To determine the percentage of oxygen in the molecule we must first know its structure and how many oxygen atoms are contained in it. The structure of aluminum phosphate is AlPO4.
It means that there are 4 oxygen atoms, 1 Aluminum atom, and 1 phosphate atom.
Now we will determine the weight of the molecule AlPO4 by adding the atomic weights of the elements as follows:
Element Atomic mass # of atoms Mass
Al 26.9815 1 26.9815
P 30.9738 1 30.9738
O 15.999 4 63.996
Total mass of AlPO4 = 26.9815+30.9738+63.996 = 121.9513 g/mol
Now we will determine the mass percentage with the following equation:
[tex]\text{Mass percentage = }\frac{Oxygen\text{ mass}}{\text{Total mass of the molecule }}\times100[/tex]We replace the known terms:
[tex]\begin{gathered} \text{Mass percentage = }\frac{63.996}{\text{121.9513 }}\times100 \\ \text{Mass percentage = }52.477 \end{gathered}[/tex]So, the percentage of oxygen in aluminum phosphate is 52.477%
The x-ray has a frequency
of 1.4 x 1019 Hz. What is the
energy associated with one
x-ray? ►
The energy of the photon is 9.24 * 10^-15 J.
What is the energy?Let us recall that the energy has to do with the product of the frequency and the plank's constant. In thus case, we have the frequency of the photon and we have to find the energy of the photon and we have to do that from the following formula;
E = hf
E = energy of the photon
h = Plan's constant
f = frequency of the photon
Then;
E = 6.6 * 10^-34 Js * 1.4 x 10^19 Hz
E = 9.24 * 10^-15 J
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What is the volume of a 10% m/v aqueous solution that contains 37.8g of HN03?
378mL is the volume of a 10% m/v aqueous solution that contains 37.8g of HN03
What is an aqueous solution?
A solution in which the solvent is water is referred to as an aqueous solution. By adding (aq) to the appropriate chemical formula, it is typically shown in chemical equations. For instance, Na+(aq) + Cl would be used to represent a table salt solution (also known as sodium chloride, or NaCl) in water (aq).
The word aqueous, which derives from the Latin word aqua, means being or consisting of water. Water is a common solvent in chemistry because it works great as a solvent and is also readily available. In experiments, water is frequently used as the solvent; therefore, unless otherwise specified, the term "solution" refers to an aqueous solution.
The mass of HNO3 = 37.8g
The mass is 10% m/v of the solution which implies
10/100 = mass/ volume
Volume = 10mass
Volume = 10(37.8g)
Volume = 378mL
Thus, 378mL is the volume of a 10% m/v aqueous solution that contains 37.8g of HN03
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What is a nonrenewable resource?
Non-renewable resources are resources found by humans as a source of energy and such resources cannot be replenished. Therefore, such resources should not be wasted.
Nature is the epitome of beauty and grace but as humans grow up they forget the shining and uplifting virtues. People should use resources responsibly. Non-renewable resources come from the earth. The supply is finite and could take billions of years to replenish.
In the past, many non-renewable energies were relatively cheap to generate. However, as supplies continue to dwindle the cost of this extraction is likely to increase, prompting customers to turn to alternative power sources such as solar and wind. The most common examples of natural resources include crude oil coal uranium and mineral resources such as gold. A subset of non-renewable resources includes crude oil and natural gas. Both substances are made of organic carbon materials and change shape over time after being heated and compressed.
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5.Which of the following statements is true of the particles found in gas?Select one:a. They are closely spaced and not very energetic.b. They are closely spaced and very energetic.c. They are far apart and not energetic.d. They are very far apart and very energetic.
Answer
d. They are very far apart and very energetic.
Explanation
The particles in the solid are touching with very little space between them. The particles in a liquid usually are still touching but there are some spaces between them. The gas particles have big distances between them.
Gas particles are in constant rapid motion in random directions. The fast motion of gas particles gives them a relatively large amount of kinetic energy.
What is the pH of a 0.59 M solution of potassium nitrite (KNO2)?
Report your answer to 2 decimal places.
From the calculation that is based on the ICE table shown, the pH of the solution is 1.8.
What is the pH?Let us recall that the KNO2 is a salt of the nitrous acid. Our concern now would be on the nitrous ion and we are going to make up the ICE table from the following;
NO2^-(aq) + H2O(l) ⇄ HNO2(aq) + OH^-(aq)
HNO2 (aq) ⇄ H^+(aq) + NO2^-(aq)
I 0.59 0 0
C -x +x +x
E 0.59 -x x x
Now we know that the Ka of HNO2 is 4.0x10^-4.
Ka = [H^+] [NO2^-]/[ HNO2]
4.0x10^-4 = x^2/0.59 -x
4.0x10^-4(0.59 -x) = x^2
2.36 x10^-4 - 4.0x10^-4x = x^2
x^2 + 4.0x10^-4x - 2.36 x10^-4 = 0
x=0.015
pH = -log(0.015)
pH = 1.8
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What triggers the development of a tornado?
A.
unstable Coriolis forces
B.
water vapor rising too quickly from the ocean
C.
the colliding of two cold fronts
D.
a cold air mass colliding with a hot air mass
A cold air mass colliding with a hot air mass triggers the development of a tornado and is denoted as option D.
What is Tornado?
This is referred to as a violently rotating column of air and it is caused as a result of different types of factors such as the humidity , temperature etc.
A tornado is usually very violent and it is formed when cold air mass collides with a hot air mass and is often characterized by a green color in most situations and is therefore the reason why option D was chosen as the most appropriate choice.
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How many ml. of pepsi are there in a 2.55 quart bottle of pepsi?
Step 1 - Converting ml and quart
As can be seen in the figure, the conversion factor is:
[tex]1000ml=1.057qt[/tex]Dividing both sides by 1.057:
[tex]946.07ml=1qt[/tex]Step 2 - Converting 2.55 quart to ml
Now that we know the conversion factor, we just have to multiply both sides by 2.55:
[tex]\begin{gathered} 2.55\times946.07ml=2.55\times1qt \\ \\ 2.55qt=2412.47ml \end{gathered}[/tex]There are thus 2412.47 ml in a 2.55 quart bottle pepsi.
2KClO₃(s) → 2KCl(s) + 3O₂(g) 15. How many liters of O₂ will be produced at a temperature of 37OC and 1520 torr if 2 moles of KClO₃ decompose according to the balanced equation given above:
The volume of 79.1 liters of oxygen (O₂) will be produced at a temperature of 370°C and 1520 torr if 2 moles of KClO₃ decompose.
What is the molar volume of the gas?The molar volume (Vm) is the volume occupied by 1 mole of a chemical element or a chemical compound at Standard Temperature and Pressure (STP). Molar gas volume is one mole at a specific temperature and pressure and has a fixed volume.
The Molar volume is inversely proportional to density and directly proportional to molar mass. One mole of any gas at STP occupies a volume of 22.4 liters.
Given, the 2moles of KClO₃ will produce O₂ gas = 3moles
The volume occupied by 3 moles of the oxygen gas at 370°C and 1520 torr is :
Given, n = 3, P = 1520 torr = 2atm and T = 370°C = 643 K
PV = n RT
(2atm) V = (3)(0.082 atm L /K) (643K)
V =79.1 L
Therefore, the volume of oxygen gas produced will be equal to 79.1 Litres.
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Nuclear energy is produced and converted at nuclear power plants.
Which kind of nuclear energy is used in homes?
light energy
electrical energy
solar energy
heat energy
Nuclear energy produces electricity or electrical energy that can be used to power homes, schools, businesses, and hospitals.
What is Nuclear energy ?A type of energy emitted by an atom's nucleus, which is composed of protons and neutrons, is known as nuclear energy. Fission, which occurs when atoms' nuclei split into numerous portions, and fusion, which occurs when nuclei fuse together, are the two methods in which this type of energy can be created.
Nuclear power plants turn water into steam in a controlled setting using heat produced by nuclear fission, which drives generators to generate electricity.Nuclear energy is recyclable even though it is not a renewable energy. 96% of the spent nuclear fuel in reactors is recyclable thanks to Orano's innovations, which are unparalleled in the world on an industrial scale.Learn more about Nuclear energy here:
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Which compound is a carbohydrate? (1 point)
O HCIO4
O Na₂C₂04
O C4H12N2
O C3H6O3
Answer:
it's the last one
Answer:
C3H6O3
Explanation:
It is one of the simplest molecules to compare against other molecules, such as sugars and amino acids.
During a physics experiment, an electron is accelerated to 93 percent of the speed of light. What is the speed of the electron in miles per hour? (speed of light = 3.00 x 10^8 m/s, 1 km = 0.6214 mi)
speed of the electron = 0.93*speed of light
= 0.93*3.00 × [tex]10^{8}[/tex] m/s*(0.6214 mi/1 km)*(3600 s/hr)
= 6.24X [tex]10^8[/tex] mi/hr
What is speed?
Speed is defined as the rate at which the position of an object changes in any direction.
There are four types of speed and they are:
Constant Speed: An object is at a constant Speed when the object travels the same distance in equal intervals of time. Variable Speed: An object is said to have variable speed when the object travels varying distances at regular intervals. Average Speed: Average speed is defined as the constant speed obtained by dividing the total distance travelled by the object by the total time spent on the object. Instantaneous Speed : When an object moves with a variable speed, the speed of the object at any instant of time is called the instantaneous speed.To learn more about speed, visit;
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Balance the equation: __Rh + __O2 --> __Rh2O7
Answer:
[tex]4Rh+7O_2\text{ }\rightarrow2Rh_2O_7[/tex]Explanation:
Here, we want to balance the given chemical equation
We can start by balancing the oxygen atoms
We have 7 on the left and 2 on the right
To make a balance, we place 7 before the molecular oxygen on the left and 2 on the given oxide
That means we would be having 4 Rh on the left
To balance the Rh, we have to place 4 on the left side
Thus, we have the balanced equation as:
[tex]4Rh+7O_2\text{ }\rightarrow2Rh_2O_7[/tex]What is the pH of an aqueous solution if the [H3O+] = 0.055 M?
Answer
pH = 1.26
Explanation
If the [H3O+] of an aqueous solution is 0.055 M, then its pH can be calculated using the pH formula below.
[tex]\begin{gathered} pH=-log[H_3O^+] \\ \\ pH=-log(0.055) \\ \\ pH=-(-1.26) \\ \\ pH=1.26 \end{gathered}[/tex]The pH of an aqueous solution of 0.055 M is 1.26
Question 5
2 Points
The composition of a mixture of potassium chlorate and potassium chloride is to be determined. A 9.47 gram sample of the mixture
is heated until the creation of oxygen gas stops. If the sample mass after heating is 7.11 grams, what is the percent by mass of
potassium chlorate in the mixture? Report your answer with 3 significant figures.
Add your answer
The percent by mass of potassium chlorate in the mixture is 62.46 %
Potassium chlorate is a compound containing potassium, chlorine and oxygen, with the molecular formulation KClO₃. In its natural form, it is a white crystalline substance. After sodium chlorate, it's far the second one maximum not unusual chlorate in commercial use.
Potassium chloride, also referred to as potassium salt, is used as a medicine to treat and prevent low blood potassium. Low blood potassium may also occur due to vomiting, diarrhea, or certain medications.
A aggregate is a material made of two or more extraordinary chemical materials which are not chemically bonded. A combination is the bodily aggregate of two or greater substances wherein the identities are retained and are combined in the shape of answers, suspensions and colloids
KClO₃ + KCl = 9.47 gram --------- sample before heating
KClO₃ + KCl = 7.11 gram ---------- sample mass after heating
mass of oxygen = 9.47 - 7.11 = 2.36 gram
Therefore mass of KClO₃ in an mixture is = 7.11/2 + 2.36
= 5.915 gram
Therefore, the percent by mass of potassium chlorate in the mixture = 5.915/9.47 × 100
= 62.46 %
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Marine science table 20-2
The distance between two consecutive crests or troughs of a wave, particularly in the case of electromagnetic or sound waves, is known as its wavelength.
The wavelength (in nanometers) or frequency of light is used to quantify it (in Hertz). Like with radio waves, they can also be as long as centimetres or metres. It is represented by and inversely proportional to wave frequency.
What distinguishes frequency from wavelength?
Frequency and wavelength are intimately related, particularly in the context of light. Frequency is determined by the number of waves that pass through a single place over a particular period of time, whereas wavelength is the distance between two successive troughs or crests.
The crest of a wave is the part of transverse waves that are above the mean level. The wave's trough is the region of transverse waves that lies below the mean level. The distance between two succeeding crests or troughs is known as the wavelength.
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11. Which of the following is true at equilibrium?a.The reaction stopsb. The forward and reverse reactions occur at equal ratesC. The reactants have been used upd. The products have been used up
Explanation:
Equilibrium occurs in a reversible reaction. This occurs when in a reaction the products formed react to reproduce the reactants. So basically, the forward and reverse reaction occur at equal rates.
Answer:
The correct answer is B.
PLEASE HELP!
In a monomolecular reaction A->B , at t =250C, the initial concentration decrease at 25% in t =52 min. Calculate:
a) the constant rate;
b) the time after the initial concentration decrease with 75%;
c) the initial reaction rate, if the initial concentration of the reactant is 2.5 mol/L·s.
1) The rate at which this reaction occurs is obtained as 9.22 * 10^-5 s-1
2) The time that the reaction takes is obtained as 15033 s
3) The initial reaction rate is 9.22 * 10^-5 M
Can we find the rate of reaction?To obtain the rate of reaction is to find the rate at which the reactants move on to become products.
In this case there is reduction of the amount by 25% in 52 min.
Hence;
Initial concentration [A]o = [A]oFinal concentration = [A]o - 0.25 [A]o = 0.75 [A]oTime taken = 52 min or 3120 sUsing the approach of first order kinetics;
ln[A] = -kt + ln[A]0
k = -(ln[A] - ln[A]0)/t
k = - (ln0.75 [A]o/A]0)/3120
k = 9.22 * 10^-5 s-1
b) It was given in the question that;
[A] = [A]o - 0.75 [A]o = 0.25 [A]o
ln[A] = -kt + ln[A]0
t = -(ln[A] - ln[A]0)/k
t = - (ln0.25 [A]o/A]0)/9.22 * 10^-5
t = 15033 s
c) When the initial rate is is 2.5 mol/L·s
k = - (ln0.25 (2.5)/ln(2.5))/15033
k = 9.22 * 10^-5 M
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The substances that make it up keep their physical properties
Answer:
A mixture is a combination of two or more substances in any proportions. The substances in a mixture do not combine chemically, so they retain their physical properties. A homogeneous mixture has the same composition throughout.
Why are elements on the periodic table not arranged by mass
Periodic table give us a chart where we can see the elements in the increasing order of atomic number because of the repetition of the properties of the elements
What is Periodic table?Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
Arrangements of element is done on the basis of atomic number not on the basis of mass number because on arranging on the basis of atomic number the properties of elements gets repeat due to the arrangement of electron around the nucleus.
Thus periodic table is arranged on the basis or atomic number not on the basis of mass number due to repetition of properties
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What is a nonrenewable resource?
Non-renewable resources are resources found by humans as a source of energy and such resources cannot be replenished. Therefore such resources should not be wasted.
The earth is rich in resources. Some are unlimited others are inherently limited. Renewable resources are unlimited and can be replenished. However non-renewable resources are finite and must be used carefully to ensure long-term use for future generations. Wood is a renewable resource. This means you can grow additional resources in place of felled wood.
Non-renewable energy comes from resources that are depleted or not replenished over and over again throughout our lifetime. Most non-renewable energy sources are fossil fuels such as coal oil and natural gas. Carbon is the main element of fossil fuels. Air and water are also renewable natural resources. They don't grow like trees or have babies like animals. But they are constantly updated. They move cyclically.
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Why is an indicator used in a titration?To help reactants react successfully.To bind to the acid to form products.To show when the reaction has reached or past the equivalence point.To provide a surface for the reaction to occur.
Explanation:
The use of pH indicators in the titration process is useful to determine the end point of the titration, indicating that the entire sample is reacted.
Answer: To show when the reaction has reached or past the equivalence point.
Fictitious element Az has two common isotopes. What is the average atomic mass (in amu) of Az given that seven-ninth of the isotopes have a mass of 325.2 amu, while the rest have a mass of 329.6 amu? Report the answer to 4 significant figures.
The average atomic mass of the fictitious element Az is 326.2 amu
The average atomic mass (on occasion referred to as atomic weight) of an element is the weighted average mass of the atoms in an obviously going-on sample of the element. average masses are typically expressed in unified atomic mass gadgets.
The atomic mass of detail is the common mass of the atoms of an element measured in the atomic mass units (AMU, also called daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of every isotope is improved via the abundance of that specific isotope.
The atomic mass is a median of an element's atomic hundreds, weighted via the herbal abundance of each isotope of that detail. it is a weighted common because exclusive isotopes have one-of-a-kind hundreds. An atomic mass unit is 1/12th of the mass of a 12C atom.
Average atomic mass = Σ % abundance × mass
= 325.2 × 7/9 + 329.6 × 2/9
= 252.93 + 73.24
= 326.17 amu
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1s² 2s²2p6 is the electron configuration of
The electron configuration 1s² 2s²2p6 is the element Neon.
Which four different electron configurations are there?One orbital may house a maximum of two electrons, and there are four different types of orbitals (s, p, d, and f). More electrons can be held in the p, d, and f orbitals since they contain various sublevels. As was said, each element's location on the periodic table determines the specific electron configuration of that element.
The octet rule states that an atom's outermost shell may hold no more than 8 electrons (except K shell which can accommodate maximum 2 electrons). Hence, potassium's electrical structure.
The quantity of valance electrons, which take part in the creation of a chemical bond, is found in an atom's outermost shell. The outermost shell of the atom's electrical structure contains 4 valance electrons.
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If the pH of an acid is 5.1, what is the concentration of the H+?
Answer
[H+] = 7.94x10^-6 M
Explanation
Given:
pH = 5.1
Required: The concentration of H+
Solution
pH = -log[H+]
5.1 = - log [H+]
[H+] = 10^-5.1
[H+] = 7.94x10^-6 M
It reacts with oxygen according to the following equation:
B2H6(g)+3O2(g)→B2O3(s)+3H2O(l)
How many grams of diborane will react with 7.1 mol of O2 ?
Taking into account the reaction stoichiometry, 65.32 grams of B₂H₆ will react with 7.1 mol of O₂.
Reaction stoichiometryIn first place, the balanced reaction is:
B₂H₆ + 3 O₂ → B₂O₃ + 3 H₂O
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
B₂H₆: 1 moleO₂: 3 molesB₂O₃: 1 moleH₂O: 3 molesThe molar mass of the compounds is:
B₂H₆: 27.6 g/moleO₂: 32 g/moleB₂O₃: 69.6 g/moleH₂O: 18 g/moleThen, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
B₂H₆: 1 mole ×27.6 g/mole= 27.6 gramsO₂: 3 moles ×32 g/mole= 96 gramsB₂O₃: 1 mole ×69.6 g/mole= 69.6 gramsH₂O: 3 moles ×18 g/mole= 54 gramsMass of B₂H₆ requiredThe following rule of three can be applied: If by reaction stoichiometry 3 moles of O₂ react with 27.6 grams of B₂H₆, 7.1 moles of O₂ react with how much mass of B₂H₆?
mass of B₂H₆= (7.1 moles of O₂× 27.6 grams of B₂H₆)÷ 3 moles of O₂
mass of B₂H₆= 65.32 grams
Finally, 65.32 grams of B₂H₆ is required.
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Which period 2 element would the 4th ionization energy be much larger than the 3rd ionization energy?
Period 2 element would the 4th ionization energy be much larger than the 3rd ionization energy is Boron.
Boron belongs to period second. atomic no. of boron is 5 and the electronic configuration is given as :
B₅ = 1s² 2s² 3p₁
The 1st ionization energy = 800.6
the 2nd ionization energy = 2427.1
the 3rd ionization energy = 3659.7
the 4th ionization energy = 25025.8
So. we can see that the 3rd ionization energy is much lower than 4th ionization energy because after removing the 3rd electron from 2s boron will attain the stable electronic configuration of helium. now to remove electron from filled orbital it will require much larger energy the 3rd ionization energy.
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HELP DUE TOMORROWWWW ILL GIVE BRAINLIEST
Answer:
Thermal energy refers to the energy contained within a system that is responsible for its temperature. Heat is the flow of thermal energy. A whole branch of physics, thermodynamics, deals with how heat is transferred between different systems and how work is done in the process (see the 1ˢᵗ law of thermodynamics).
Thermodynamics, and many other related fields, phase transitions are the physical processes of transition between a state of a medium, identified by some parameters, and another one, with different values of the parameters.
A sample of gas with an initial volume of 28.4 L at a pressure of 724 mm Hg and a temperature of 303 K is compressed to a volume of 15.5 L and warmed to a temperature of 379 K. What is the final pressure of the gas?
To solve this question, we need to use the combined gas equation which is given as
[tex]\begin{gathered} \frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2} \\ p=\text{pressure} \\ v=\text{volume} \\ t=\text{temperature} \end{gathered}[/tex]Now we should write down the given data
[tex]\begin{gathered} v_1=28.4l \\ p_1=724\operatorname{mm}hg \\ T_1=303K \\ v_2=15.5L \\ T_2=379K \\ p_2=\text{ ?} \end{gathered}[/tex]So, we would use the previous equation i wrote down.
[tex]\begin{gathered} \frac{p_1v_1}{t_1}=\frac{p_2v_2}{t_2} \\ \frac{724\times28.4}{303}=\frac{p_2\times15.5}{379} \\ 67.8600=\frac{p_2\times15.5}{379} \\ 15.5p_2=67.86\times379 \\ 15.5p_2=25718.94 \\ \text{divide both sides by the coefficent of p2} \\ \frac{15.5p_2}{15.5}=\frac{25718.94}{15.5} \\ p_2=1659.28\operatorname{mm}hg \end{gathered}[/tex]From the calculations above, the final pressure of the gas is 1659.28mmHg
what is the molality of a solution contain 82.6g of butane dissolved in 0.500kg of hexane
Considering the definition of molality, the molality of a solution that contain 82.6g of butane dissolved in 0.500kg of hexane is 2.84 moles/kg.
Definition of molalityMolality is a measure of chemical concentration that indicates the amount of a substance dissolved in a given mass of solvent.
In other words, molality is the number of moles of solute that are dissolved in 1 kilogram of solvent.
The Molality of a solution is determined by the expression:
molality= number of moles of solute÷ kilograms of solvent
Molality is expressed in units moles/kg.
Molality in this caseIn this case, you know:
Mass of butane= 82.6 gramsMass molar of butane= 58 g/moleNumber of moles= Mass of butane÷ Mass molar of butane= 1.42 molesKilograms of solvent= 0.500 kgReplacing in the definition of molality:
molality= 1.42 moles÷ 0.500 kg
Solving:
molality= 2.84 moles/kg
Finally, the molality of the solution is 2.84 moles/kg.
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The forensic technician at a crime scene has just prepared a luminol stock solution by adding 10.0 g of luminol into a total volume of 75.0 mL of H2O .What is the molarity of the stock solution of luminol?Express your answer with the appropriate units.
1) List the known and unknown quantities.
Sample: luminol.
Mass: 10.0 g.
Volume: 75.0 mL.
Molarity: unknown.
2) Set the equation.
[tex]M=\frac{moles\text{ }of\text{ }solute}{liters\text{ }of\text{ }solution}[/tex]3) Conversion of units.
3.1-Convert mass to moles.
The molar mass of luminol (C8H7N3O2) is 177.1601 g/mol.
[tex]mol\text{ }C_8H_7N_3O_2=10.0\text{ }g\text{ }C_8H_7N_3O_2*\frac{1\text{ }mol\text{ }C_8H_7N_3O_2}{177.1601\text{ }g\text{ }C_8H_7N_3O_2}[/tex][tex]mol\text{ }C_8H_7N_3O_2=0.05645\text{ }mol\text{ }C_8H_7N_3O_2[/tex]3.2-Convert mL to L.
1 L = 1000 mL
[tex]L=75.0\text{ }mL*\frac{1\text{ }L}{1000\text{ }mL}=0.075\text{ }L[/tex]4) Plug in the known quantities.
[tex]M=\frac{0.05645\text{ }mol\text{ }C_8H_7N_3O_2}{0.075\text{ }L}[/tex][tex]M=0.7527\text{ }M\text{ }C_8H_7N_3O_2[/tex]The molarity of the stock solution is 0.75 M C8H7N3O2.
.