Answer:
C. pH > pOH; Kw = 1.0 * 10^-14
Explanation:
The ion product of water, Kw = [H+]*[OH-] = 1.0 * 10^-14. It is a constant.
When an acid or base is added to water, its ion product does not change as it a constant. However, the relative concentrations of H+ ions and OH- ions will change depending on whether an acid or base is added to water.
When an acid is added to water, the concentration of H+ ions increases while that of OH- ions decreases, and vice versa.
Therefore, in the above situation where an acid is added to water, pH > pOH; Kw = 1.0 * 10^-14
the vessel in which electrolysis takes place is called
PLEASE GUYS ANSWER IT
Propenoic acid is an unsaturated carboxylic acid. Describe how you could show
that it is an unsaturated compound giving details of the test and the result.
Answer:
Tests for unsaturation involves addition across the multiple bonds in the unsaturated compound.
Explanation:
In organic chemistry, we define an unsaturated compound as any compound that contains a double or triple bond. These multiple bonds are also known as pi bonds.
There are two major tests for unsaturation which shall both be discussed here.
The first test for unsaturation is by the use of bromine water. The unknown sample is passed through a solution of bromine water which normally appears reddish brown. The bromine water becomes decolorized due to addition of bromine across the multiple bond. This is a standard test for unsaturation.
Secondly, unsaturated compounds decoulourize a solution of potassium permanganate when passed through it. This alone can not be used as a distinctive test for unsaturation.
Propenoic acid will give a positive test to the both reagents showing that it contains multiple bonds, in this particular instance, a double bond.
There are ___________ forces of attraction between particles in the gas state. Use the following word bank to help you.
Answer:
Different
Explanation:
What is the definition of acid ?
WILL MARK BRAINLIEST (if the answer is good and hasn't been copied from google and the first one who answer the question )
Answer:
Acid is a compound which dissolves in water to produce hydrogen ions (H+) and described as proton donors.
Reply ASAP: Why do electrons affect the structure of a molecule?
A. Bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.
B. They do not.
C. The electron clouds are negatively charged and repel each other as far apart as possible.
D. Bonding pairs are negatively charged and lone pairs are positively charged and they push each other into certain shapes.
Answer:
C. The electron clouds are negatively charged and repel each other as far apart as possible
Explanation:
This is the basis of VSEPR theory.
The angles between the electron clouds determine the shapes of the molecules.
B. and D. are wrong. All electron pairs are negatively charged.
The electrons affect the structure of a molecule because the bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.
What is the shape of an atom?Every atom or molecule consist some kind of geometry or shapes like linier, tetrahedral, square planner, octahedral etc. with some bond length and angles present with them.
The bond pairs in a geometry is made up with positive charge and lone pairs present on the atom in the form of negative charge as they both are opposite in nature and repel or push each other in opposite direction.
Due to this phenomena the structure of the atom gets effected and geometry will change on the basis of lone pair and bond pair repulsion.
Therefore, electrons affect the structure of a molecule because the bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.
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If a gas at 35°C and 2.3 atm is heated to 50°C, then what will the new pressure be? (Gay Lussac's Law)
Remember to convert Celsius tempertature into Kelvin. (Take the Celsius values and add 273)
Answer:
THE NEW PRESSURE OF THE GAS AT 50 °C IS 2.41 atm.
Explanation:
Initial temperature = 35 °C = 35 + 273 K= 308 K
Final temperature = 50 °C =50 + 273 K = 323 K
Initial pressure = 2.3 atm
Final pressure = unknown
Using the combined gas equation to get the relationship between pressure and temperature for a given gas sample, we have;
P1 / T1 = P2 / T2
P2 = P1 T2 / T1
P2 = 2.3 * 323 / 308
P2 = 742.9 /308
P2 = 2.41 atm.
THE NEW PRESSURE IS 2.41 atm at 50 °C
Inorganic compounds which are found in the earth are called: minerals vitamins synthetics cement
Answer:
Minerals
Explanation:
I looked it up on google. Thanks.
Which substances are products of a fermentation reaction?
1.water and carbon dioxide
2.alcohol and carbon dioxide
3.soap and glycerol
4.ester and water
Answer:
2.alcohol and carbon dioxide
Explanation:
Fermentation is a metabolic process which is used to produce chemical changes in various organic substances. This process is used in many fields including biochemistry, where it is defined as the "extraction of energy from carbohydrates in the absence of oxygen". The main substances produced from fermentation reaction are alcohol, carbon dioxide and lactic acid.
Convert to standard notation.
8.127 x
10-4
Answer:
0.0008127
Explanation:
This is easy
Consider the intermediate equations: 3 equations.
C(s) + O2(g) --> CO2(g) Delta H1 = -393.5 kJ
2CO(g) + O2(g) --> 2CO2(g) Delta H2 = -566.0 kJ
2H2O(g) --> 2H2(g) + O2(g) Delta H3 = 483.6 kJ
With the overall reaction:
C(s) + H2O(g) --> CO(g) + H2(g) Delta Hrxn = ?
QUESTION 1:
What must be done to calculate the enthalpy of reaction?
The first must be halved.
The first must be reversed.
The second must be halved.
The second must be reversed.
The third must be halved.
The third must be reversed.
QUESTION 2:
What is the overall enthalpy of reaction?
Delta Hrxn = ____ kJ
Answer:
C. The second equation must be halved
D. The second equation must be reversed
E. The third equation must be halved.
Delta Hrxn= 131.3 kJ
Explanation:
The correct answer is -582 KJ.
What is the enthalpy of reaction?
Enthalpy is the heat content of a system.The enthalpy change of a reaction is roughly equivalent to the amount of energy lost or gained during the reaction.A reaction is favored if the enthalpy of the system decreases over the reaction.What is the overall enthalpy of the reaction?
Equal to the sum of the standard enthalpies of the intermediate reaction steps is called overall enthalpyLearn more about enthalpy below,
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In the following reaction, which are the products?
Mg + 2HCl —> H2 + MgCl2
If you could, please explain as well.
Answer: H2 + MgCl2
Explanation: As they are on the right side of the equation/ are the products being made as a result of the reaction, they are the products.
Identify this molecule
Answer:
Ribose
Explanation:
This is the pentose sugar found in RNA commonly.
what is an example of a soultion
Answer:
Did you mean solution??
In chemistry, a solution is considered as a special type of homogeneous mixture composed of two or more substances. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent.
Eg: sweet tea or coffee (sugar added to solution)
bleach (sodium hypochlorite dissolved in water)
HOPE IT HELPS :)
1. If the potassium hydrogen phthalate is not completely dry, how would it affect the reported molar concentration (molarity) of the NaOH solution in Part A? Explain.
The given question is incomplete. The complete question is as follows.
Pure potassiom hydrogen phthalate is used for standardization of the sodium hydroxide solution. Suppose that the potassium hydrogen phthalate is not completely dry. Will the reported molar concentration of the sodium hydroxide solution be too high, too low, or unaffected because of the moistness of the potassium hydrogen phthalate? Explain please.
Explanation:
When potassium hydrogen phthalate is not completely dry then it means there will be some water present in it. According to this, actual potassium hydrogen phthalate is diluted because of the presence of water molecules.
Hence, 1 mole of potassium hydrogen phthalate needs 1 mole of NaOH. And, at the equivalence point according to the concept of moles:
No. of moles of potassium hydrogen phthalate = No. of moles of NaOH
Also, the titration of potassium hydrogen phthalate concentration is less because of the presence of water then the number of moles of NaOH calculated will be less.
Thus, we can conclude that the molar concentration of the sodium hydroxide solution be too low.
A 50.0 mL sample of 6.0 M HCl was diluted to a final volume of 250.0 mL What was the new molarity?
Answer:
1.2M
Explanation:
Initial Volume 0.05L
Final Volume 0.250L
HCl Molar mass: 36.46 g/mol
M = 6M HCl
Molarity = mol solute / L of solution
Inital M = Molarity = 6
mol solute = X = unknown
L of Solution = 0.05L
6 = X / 0.05
X = 0.3
X = 0.3/0.25
X = 1.2 M
8. A 65.0 mL 0.513 mol/l solution of glucose (C6H1206) was mixed with 125.0 mL of
2.33 mol/l glucose solution. What is the molar concentration of the final solution?
Assume the volumes are additive. The molar mass of glucose is 180 g/mol (10
points)
Answer:
The molar concentration of the final solution is 1.71 [tex]\frac{moles}{liter}[/tex]
Explanation:
Molarity is a way of expressing the concentration of solutions and indicates the number of moles of solute dissolved per liter of solution.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution.:
[tex]Molarity (M)=\frac{number of moles of solute}{volume}[/tex]
Molarity is expressed in units ([tex]\frac{moles}{liter}[/tex]).
Then, the number of moles of solute can be calculated as:
number of moles of solute= molarity* volume
So, in this case, the final concentration can be calculated as:
[tex]Final molarity (M)=\frac{Total number of moles of solute}{Total volume}[/tex]
where, being 65 mL=0.065 L, 125 mL=0.125 L and 190 mL=0.190 L (because 1000 mL= 1 L):
Total number of moles of solute= 0.065 L*0.513 [tex]\frac{moles}{liter}[/tex] + 0.125 L*2.33 [tex]\frac{moles}{liter}[/tex]= 0.033345 moles + 0.29125 moles= 0.324595 molesTotal volume= 65 mL + 125 mL= 190 mL= 0.190 LReplacing:
[tex]Final molarity (M)=\frac{0.324595 moles}{0.190 L}[/tex]
Final molarity ≅ 1.71 [tex]\frac{moles}{liter}[/tex]
The molar concentration of the final solution is 1.71 [tex]\frac{moles}{liter}[/tex]
An invasive fish species was accidentally introduced into a river. At first, it experienced a sudden surge in its population. Then it experienced a steady decline. Which statements give plausible reasons for this trend?
Answer:
Correct Option is Option A
A.)It became prey to certain organisms in the river.
Explanation:
CHECK COMPLETE QUESTION BELOW;
An invasive fish species was accidentally introduced into a river. At first, it experienced a sudden surge in its population. Then it experienced a steady decline. Which statements give plausible reasons for this trend?
A.It became prey to certain organisms in the river.
B.It lacked adaptations suitable for that particular ecosystem.
C.It had no predators in its new environment.
D.It had few organisms to compete with for resources.
Aquatic invasive species are species such as fish or invertebrate that is absorbed by new aquatic environment that are differ from their own natural environment.
When Aquatic invasive species found themselves in a new environment, at first they will experience a rapid increase in the number of their population this is because of the lack of natural predators in the new aquatic environment. As a result of this they bring about the alteration of food web structure, they take in charge of available food for the native species and compete with them. As a result of this competition involved there is a decrease in the population.
Therefore, the statements that gives plausible reasons for this trend is that became prey to certain organisms in the river.
Answer:
It became prey to certain organisms in the river.
It lacked adaptations suitable for that particular ecosystem.
Explanation:
Took the test on Edmentum
D
Which word equation shows hydrogen reacting with oxygen to form water?
anygen - water - hydrogen
hydrogen-orbeneater
appudaplu...dk
und---- udaplu
explanation
the chemical formula of water is H²O.
Hydrogen+Oxygen=water
answer
Hydrogen-Water-Hydrogen
nvironmental Science
a.
Identify the biotic factor of an ecosystem from the following:
soil composition
b. trees
temperature
d. sunlight
C.
Answer:
c
Explanation:
Soil, Plants get energy from the sun.. Answer is C.
Answer:
B. trees
Explanation:
A biotic factor is something in an environment or ecosystem that is living. For example, plants and animals are biotic factors. An abiotic factor is just the opposite-they are not living. Rocks and water are examples of abiotic factors.
Soil composition, temperature and sunlight are all not alive. Therefore, they must be abiotic factors.
Trees are living organism. This means that they are biotic factors. So, the correct answer is B: trees.
Which statement best compares the energy involved in melting with the energy involved in boiling for a given liquid?
Answer: Energy is removed from the particles in each change, but more energy is removed in melting than in boiling because the attractions are weaker. Energy is removed from the particles in each change, but more energy is removed in boiling than in melting because the attractions are weaker. Energy is added to the particles in each change, but boiling requires more energy than melting because the attractions must be completely overcome. Energy is added to the particles in each change, but melting requires more energy than boiling because the attractions must be completely overcome.
The sodium salt, NaA, of a weak acid is dissolved in water; no other substance is added. Which of these statements (to a close approximation) is true?
Answer:
Your question is somewhat poorly worded, even so what I can contribute is the statement is false, since the salt is sodium chloride, where its severe chemical formula NaCl, is a SALT not an acid and if it dissolves in water, seriously the solute of a solution, where water plays the role of the solvent
Explanation:
Sodium chloride is a binary salt, very easy to dissolve in water, it is also called the famous table salt, since it can be ingested in food even though it is not so recommended against high blood pressure conditions.
The United States consumes more oil per day than any other country. What would most likely happen to oil prices and availability worldwide if the United States were able to switch immediately to synfuels such as liquefied coal?
A. Oil prices would increase, and availability would increase. B. Oil prices would increase, and availability would decrease.
C. Oil prices would decrease, and availability would increase.
D. Oil prices would remain the same, and availability would increase.
E. Oil prices would remain the same, and availability would remain the same. PLEASE HURRY!!
Answer:
Oil prices would decrease, and availability would increase
Explanation:
A 2.575 g piece of gold (specific heat = 0.129 J/g°C) at a temperature of 75°C is placed into cold water at 10°C. If the gold loses 10.0 J of energy, what is its final
temperature in the water? Enter your answer to the
nearest whole number of °C.
Answer:
The final temperature of the mixture is 44.9°C
Explanation:
Mass of the substance (gold) = 2.575g
Specific heat capacity of gold = 0.129J/g°C
Initial temperature (T1) = 75°C
Final temperature (T2) = ?
Energy lost = 10J
Heat energy(Q) = MC∇T
Q = heat energy (in this case lost)
M = mass of the substance
C = specific heat capacity of the substance
∇T = change in temperature of the substance = (T2 - T1)
Q = MC∇T
Q = MC(T2 - T1)
-10 = 2.575 × 0.129 × (T2 - 75) energy is -ve because it was energy lost.
-10 = 0.3321 × (T2 - 75)
-10 = 0.3321T2 - 24.9075
Collect like terms
0.3321T2 = 24.9075 - 10
0.3321T2 = 14.9075
T2 = 14.9075 / 0.3321
T2 = 44.88
T2 = 44.9°C
The final temperature of the mixture is 44.9°C
If the pH of a solution is 9, the solution is A. acidic, which turns phenolphthalein pink B. acidic, which turns phenolphthalein colorless C. basic, which turns phenolphthalein pink D. basic, which turns phenolphthalein colorless
Answer:
C.
Explanation:
pH > 7, basic, so pH = 9 is basic.
When solution is basic, it will turn phenolphthalein pink.
A piece of lithium metal is added to a beaker that contains water and phenolphthalein. Using what you know about the properties of bases, choose the best explanation for what you observe.
Answer:
The phenolphthalein is turning pink because a base is forming.
Lulu Labwrecker carefully pipets 25.0 mL of 0.525 M NaOH into a test tube. She places the test tube into a small beaker to keep it from spilling and then pipets 75.0 mL of 0.355 M HCl into another test tube. When Lulu reaches to put this test tube of acid into the beaker along with test tube of base she accidentally knocks the test tubes together hard enough to break them and their respective contents combine in the bottom of the beaker. Is the solution formed from the contents of the two test tubes acidic or basic? What is the pH of the resulting solution?
Answer:
The solution formed is acidic
pH = 0.87
Explanation:
The acid-base reaction of NaOH with HCl is:
NaOH + HCl → NaCl + H₂O
Where 1 mole of NaOH reacts with 1 mole of HCl
In the problem, moles of NaOH and HCl are:
NaOH: 0.0250L × (0.525mol / L) = 0.013125 moles NaOH
HCl: 0.0750 × (0.355mol / L) = 0.026625 moles HCl
As moles of HCl > moles NaOH, HCl is in excess and the solution formed is acidic
Moles in excess of HCl are:
0.026625 moles - 0.013125 moles = 0.0135 moles HCl
As the volume of the solutions is 25.0mL + 75.0mL = 100.0mL = 0.100L, molarity of HCl after reaction is:
0.0135 moles HCl / 0.100L = 0.135M HCl = 0.135M H⁺
As pH is defined as - log [H⁺], pH of the solution is:
pH = -log 0.135M H⁺ = 0.87
pH = 0.87
The pH of the resulting solution of the acid and base mixture is; Acidic with a PH = 0.87
We are given;
Volume of NaOH = 25 mL = 0.025 L
Volume of HCl = 75 mL = 0.075 L
Concentration of NaOH = 0.525 M
Concentration of HCl = 0.355 M
Total volume of solution = 0.025 + 0.075 = 0.1 L
Now, the the equation of the reaction is;
HCl + NaOH = NaCl + H2O
We can see that 1 mole of HCl reacts with 1 mole of NaOH.
Since; number of moles = Volume × concentration
Number of moles of HCl = 0.075 × 0.355
Number of moles of HCl = 0.026625 moles
Similarly;
Number of moles of NaOH = 0.025 × 0.525
Number of moles of NaOH = 0.013125 moles
We can see that the number of moles of HCl is greater than that of NaOH and as such there is excess HCl acid in the mix.
Thus,
Excess moles of HCl acid = 0.026625 - 0.013125
Excess moles of HCl acid = 0.0135 moles
Concentration of this excess HCl is gotten by the formula;
M = Excess moles/total volume
M = 0.0135/0.1
M = 0.135 M
PH of this excess concentration is;
PH = -log [H+]
PH = -log [0.135]
PH = 0.87
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1. 7.85 g of sodium metal is added to 200 mL of 0.0450 M HNO3
a) Predict the mass of the precipitate
b) Predict the amount of excess reagent left over
c) Volume of gaseous product at STP conditions
Answer:
a)0.765 g
b)7.613 g
c)0.20 L
Explanation:
Consider the reaction involved;
Na(s) + HNO3(aq) ----> NaNO3(s) + H2(g)
Note that, if a hot, saturated aqueous solution of sodium nitrate was allowed to cool, solid sodium nitrate would crystallise out of the solution and this would also be classed as a precipitate. This is the case here.
Number of moles of sodium reacted= mass of sodium reacted/ molar mass of sodium
Number of moles of sodium= 7.85g/23gmol-1
Number of moles of sodium= 0.34 moles of sodium
Number of moles of acid reacted= concentration of acid × volume of acid
Number of moles of acid= 0.0450 × 200/1000
Number of moles of acid= 9×10^-3 moles
Therefore, HNO3 is the limiting reactant.
1 mole of HNO3 yield 1 mole of NaNO3
9×10^-3 moles of HNO3 yield 9×10^-3 moles of NaNO3
Hence mass of NaNO3= number of moles × molar mass
Mass of NaNO3= 9.0×10^-3 moles × 84.9947 g/mol
Mass of NaNO3= 0.765 g of NaNO3
b)
Since
1 mole of sodium metal reacts with 1 mole of HNO3
9×10^-3 moles of sodium reacts with 9×10^-3 moles of HNO3
Therefore amount of unreacted sodium metal = 0.34 moles - 9×10^-3 moles = 0.331 moles
Mass of unreacted sodium metal = 0.331 moles × 23 gmol-1= 7.613 g
c)
If 1 mole of HNO3 yields 1 mole of hydrogen gas
9×10^-3 moles of HNO3 yields 9×10^-3 moles of hydrogen gas.
1 mole of hydrogen gas occupies 22.4 L
9×10^-3 moles of hydrogen gas will occupy 9×10^-3 moles × 22.4/1 = 0.20 L
(c)
Suggest a reason why substance E does not conduct electricity in both solid and
molten states.
Answer:
Substance E does not conduct electricity in both solid and molten states because of very low melting and boiling points.
In both solid and molten state free electrons are required to conduct electricity. substance E has low boiling and melting point which means substance will have relatively weak bonds. Because of weak bonds substance E might not have much free electron in its outermost shell that can cause the electric current by their coordinated movement.
Hence, substance E is unable to conduct in both melting and molten state.
Visit the interactive periodic table and locate the element neon (Ne). Use the information within the square to answer these questions.
Answer:
What is the atomic number of neon?
10
What is the atomic mass of neon? Give your answer to the nearest tenth.
20.2
The periodic table is a representation of the periodic elements based on atomic numbers. The atomic number of neon is 10, and the atomic mass is 20.2 amu.
What are the properties of neon?Neon is categorized as a stable gas that belongs to the noble gas group. It has been represented as Ne and is a monoatomic gas with no odor or color. It has an atomic number of 10 and an electronic configuration as, [He] 2s²2p⁶.
The atomic mass of neon elements is 20.2 amu and is said to have full electrons per shell. They do not need to donate or accept any electron as they have a balanced orbital. They have the property of fluorescence and are used in electric signs and lamps.
Therefore, neon is placed in group 18 and has atomic number 10 and a mass of 20.2 amu.
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A base has a molarity of 1.5M w.R.T the hydroxyl ion concentration. If 7.35 cm3 of this base is taken and diluted to 147 cm3, then what is the concentration of the hydroxyl ion.
Answer:
0.077M is the concentration of the hydroxyl ion
Explanation:
Dilution factor is the ratio between the aliquot that is taken of a solution and the total volume of the diluted solution.
For the problem, dilution factor is:
7.53cm³ / 147cm³ = 0.05122
To obtain molarity of a diluted solution you must multiply dilution factor and initial molarity of the solution, thus:
1.5 M × 0.05122 = 0.077M is the concentration of the hydroxyl ion
1). Calculate the mass of hydrogen peroxide needed to obtain 0.460 L of oxygen gas at STP
2H2O2(aq) → 2H2O(l) + O2(g)
2) 1. Use the reaction shown to calculate the mass of iron that must be used to obtain 0.500 L of hydrogen at STP.
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Answer:
1) 1.39 grams H2O2
2) 0.933 grams Fe
Explanation:
Step 1: Data given
Volume of oxygen = 0.460 L
STP = 1 atm and 273 K
Step 2: The balanced equation
2H2O2(aq) → 2H2O(l) + O2(g)
Step 3: Calculate the number of moles O2
p*V = n*R*T
⇒with p= the pressure = 1 atm
⇒with V = the volume = 0.460 L
⇒with n = the number of moles = TO BE DETERMINED
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 273 K
n = (p*V)/(R*T)
n = (1 * 0.460)/ (0.08206*273)
n = 0.0205 moles moles
Step 4: Calculate moles H2O2
For 2 moles H2O we'll have 2 moles H2O and 1 mol O2
For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2
Step 5: Calculate mass H2O2
Mass H2O2 = moles H2O2 * molar mass H2O2
Mass H2O2 = 0.041 moles * 34.01 g/mol
Mass H2O2 = 1.39 grams
Step 1: Data given
Volume of hydrogen = 0.500 L
STP = 1 atm and 273 K
Step 2: The balanced equation
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Step 3: Calculate the moles of H2
p**V = n*R*T
⇒with p= the pressure = 1 atm
⇒with V = the volume = 0.500 L
⇒with n = the number of moles = TO BE DETERMINED
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 273 K
n = (p*V) / '*T)
n = (1 * 0.500) / (0.08206 * 273)
n = 0.0223 moles
Step 4: Calculate moles Fe
For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2
For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe
Step 5: Calculate mass of Fe
Mass Fe = moles Fe * atomic mass Fe
Mass Fe = 0.0167 moles * 55.845 g/mol
Mass Fe = 0.933 grams Fe
1. The mass of the hydrogen peroxide should be 1.39 grams H2O2.
2) The mass of the iron should be 0.933 grams Fe.
Calculation of the mass:Since
Volume of oxygen = 0.460 L
STP = 1 atm and 273 K
Now The balanced equation
2H2O2(aq) → 2H2O(l) + O2(g)
Now the number of moles O2
p*V = n*R*T
Here p= the pressure = 1 atm
V = the volume = 0.460 L
n = the number of moles = ?
R = the gas constant = 0.08206 L*atm/mol*K
T = the temperature = 273 K
Now
n = (p*V)/(R*T)
n = (1 * 0.460)/ (0.08206*273)
n = 0.0205 moles moles
Now moles H2O2 should be
For 2 moles H2O we'll have 2 moles H2O and 1 mol O2
So,
For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2
Now mass H2O2
Mass H2O2 = moles H2O2 * molar mass H2O2
Mass H2O2 = 0.041 moles * 34.01 g/mol
Mass H2O2 = 1.39 grams
2. The mass of the iron should be
Since
Volume of hydrogen = 0.500 L
STP = 1 atm and 273 K
Now
The balanced equation
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Now the moles of H2
p**V = n*R*T
Here
p= the pressure = 1 atm
V = the volume = 0.500 L
n = the number of moles = ?
R = the gas constant = 0.08206 L*atm/mol*K
T = the temperature = 273 K
So,
n = (p*V) / '*T)
n = (1 * 0.500) / (0.08206 * 273)
n = 0.0223 moles
Now Calculate moles Fe
For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2
So,
For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe
Now the mass of Fe
Mass Fe = moles Fe * atomic mass Fe
Mass Fe = 0.0167 moles * 55.845 g/mol
Mass Fe = 0.933 grams Fe
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