supporting or refuting their hypotheses in an objective and reliable manner.
Clear and Transparent Reporting of Results: High-quality research demands transparent reporting of the methods, procedures, and findings. This includes providing detailed descriptions of the experimental setup, data collection processes, and statistical analyses used. Clear reporting allows other researchers to replicate the study and verify its results. Additionally, complete reporting ensures that readers can understand the research methodology and draw their own conclusions based on the evidence presented.
By adhering to these criteria, high-quality scientific research maintains integrity, credibility, and reproducibility. It fosters trust among the scientific community and facilitates the advancement of knowledge by building upon reliable foundations.
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Alcohols are flammable, suggest how the mixture of alcohols should be safely heated so that ethanol can be collected
Answers
How can the direction that the Moon rotates and revolves be described?
A. Diagonally
B. Horizontally
C. Clockwise
D. Counterclockwise
Answers
Answer: Counter-Clockwise.
Explanation: Please brainliest. I'm almost next tier.
How many grams of NH4ClO4 would dissolve in 250 mL at 30 C
Answers
True or false 1. A scientific model is representation of a particular phenomena
using something to make it easier to understand.
Answers
Answer:
True
Explanation:
The given statement is true.
A scientific model is defined as the mathematical and physical representation of a process or event. Scientists perform several observations or experiment and find a connection between them to prove a scientific finding.
A scientific model has the ability of explanatory power which helps to make things easier to understand using diagrams and consistency across contexts. Testing and prediction power in scientific models leads to strong predictions and able to convince people using an appropriate model.
Hence, the correct answer is "true".
QUESTION 8
DOK 4
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Imagine that an atom of Fluorine (F) can bond with one
of the following atoms. Which one do you think it is
most likely to bond with? Why?
Lithium (Li)
Beryllium (Be)
Boron (B)
Carbon (C)
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13:22 / 16:52
СС
Answers
Answer:
Li
Explanation:
F is a strongest electronegative element and it will combine with an element with low electronegativity. From the list provided, the element is Li.
some nitrogen atoms have seven neutrons and some have eight neutrons; these two forms of nitrogen are some nitrogen atoms have seven neutrons and some have eight neutrons; these two forms of nitrogen are ions of each other. phases of each other. isotopes of each other.
Answers
Certain nitrogen atoms contain seven neutrons, whereas others contain eight. Such two varieties of nitrogen have the same isotopes.
The only element that may contain seven protons was nitrogen, having the atomic number 7. Each isotope of nitrogen was represented by the given arrangement. This atom, which has eight neutrons, corresponds to nitrogen-15.
Isotopes have atoms with the same amount of protons but differing numbers of neutrons. They varies in mass, which affects their physical characteristics even when they have nearly identical chemical properties.
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Which of the following is the most stable isotope?
Isotopes AQ4
A. Polonium-210
B. Uranium-237
C. Francium-227
D. Plutonium-238
Answers
The most stable isotope among the the isotopic substance given from above is Plutonium-238.
The correct answer choice is option d.
How is Plutonium-238 the most stable isotope?Isotopy is the existence of a chemical element which result to having the same atomic number but different mass number.
From the given task above, the only isotope which is most stable is the Plutonium-238. This is because this isotope has a half life of alot of years; specifically; about 82,000,000 years.
Another interesting thing of factor which makes Plutonium-238 the most state from above is that Plutonium-238 itself decays into uranium-240 through alpha radiation.
There are three different types of radiation in science, these are as follows:
Alpha decayBeta decayGamma decay.In conclusion, we can now deduced from the above solution that Plutonium-238 is the most stable isotope from above.
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what is a mixture of elements and compounds
Answers
The substance in the image above would be classified as a mixture of elements (option E).
What is a compound and mixture?A compound is a substance formed by chemical bonding of two or more elements in definite proportions by weight.
On the other hand, a mixture is made when two or more substances are combined, but they are not combined chemically.
According to this question, an image is shown with two different substances or elements as distinguished by coloration (white and purple). These elements are combined but not chemically bonded, hence, is a mixture.
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How many elements are present in the compound Na_2S_2O_3
Answers
Answer:
3 elements are present in thr compound
A sample of hydrogen (H2) gas at 123 ∘C and has a pressure of 2.90 atm .At what final temperature, in degrees Celsius, will the pressure of the H2 decrease to 0.18 atm , if volume and amount of gas do not change?Express your answer using three significant figures.
Answers
In this question, we have a situation where a change in temperature and pressure occurs while the volume is kept constant, and in this situation, we have to use the Gay-Lussac's gas law formula to solve it, the formula is:
P1/T1 = P2/T2
Where:
P1 = initial pressure, 2.90 atm
T1 = initial Temperature in Kelvin, 123°C or 396 Kelvin
P2 = Final pressure, 0.18 atm
T2 = Final Temperature in Kelvin, ?
Now we add these values into the formula:
2.90/396 = 0.18/T2
0.0073 = 0.18/T2
T2 = 0.18/0.0073
T2 = 24.6 Kelvin of temperature, or -248 Celsius
What does this dialogue reveal about Paul’s feelings toward Ole Grey?
He has a deep fear of the horse, so he is cautious in his approach.
He is worried that the horse will not listen to him during the race.
He has a deep respect for the horse, so he treats him with care.
He is more concerned with winning than with the horse’s well-being.
Answers
Answer:
He has a deep respect for the horse,so he treats him with care
Answer:
It's C
Explanation:
Good luck on the test.
true or false the relevance of audit evidence or specific audit procedures depends on the assertion being tested
Answers
True, the relevance of Audit evidence and specific audit procedures depends on the assertion being tested. In an audit, assertions are representations made by management about the financial statements.
The auditor's role is to gather sufficient appropriate audit evidence to determine whether these assertions are reasonable and accurate. There are various assertions that auditors test, including:
1. Existence: Assets, liabilities, and equity interests exist at a specific date.
2. Rights and obligations: The entity holds rights to assets and is obligated for liabilities.
3. Completeness: All transactions and events are recorded in the financial statements.
4. Valuation and allocation: Assets, liabilities, and equity interests are recorded at appropriate amounts.
5. Presentation and disclosure: Components of the financial statements are appropriately presented and described.
To test each assertion, the auditor uses different types of audit evidence and procedures. For example, to test existence, the auditor may physically inspect assets or confirm balances with third parties. To test completeness, the auditor may perform analytical procedures to identify unusual trends or relationships.
The relevance of audit evidence refers to whether the evidence gathered pertains to the assertion being tested. Relevant evidence helps the auditor form a conclusion about the specific assertion. Similarly, specific audit procedures are tailored to address the risks associated with each assertion.
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The steady state vital to life is possible because:________
a. the cell cannot convert energy from one form to another.
b. all cells are autotrophic.
c. all reactions are exothermic.
d. the cell continually takes up energy from the environment.
e. all reactions are at equilibrium.
Answers
Answer: The correct answer is e) all reactions are at equilibrium.
Explanation: In order for cellular vitality to develop, it is necessary for it to be in energetic balance with the environment, that is, to give and receive energy with the environment that surrounds it through endothermic or exothermic reactions. That is why the development of life is considered a system that constantly exchanges with the environment. In turn, that the cell unit maintains a balance with the environment causes homeostasis to occur among the whole organism.
Using the periodic table, choose the more reactive nonmetal.
Br or As
Answers
Answer:
Br
Explanation:
what is the most common element found in the universe?
Answers
Answer:
Carbon, my good sir hope it helps!
Explanation: