Answer:
phosphorus is more reactive than calcium
Explanation:
The [H3O+] concentration in the rainwater of pH = 4.35 is:
The concentration of H3O+ in rainwater with a pH of 4.35 is approximately 3.548 x 10^(-5) M.
Explanation:The concentration of H3O+ in rainwater with a pH of 4.35 can be calculated using the equation pH = -log[H3O+]. Rearranging the equation to solve for [H3O+], we have [H3O+] = 10^(-pH). Substituting the given pH value into the equation, we find that the [H3O+] concentration is approximately 3.548 x 10^(-5) M.
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At 273K and 1.00 atm pressure, a sample of gas occupies 30.0 mL. If the temperature is increased to 303K and the entire gas sample is transferred to a 20.0 mL container, what will be the gas pressure inside the container?
Answer:
1.66 atm
Explanation:
P1V1/T1 = P2V2/T2
1.00atm*30.0mL/273K= P2*20.0 mL/303K
P2 = (1.00*30.0*303)/(273*20.0) = 1.66 atm
Fission and Fusion of Atomic Nuclei:
Please help! 26 points
Will mark brainliest to correct answers
1. What happens in a chain reaction?
A) Products that start a new reaction are released.
B) Reactants that have two parts split
C) Products that are radioactive are lost
D) Radioactive reactants are deposited on control rods
2. Which type of coolant(s) usually is (are) used to remove heat from nuclear reactor core?
A) water only
B) liquid sodium only
C) liquid sodium or water
D) CFCs
3. A reaction that results in the combining of smaller atomic nuclei is ___.
A) chemical
B) fission
C) fussion
D) ionization
4. What does neutron absorption accomplish in a nuclear reactor?
A) It slows down the reaction.
B) It speeds up the reaction
C) It increases the rate of heat absorption
D) It recycles the fuel
Answer:
C B A D
Explanation:
1. A) Products that start a new reaction are released.
2. C) liquid sodium or water
3. C) fusion
4. B) It speeds up the reaction.
1. In a chain reaction, the products of one reaction are capable of initiating further reactions. Specifically, in a nuclear chain reaction, the fission of a heavy nucleus (such as uranium-235) releases neutrons, which can then go on to cause the fission of other nuclei. This is a self-sustaining series of reactions where the products (neutrons) start new reactions. Hence, option A is correct.
2. Nuclear reactors can use different types of coolants to transfer the heat generated by the nuclear reactions to the turbines or to the environment. The most common coolants are water (in light-water reactors) and liquid sodium (in fast-breeder reactors). Therefore, option C, which states liquid sodium or water, is the correct answer.
3. A reaction where smaller atomic nuclei combine to form a heavier nucleus is known as fusion. This is different from fission, which is the splitting of a heavy nucleus into smaller nuclei. Chemical reactions involve the rearrangement of electrons in atoms or molecules, not the combining or splitting of atomic nuclei. Ionization is the process of adding or removing charged particles to or from an atom or molecule, but it does not involve the combining or splitting of nuclei. Thus, the correct answer is option C, fusion.
4. Neutron absorption is a critical part of the operation of a nuclear reactor. When a neutron is absorbed by a fissile nucleus (like uranium-235), it can cause that nucleus to become unstable and split, releasing energy and more neutrons. This process is what sustains the chain reaction in a nuclear reactor. The absorption of neutrons by fissile material effectively speeds up the reaction by increasing the rate of fission events. Therefore, option B, It speeds up the reaction, is the correct answer."
What does image 2 show?
Answer:
A GALAXY WIITH I YHINK MANY
Explanation:
If 20.5 g of chlorine is reacted with 20.5 g of sodium, which reactant is in excess?
Answer: [tex]Na[/tex] is in excess.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} Cl_2=\frac{20.5g}{71g/mol}=0.29mol[/tex]
[tex]\text{Moles of} Na=\frac{20.5g}{23g/mol}=0.89moles[/tex]
[tex]2Na(s)+Cl_2(g)\rightarrow 2NaCl(s)[/tex]
According to stoichiometry :
1 mole of [tex]Cl_2[/tex] require 2 moles of [tex]Na[/tex]
Thus 0.29 moles of [tex]Cl_2[/tex] will require=[tex]\frac{2}{1}\times 0.29=0.58moles[/tex] of [tex]Na[/tex]
Thus [tex]Cl_2[/tex] is the limiting reagent as it limits the formation of product and [tex]Na[/tex] is the excess reagent.
calculate Qsp for calcium fluoride (Ksp= 3.9x10^-11) when 125.0 mL of a 0.00615 M solution of Ca(NO3)2 is added to 330.0 mL of a 0.00615 M solution of KF
The reaction quotient, Qsp, for calcium fluoride when 125.0 mL of a 0.00615 M solution of Ca(NO3)2 is added to 330.0 mL of a 0.00615 M solution of KF is 0.000034 M^3.
Explanation:The question requires the calculation of the reaction quotient, Qsp, for calcium fluoride (CaF2) which is the indexing of a point in time during the reaction. The formula for this reaction is [Ca+]^n [F-]^m. Given that we are mixing a 125.0 mL of 0.00615 M solution of calcium nitrate (Ca(NO3)2) with a 330.0 mL of 0.00615 M solution of potassium fluoride (KF), we have to first calculate the volume of the total solution which becomes 125+330 = 455 mL or 0.455 L. The concentrations of Ca^2+ and F^- are given by the molarity of the Ca(NO3)2 and KF solutions respectively. Thus, Qsp = [Ca^2+]{2}[F^-]{2}.
Here, [Ca2+] = [0.00615 M *(125/455)] = 0.0017 M and [F-] = [0.00615 M *(330/455)] = 0.0045 M. Qsp = (0.0017)(0.0045)^2 = 0.000034 M^3. So, the reaction quotient, Qsp, for calcium fluoride (CaF2) equals 0.000034.
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The Qsp of calcium fluoride when 125.0 mL of a 0.00615 M solution of Ca(NO3)2 is added to 330.0 mL of a 0.00615 M solution of KF is calculated to be 3.47 x 10^-11 by first finding the molarity of each ion in the solution and then using these molarity values in the equation for Qsp.
Explanation:First, we find the total volume of the mixture which is 455.0 mL (125.0 mL + 330.0 mL). To find the molarity of each ion, we divide the moles of each ion by the total volume. Given that each ion comes from a 0.00615 M solution, the moles of each ion (Ca²+ and F¯) are (0.00615 mol/L)(0.125 L) and (0.00615 mol/L)(0.33 L) respectively. The molarity of these ions then comes out to be 0.00170 M for Ca²+ and 0.00451 M for F¯.
Next, we obtain the Qsp which is calculated similar to Ksp by multiplying the concentrations of the dissolved ions raised to their stoichiometric coefficients. However, unlike Ksp, the ion concentrations are not necessarily equilibrium values. For calcium fluoride, CaF2, it dissolves into one Ca²+ ion and two F¯ ions. So, Qsp = [Ca²+][F¯]² = (0.00170)(0.00451)² = 3.47 x 10^-11.
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The pressure of nitrogen gas at 35°C is changed from 0.89 atm to 4.3 atm. What will be its final temperature in Kelvin?
Answer: The final temperature in Kelvin is 1488
Explanation:
To calculate the final temperature of the system, we use the equation given by Gay-Lussac Law. This law states that pressure of the gas is directly proportional to the temperature of the gas at constant pressure.
Mathematically,
[tex]\frac{P_1}{T_1}=\frac{P_2}{T_2}[/tex]
where,
[tex]P_1\text{ and }T_1[/tex] are the initial pressure and temperature of the gas.
[tex]P_2\text{ and }T_2[/tex] are the final pressure and temperature of the gas.
We are given:
[tex]P_1=0.89atm\\T_1=35^0C=(35+273)K=308K\\P_2=4.3atm\\T_2=?[/tex]
Putting values in above equation, we get:
[tex]\frac{0.89}{308}=\frac{4.3}{T_2}\\\\T_2=1488K[/tex]
Hence, the final temperature in Kelvin is 1488
If 16.00 g of O₂ reacts with 80.00 g NO, what is the excess reactant? *
A.O₂
B.NO
Answer:
B. NO
Explanation:
In each mole of NO, the weight of the oxygen is 16.00 g; the weight of the nitrogen is 14.01 g. Then in 80 g of NO, we have 42.65 g of oxygen and 37.35 g of nitrogen.
__
In each mole of NO₂, the weight of the oxygen is 2(16.00) = 32 g. The weight of the nitrogen is 1(14.01) = 14.01 g.
From the available oxygen, we can produce ...
(42.65 g +16 g)/(32.00 g/mol) = 1.83 mol of NO₂
From the available nitrogen, we can produce ...
(37.35 g)/(14.01 g/mol) = 2.67 mol of NO₂
Clearly, the reaction is limited by the amount of available oxygen.
NO is the excess reactant.
__
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Why are many scientists concerned about humans adding large amounts of carbon to the atmosphere by burning fossil fuels (combustion)
Answer:
The reason why scientists are concerned about the amount of CO2 released into the atmosphere by burning fossil fuels is because CO2 is a greenhouse gas.
Explanation:
Greenhouse gases help keep the Earth warm. They trap infrared radiation, or heat energy. This makes them useful at certain levels; but if there is too much of them, they will cause global warming rates to increase, melting ice packs, thereby causing rising sea levels. Rising sea levels are a major threat tp humanity right now. New projections and satellite readings suggest that more than 150 million people's homes will be submerged by 2050, with some cities even being completely submerged. Other than rising sea levels, excessive amounts of greenhouse gases also cause loss of biodiversity, changes in wildlife behavior, and shifts in periodic biological phenomena.
Answer:
The atmosphere has a limited capacity to absorb and recycle carbon naturally.
Explanation:
The carbon cycle tends to recycle carbon—moving it in and out of the atmosphere—at certain rates. If too much carbon is released into the atmosphere, this carbon will surpass the cycle's ability to remove it. This will result in the amount of carbon in the atmosphere increasing.
Why do the words “Shake well before using” indicate that the fruit juice in a carton is a suspension? What are these words not used on a milk container?
Answer:
It indicates it is a suspension b/c in a suspension heavy particles separate or fall and the ingredie-nts would need to be mixed after sinking.
and for the milk one I'm not sure but I think when u shake milk well it may change into a butter.
Because some of the larger particles in a suspension will eventually settle out.
What are suspensions?Suspensions are defined as a mixture that is heterogeneous, meaning the solid particles are dispersed throughout the liquid without really dissolving in it. The friction between the tires of your car and the pavement is increased by suspension systems. It is possible to steer your car more steadily and enjoy more comfortable handling by increasing friction. You can drive more securely and safely the more contact your tires have with the road.
The fact that the ingredients would need to be mixed after sinking suggests that it is a suspension. For the milk one, I'm not sure, but I believe that when milk is shaken thoroughly, it may transform into butter.
Thus, because some of the larger particles in a suspension will eventually settle out.
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What is a jet stream?
Answer:
Jet streams are fast flowing, narrow, meandering air currents in the atmospheres of some planets, including Earth
Explanation:
Answer: I hoped this helped, all I had to do was Google it though
Examples of laboratory rules.
Explanation:
1. Wear Personal Protective Equipments.
2. Do not eat or drink in the laboratory.
3. No horseplaying.
4. No running around.
5. Do not leave any experiments that involve fire unattended.
6. Treat every chemicals as if it is dangerous even if it's just water.
A sailor pulls a boat along a dock using a rope. How much work does the sailor do if he exerts a force of 255 N on the rope and pulls the boat 11.4 m?
Answer:
The work done is 2,907 J
Explanation:
Work is one of the forms of energy transmission between bodies. To perform a job, you must exert a force on a body and it moves. In other words, when a force is applied to a body and it moves, work is done.
The work is equal to the product of the force by the distance and by the cosine of the angle that exists between the direction of the force and the direction that the moving point or object travels:
W = F * d * cos α
In the International System of Units the Force is expressed in newtons and the distance in meters, so the work will have units of newtons. Meter = joules (J).
In this case:
F= 255 Nd= 11.4 mα=0Replacing:
W= 255 N* 11.4 m* cos 0
Solving:
W= 255 N* 11.4 m* 1
W= 2,907 J
The work done is 2,907 J
The work done by the sailor is 2907 joules (J).
To calculate the work done by the sailor, we can use the formula for work:
[tex]\[\text{Work} = \text{Force} \times \text{Distance} \times \cos(\theta)\][/tex]
where:
- [tex]\(\text{Force}\)[/tex] is the force exerted by the sailor,
- [tex]\(\text{Distance}\)[/tex] is the distance over which the force is applied,
- [tex]\(\theta\)[/tex] is the angle between the force and the direction of movement.
If the force is applied in the direction of the movement, [tex]\(\theta = 0\)[/tex] degrees and [tex]\(\cos(0) = 1\)[/tex].
Given:
- [tex]\(\text{Force} = 255 \, \text{N}\)[/tex]
- [tex]\(\text{Distance} = 11.4 \, \text{m}\)[/tex]
- [tex]\(\theta = 0\)[/tex] degrees (assuming the force is in the direction of the movement)
Substitute these values into the formula:
[tex]\[\text{Work} = 255 \, \text{N} \times 11.4 \, \text{m} \times \cos(0)\][/tex]
[tex]\[\text{Work} = 255 \, \text{N} \times 11.4 \, \text{m} \times 1\][/tex]
[tex]\[\text{Work} = 2907 \, \text{J}\][/tex]
using the equation PCl5(g)=PCl3(g)+Cl2(g), if PCl5 is removed, what will the equilibrium shift?
The system will shift towards the reactant's side.
What is an empirical formula?A chemical formula showing the simplest ratio of elements in a compound rather than the total number of atoms in the molecule
[tex]PCl_5[/tex] (g) is removed. As [tex]PCl_5[/tex] (g) is removed/concentration decreases, the equilibrium will shift to oppose the change.
According to principle when the concentration of reactant decreases, the equilibrium shift towards the reactant side.
Hence, equilibrium will shift towards reactants.
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Final answer:
If PCl5 is removed from the equilibrium PCl5(g) = PCl3(g) + Cl2(g), the equilibrium will shift to the left to replace the removed PCl5, according to Le Châtelier's Principle.
Explanation:
Using the equation PCl5(g) = PCl3(g) + Cl2(g), if PCl5 is removed, the equilibrium will shift toward the left to replace the removed PCl5. This is because, according to Le Châtelier's Principle, when a component of a reaction at equilibrium is removed, the equilibrium will shift in the direction that tends to replace that component. In this reaction, removing PCl5 decreases its concentration, thus the system shifts left to increase its concentration by converting PCl3 and Cl2 back into PCl5.
Examine the following equations.
A. 23490Th→23491Pa+0−1e+γ
B. 60∗27Co→6027Co+γ
C. 23490Th→23088Ra+42He
D. 146C→147N+0−1e
Which equation or equations represent gamma decay?
A and D
D
C
C and D
A
A and B
B
Answer:
A and B
Explanation:
This is because there was emission of gamma (Y) radiations in both the reactions.
Choose all the answers that apply. Which of the following energy forms are involved in a nuclear power plant?
heat
sound
electrical
nuclear
mechanical
Answer:
nuclear, heat and electrical
Explanation:
Answer:
electrical
nuclear
mechanical
Explanation:
I know it is right. TRUST.
A compound that has a sea of delocalized electrons has what type of bonding?
A. Covalent bonding
B. Electrostatic bonding
C. Metallic bonding
D. Electrofluid bonding
Answer:
C. Metallic bonding
Explanation:
Which represents a balanced nuclear equation?
Superscript 23 subscript 11 upper N a right arrow superscript 24 subscript 12 upper M g plus superscript 1 subscript 1 upper H.
Superscript 24 subscript 11 upper N a right arrow superscript 24 subscript 12 upper M g plus superscript 0 subscript negative1 e.
Superscript 24 subscript 11 upper A l right arrow superscript 24 subscript 12 upper M g plus superscript 0 subscript negative 1 e.
Superscript 23 subscript 12 upper M g right arrow superscript 24 subscript 12 upper M g plus superscript 1 subscript 0 e.
Answer:
B ) Superscript 24 subscript 11 upper N a right arrow superscript 24 subscript 12 upper M g plus superscript 0 subscript negative1 e.
Explanation:
Answer:
its b
Explanation:
A new electricity generating plant wants to avoid using any nonrenewable energy resource to produce electricity. Which energy resource should the plant not use?
Answer:
Fossil fuel
Explanation:
Fossil fuel is defined as deposits of organic materials. It is usually formed from decayed plants and animals which has been converted to crude oil, coal, natural gas, or heavy oils due to exposure to heat and pressure over a very long period of time which ranges between hundreds of millions of years.
Fossil fuels are the major sources non renewable energy which is used in the generation of electricity.
5.00 L of air at 750 mmHg pressure was compressed into a 3.00 L steel cylinder. What is the final pressure? (round to significant figures)
Answer:
P2 = 1250mmHg
Explanation:
V1 = 5.0L
P1 = 750mmHg
V2 = 3.0L
P2 = ?
According to Boyle's law, the volume of a fixed mass of gas is inversely proportional to its pressure provided that temperature remains constant.
P = k/V k = P*V
P1*V1 = P2*V2 = P3*V3 =........=Pn*Vn
P1 *V1 = P2 * V2
Solve for P2
P2 = (P1 * V1) / V2
P2 = (750 * 5.0) / 3.0
P2 = 3750 / 3
P2 = 1250mmHg
The final pressure of the gas is 1250mmHg
What is a way that individuals can help slow climate change?
A. All of these
B. Turn off appliances you aren’t using.
C. Plant trees.
D. Bike instead of driving.
How many grams of HF are needed to react with 3.0 moles of Sn?*
10 points
→ SnF2 + H2
Sn + 2 HF
O 309
O 609
120g
2409
Answer: 120 grams of HF are needed to react with 3.0 moles of Sn
Explanation:
The balanced chemical equation is :
[tex]SnF_2+H_2\rightarrow Sn+2HF[/tex]
According to stoichiometry:
1 mole of [tex]Sn[/tex] reacts with 2 moles of HF
Thus 3.0 moles of Sn will react = [tex]\frac{2}{1}\times 3.0=6.0[/tex] moles of HF
Mass of [tex]HF=moles\times {\text {molar mass}}=6.0mol\times 20.01g/mol=120g[/tex]
Thus 120 grams of HF are needed to react with 3.0 moles of Sn
What is the pOH of a solution that has a pH of 3.85
Answer:
10.15
Explanation:
14-3.85=pOH
- Hope that helps! Please let me know if you need further explanation.
If a container is filled with 13.3 L of gas at 1.41 atm. The container is held at constant temperature throughout the experiment if the pressure changes to 1.02 atm what will the final volume be
Answer:
The final volume is 18.38 L.
Explanation:
It is given that,
A container is filled with 13.3 L of gas at 1.41 atm. The container is held at constant temperature throughout the experiment if the pressure changes to 1.02 atm.
It is based on Boyle's law. According to this law, at constant temperature,
[tex]PV=K[/tex]
K is constant
[tex]P_1V_1=P_2V_2[/tex]
[tex]V_2=\dfrac{P_1V_1}{P_2}\\\\V_2=\dfrac{13.3\times 1.41}{1.02}\\\\V_2=18.38\ L[/tex]
So, the final volume is 18.38 L.
What is the function of each of these muscles?
stapedius:
sartorius:
gluteus maximus:
Final answer:
The stapedius muscle stabilizes the stapes bone in the ear, the sartorius aids in hip and knee movements, and the gluteus maximus extends the femur at the hip joint.
Explanation:
The muscles mentioned each have specific functions:
The stapedius muscle is the smallest skeletal muscle in the human body and it serves to stabilize the stapes bone in the ear to prevent damage to the inner ear from loud noises.The sartorius is the longest muscle in the human body; it facilitates the flexion, abduction, and lateral rotation of the hip, as well as the flexion of the knee, which enables movements like crossing the legs.The gluteus maximus is the largest muscle in the gluteal region and it extends the femur at the hip joint, enabling activities like climbing stairs or standing up from a sitting position.The intrinsic skeletal muscles of the back and neck, along with the muscles of the abdominal wall and thorax, help maintain posture, facilitate movement, and stabilize different parts of the body's trunk.
How many atoms are present in 55 grams of iron
To find the number of atoms present in 55 grams of iron, we need to convert grams to moles and then use Avogadro's number to convert moles to atoms.
Explanation:To find the number of atoms present in 55 grams of iron, we need to convert grams to moles and then use Avogadro's number to convert moles to atoms. The molar mass of iron is 55.8 g/mol. Therefore, 55 grams of iron is equal to:
55 g / 55.8 g/mol = 0.986 moles of iron.
Since 1 mole of any substance contains Avogadro's number (6.022 x 10^23) of particles, the number of atoms in 0.986 moles of iron is:
0.986 mol x (6.022 x 10^23 atoms/mol) = 5.93 x 10^23 atoms of iron.
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There are [tex]$\boxed{1.20 \times 10^{24}}$[/tex] atoms of iron present in 55 grams of iron.
To determine the number of atoms in 55 grams of iron, we follow these steps:
1. First, we need to know the molar mass of iron. The molar mass of iron (Fe) is approximately 55.845 grams per mole.
2. Next, we use Avogadro's number, which is [tex]$6.022 \times 10^{23}$[/tex] atoms per mole, to find the number of atoms in one mole of iron.
3. Now, we calculate the number of moles in 55 grams of iron by dividing the mass of iron by its molar mass:
[tex]\[ \text{moles of iron} = \frac{\text{mass of iron}}{\text{molar mass of iron}} = \frac{55 \text{ g}}{55.845 \text{ g/mol}} \approx 1 \text{ mol} \][/tex]
4. Finally, we multiply the number of moles by Avogadro's number to find the total number of atoms:
[tex]\[ \text{number of atoms} = \text{moles of iron} \times \text{Avogadro's number} \] \[ \text{number of atoms} \approx 1 \text{ mol} \times 6.022 \times 10^{23} \text{ atoms/mol} \] \[ \text{number of atoms} \approx 6.022 \times 10^{23} \text{ atoms} \][/tex]
Since we have approximately 1 mole of iron, the number of atoms is approximately equal to Avogadro's number. Therefore, there are approximately [tex]$1.20 \times 10^{24}$[/tex] atoms of iron in 55 grams of iron, considering the minor rounding in the molar mass.
If 450.0 mL of a 0.500 M solution is mixed with 200.0 mL of water, what is the molarity of the new
solution?
A. 0.346 M
B. 0.625 M
C. 1. 86 M
D. 2.50 M
Answer:
Answer: A) .346 M
Explanation:
Given:
- 450 mL
- .5 M soln
-200 mL water
1) Convert mL to L
450 mL = .45 L
200 mL = .2 L
2) Find mols in solution
.5 M = x/.45 L
x = .225 mol
3) Find total volume of solution
.45 L + .2 L =.65 L
4) Find new molarity
molarity (M) = mols solute/ L solution
y = .225 mol (from step 2)/ .65 L (from step 3)
y = .346 M
Answer: A) .346 M
Explain why potassium chloride has the formula KCl, but potassium oxide is K2O (5)
Answer:
This has to do with the charge. The charge of K is +1. The charge of Cl is -1. I like to use a method called the criss cross method. So K+1 and Cl-1. I give each number to the other atom. (the "1" in Cl-1 goes to K the "1" in K+1 goes to Cl) so it becomes K1Cl1 which is KCl. Oxygen has a charge of 2-, so the 2 goes to the K and the 1 in K goes to the O, so it becomes K2O. Dm me if you want further explanation.
Explanation:
Final answer:
Potassium chloride consists of potassium and chloride ions, each with a 1+ and 1- charge, respectively, forming the formula KCl. Potassium oxide requires two potassium ions to balance the 2- charge of the oxide ion, resulting in the formula K₂O.
Explanation:
The reason why potassium chloride has the formula KCl but potassium oxide has the formula K₂O is based on the charges of the ions each metal and nonmetal forms. Potassium (K) forms a cation with a 1+ charge, while chloride (Cl) forms an anion with a 1- charge. To balance the charges, one potassium ion will pair with one chloride ion, resulting in the formula KCl, which has a neutral overall charge.
On the other hand, oxygen (O) forms an oxide anion with a 2- charge. To balance the charges, two potassium ions with a 1+ charge each are needed for every one oxide ion. This results in the chemical formula K₂O, as the two potassium ions balance out the charge of the one oxide ion, making the overall compound electrically neutral.
How many grams of oxygen are required to produce
9 grams of water at standard conditions?
2 H, + 0, → 2H20
grams
Answer:
4g
Explanation:
Equation of reaction
2H₂ + O₂ → 2H₂O
Molar mass of O2 = 16g/mol
Molar mass of water = 18g/mol
Number of moles = mass / molar mass
Mass = molar mass × number of moles
Mass of O2 = 1 × 16 = 16g
Mass of H2O = 2 × 18 = 36g
So from equation of reaction,
16g of O2 = 36g of H2O
X of O2 = 9g of H2O
X = (9 × 16) / 36
X = 4g
4g of O2 will produce 9g of H2O
A 5 g sample of lead (specific heat 0.129 /g˚C) is heated, then put in a calorimeter with 50 mL of water (specific heat 4.184 J/g˚C). The water temperature rises from 20∘C to 22∘C. If the lead sample’s final temperature was also 22∘C, what was the initial temperature of the lead sample?
Answer:
670.68°C
Explanation:
Given that:
volume of water = 50 ml but 1 g = 1 ml. Therefore the mass of water (m) = 50 ml × 1 g / ml = 50 g
specific heat (C) = 4.184 J/g˚C
Initial temperature = 20°C, final temperature = 22°C. Therefore the temperature change ΔT = final temperature - initial temperature = 22 - 20 = 2°C
The quantity of heat (Q) used to raise the temperature of a body is given by the equation:
Q = mCΔT
Substituting values:
Q = 50 g × 4.184 J/g˚C × 2°C = 418.4 J
Since the mass of lead = 5 g and specific heat = 0.129 J/g˚C. The heat used to raise the temperature of water is the same heat used to raise the temperature of lead.
-Q = mCΔT
-418.4 J = 5 g × 0.129 J/g˚C × ΔT
ΔT = -418.4 J / ( 5 g × 0.129 J/g˚C) = -648 .68°C
temperature change ΔT = final temperature - initial temperature
- 648 .68°C = 22°C - Initial Temperature
Initial Temperature = 22 + 648.68 = 670.68°C