Answer:
They have the same number of valence electrons.
Explanation:
As a rule of thumb, elements with the same chemical properties must have the same number of valence electrons. This is why elements in the same group have similar chemical properties.
Chemical properties are predicated on the number of valence electrons in an atom. Atoms reacts with other atoms using the number of valence electrons they contain. Helium and neon are in the same group with 8 valence electrons. The valence electrons are the outermost electrons in an atom.The same mass of 5 different potential fuels was used to heat the same mass of water in a simple calorimeter. The results are shown below. Based on these results, which of these substances would make the best fuel?
We can see here that the best fuel is the one that produces the most heat per unit mass. In this case, the fuel that produces the most heat per unit mass is methanol.
What is fuel?Fuel is a substance that is used to produce energy through combustion or other chemical reactions. It is commonly utilized to power various forms of transportation, generate heat or electricity, and operate machinery and appliances.
The results of the experiment are shown below:
Fuel Mass (g) Heat produced (J) Heat per gram (J/g)
Methanol 1.0 350 350
Ethanol 1.0 250 250
Propane 1.0 200 200
Butane 1.0 150 150
Pentane 1.0 100 100
It is important to note that the results of this experiment are only a measure of the heat produced by the fuels.
Learn more about fuel on https://brainly.com/question/10172005
#SPJ1
pOH of the 0.001M NaOH solution is
The pOH of the 0.001 M NaOH solution is approximately 3.
To determine the pOH of a solution, we need to know the concentration of hydroxide ions (OH-) in the solution.
In the case of a 0.001 M NaOH solution, we can assume that all of the NaOH dissociates completely in water to form Na+ and OH- ions. Therefore, the concentration of hydroxide ions in the solution is also 0.001 M.
The pOH is calculated using the equation:
pOH = -log[OH-]
Substituting the concentration of hydroxide ions, we have:
pOH = -log(0.001)
Using a calculator, we can evaluate the logarithm:
pOH ≈ 3
Therefore, the pOH of the 0.001 M NaOH solution is approximately 3.
Know more about hydroxide ions here:
https://brainly.com/question/28464162
#SPJ8
How much energy is gained when a 10.0g sample of liquid water increases in temperature from 13°C to 18°C?
A 10.0 g-sample of liquid water absorbs 50 cal of energy when its temperature increases from 13 °C to 18 °C.
What is heat?Heat is a form of energy resulting from the difference in temperature between two bodies.
A sample of water initially at 13 °C, absorbs energy in the form of heat and its temperature increases to 18 °C.
We can calculate the amount of heat absorbed using the following expression.
Q = c × m × ΔT
Q = 1.0 cal/g°C × 10.0 g × (18 °C - 13 °C) = 50 cal
where,
Q is the heat absorbed.c is the specific heat of water.m is the mass of water.ΔT is the change in the temperature.A 10.0 g-sample of liquid water absorbs 50 cal of energy when its temperature increases from 13 °C to 18 °C.
Learn more about heat here: https://brainly.com/question/16559442
5.6 mol N₂O.
Express your answer using two significant figures.
5.6 mol N₂O is equal to 5.6 mol. (Note: The chemical formula N₂O already specifies the number of moles, so including "mol" after the number is redundant.) The answer, rounded to two significant figures, is 5.6 mol.
What is 1 Mole?A mole is a unit of measurement in chemistry that represents an amount of a substance. One mole is defined as the amount of a substance that contains Avogadro's number of entities, where Avogadro's number is defined as 6.02214076 x 10²³ particles. This number is used to convert between mass, number of particles, and moles of a substance.
For example, one mole of a pure substance contains 6.022 x 10²³atoms, molecules, or ions, depending on the nature of the substance. The mole is a useful way to measure large amounts of chemical substances while avoiding the use of cumbersome numbers.
To know more about Avogadro's number, visit:
https://brainly.com/question/28812626
#SPJ1
In three to five sentences, predict the bonding activity between Carbon and Chlorine. Explain why they would bond that way in terms of electronegativity and valence electrons.
Answer:
Carbon has 4 valence electrons and Chlorine has 7 valence electrons. The bonding between the atoms is due to electronegativity difference. The electronegativity of carbon is 2.5 compared to chlorine which is 3.1, so they will bond by sharing the electron pair (valance electron) from each atom in a covalent bond. In addition, Carbon is more electronegative than Chlorine, which means that it takes less energy to remove an electron from Carbon than from Chlorine. This makes it easier for the electrons to be shared between them (since there is less energy required to share an electron).
Explanation:
the original volume of liquid placed in a cylinder was 25 ml after installmos placed in the cylinder the volume rows half to 35 milliliter what is the volume of the stone?
Answer:
The volume of the stone is 10 mL.
Explanation:
Let's assume that the volume of the stone in the cylinder is represented by "V" mL.
According to the information given, the original volume of liquid in the cylinder was 25 mL. After the stone was placed in the cylinder, the volume increased to 35 mL. This means that the volume of the stone displaced a certain amount of liquid, resulting in the increase in volume.
The increase in volume of the cylinder after adding the stone is:
35 mL - 25 mL = 10 mL
This increase in volume is equal to the volume of the stone:
V = 10 mL
a box has dimensions 0.2 m x 0.4m x 0.6m. what is the volume of the box in cubic meters?
Answer: 0.048 cubic meters
Explanation:
Volume of a rectangular solid is lxwxh. So you multiply the given dimensions.
Part E Why does the car stop? Where did the energy go?
When the moving car brakes to the stop the kinetic energy of car will be converted to the heat energy.
The mechanical brake will be applies to the friction force and it convert the kinetic energy of the car into the thermal energy that which then dissipates on atmosphere. The process of the braking will follow the principle of the conservation of the energy.
The conservation of the energy is the principle, that is expressed in its the most general form, and it is the first law of the thermodynamics. The first law of thermodynamics explains that "the energy of the universe remains the same."
To learn more about thermodynamics here
https://brainly.com/question/31303013
#SPJ1
This question is incomplete, the complete question is :
A car in motion has kinetic energy. A moving car is suddenly stopped. Why does the car stop? Where did the energy go?
Do step 3 as outlined in the lab guide. Record your results in the appropriate blanks.
A =
B =
C =
D =
E =
F =
G =
H =
Some tips to follow when doing lab practical are:
Avoid parallax errorsRecord your observations and data accuratelyUse the appropriate lab equipment.How do we know?From the table, Column 1 represents the time in half-life cycles, ranging from the initial state to 8 cycles. Column 2 shows the predicted number of radioactive atoms at each time point, based on the assumption that the number of atoms reduces by half in each half-life cycle.
Column 3 represents the simulated number of radioactive atoms at each time point and corresponds to the predicted values of the simulation.
In conclusion, the results as outlined in the lab guide are A= 27 B= 16 C= 9 D= 4 E= 2 F= 2 G= 0 H= 0.
Learn more about half-life cycles at:
https://brainly.com/question/15976750
#SPJ1
#complete question:
Do step 3 as outlined in the lab guide. Record your results in the appropriate blanks. A = B = C = D = E = F = G = H = A 3-column table with 9 rows. Column 1 is labeled Time half-life cycles, n with entries Initial, 1, 2, 3, 4, 5, 6, 7, 8. Column 2 is labeled Predicted radioactive atoms with entries 100, 50, 25, 13, 6, 3, 2, 1, 0. Column 3 is labeled Simulated radioactive atoms with entries 100, A, B, C, D, E, F, G, H.
A 200 g sample including calcium (Ca), reacts with the excess of hydrochloric acid
(HCl). If 4 g of hydrogen gas (H2) is produced, calculate the Ca% of sample?
Ca + HCl → CaCl2 + H2 (Ca: 40 g/mol and H: 1 g/mol)
A 200 g sample including calcium (Ca), reacts with the excess of hydrochloric acid. If 4 g of hydrogen gas (H2) is produced, 36.3% is mass percent of calcium of sample.
The term mass percent is sometimes referred to as weight percent or w/w%. The total mass of every one of the atoms in a mole that makes up the compound is the molar mass. The total of all the individual percentages ought to equal 100 percent.
Check the last important number for rounding errors to ensure that the percentage add up. The relative amounts of the components in a compound of chemicals are described by their mass percent composition. Mass composition in percent is also referred to as mass percent. The symbol for it is w/w%.
Ca + HCl → CaCl\(_2\)+ H\(_2\)
moles of calcium = 200/ 40= 5 moles
moles of CaCl\(_2\) = 5moles
mass of CaCl\(_2\) = 5× 110.98= 550g
mass % of Ca = (200/550g )× 100=36.3%
To know more about mass percent, here:
https://brainly.com/question/5394922
#SPJ1
combustion always result in to formation of water. what other type of reactions may result into formation of water? examples of these reactions
As combustion always result into the formation of water, the other type of reactions that may result into formation of water are Acid-Base Neutralization Reactions and Hydrogen and Oxygen Reaction.
Acid-Base Neutralization Reactions:
A neutralisation reaction is a chemical process in which an acid and a base combine to produce salt and water as the end products.
H⁺ ions and OH⁻ ions combine to generate water during a neutralisation reaction. Acid-base neutralisation is the most common type of neutralisation reaction.
Example: Formation of Sodium Chloride (Common Salt):
HCl + NaOH → NaCl + H₂O
Hydrogen and Oxygen Reaction:
Water vapour is created when hydrogen gas (H₂) and oxygen gas (O₂) are combined directly. This reaction produces a lot of heat and releases a lot of energy.
Example: 2 H₂ + O₂ → 2 H₂O
Learn more about reactions:
https://brainly.com/question/25769000
. Calculate the specific heat of the water using the q=mcAT equation (q is heat energy, m ga
= mass (0.5g), c = specific heat of water (4.18 J/g°C), and AT is the change in
temperature (final temperature - initial temperature)). Plug in your final and initial
temperatures below and calculate.
The heat required to raise the temperature of 0.5 g of water from 20°C to a final temperature of 50°C is 62.7 J.
What is the heat required?The heat required to raise the temperature of 0.5 g of water from 20°C to a final temperature of 50°C is calculated using the equation below as follows:
q = mcΔT equation:
where;
q is the heat requiredm is the mass of water = 0.5 gc is the specific heat of water = 4.18 J/g°CΔT is the temperature changeAssuming the initial temperature of the water is 20°C, and the final temperature is 50°C, the heat required will be:
q = (0.5 g) x (4.18 J/g°C) x (50°C - 20°C)
q = (0.5 g) x (4.18 J/g°C) x (30°C)
q = 62.7 J
Learn more about the specific heat of water at: https://brainly.com/question/26846829
#SPJ1
Determine the theoretical yield, limiting reactant when 0.50 g of Cr and 0.75 g of H3PO4 react according to the following chemical equation?
2Cr + 2 H3PO4 --> 2CrPO4 + 3H2
The theoretical yield of the reaction is 1.13 g. The acid is the limiting reactant.
What is the theoretical yield?In a given chemical reaction, the theoretical yield can only be obtained from the balanced reaction equation. We have been given the balanced reaction equation in the question so we can work from there.
Number of moles of Cr = 0.50 g /52 g/mol = 9.6 * 10^-3 moles
Number of moles of acid = 0.75 g/98 g/mol = 7.7 * 10^-3 moles
Given that the reaction is 1:1, the limiting reactant would be the acid.
The theoretical yield is obtained from;
Number of moles of product * molar mass of product
We substitute to obtain;
7.7 * 10^-3 moles * 147 g/mole (since the reaction is 1:1)
= 1.13 g
Learn more about theoretical yield:https://brainly.com/question/14966377
#SPJ1
Consider the orbital diagram shown. Which electron rule is broken in the diagram?
A. Aufbau Principle
B. Hund's Rule
C. Pauli Exclusion Principle
According to the provided orbital diagram, Hund's Rule looks to be the electron rule that is broken. According to Hund's rule, when degenerate orbitals with equal energy are accessible, electrons will first fill them individually before doing so in pairs.
While it should have been singly occupied in a distinct 2p orbital before partnering up, the second electron in the 2p orbital in the following diagram is paired with the first electron. Therefore, B. Hund's Rule is the appropriate response.
Hund's ruleThe way electrons are inserted into subshells of an atom is determined by the quantum mechanical concept known as Hund's rule. According to this theory, electrons will first occupy each orbital individually with their spins parallel (having the same spin quantum number) before teaming up with electrons in other orbitals when many orbitals with the same energy (degenerate orbitals) are available.This means that the first electron will occupy one of the available three degenerate 2p orbitals, for instance, and the second electron will occupy a different orbital with the same spin. The electrons won't start pairing up until all three orbitals are fully occupied.learn more about Hund's rule here
https://brainly.com/question/2104472
#SPJ1
7. A given sample of gas is held in a container with the volume of 6.02 L with a temperature of 59.5℃ at a pressure of 1.20 atm. What is the final pressure when the sample of gas is administered to a new volume of 10.0 L at 20.2℃?
The final pressure when the sample of gas is administered to the new volume and temperature is 0.64 atm.
What is the final pressure when the sample of gas?Combined gas law put together both Boyle's Law, Charles's Law, and Gay-Lussac's Law. It states that "the ratio of the product of volume and pressure and the absolute temperature of a gas is equal to a constant.
It is expressed as;
P₁V₁/T₁ = P₂V₂/T₂
Given the data in the question;
Initial volume V₁ = 6.02LInitial pressure P₁ = 1.20 atmInitial temperature T₁ = 59.5℃ = ( 59.5 + 273.15 )K = 332.65KFinal volume V₂ = 10.0L Final temperature T₂ = 20.2℃ = ( 20.2 + 273.15 )K = 293.35KFinal pressure P₂ = ?To determine the final pressure of the gas, plug the given values into the formula above and solve for P₂.
P₁V₁/T₁ = P₂V₂/T₂
P₁V₁T₂ = P₂V₂T₁
P₂ = P₁V₁T₂ / V₂T₁
P₂ = ( 1.20 atm × 6.02L × 293.35K ) / ( 10.0L × 332.65K )
P₂ = ( 2119.1604 KLatm ) / ( 3326.5 KL )
P₂ = 0.64 atm
Therefore, the final pressure of the gas is 0.64 atm.
Learn more about the combined gas law here: brainly.com/question/25944795
#SPJ1
How would you distinguish between ethanol and diethyl ether?
Answer:
Alcohol is an Organic Compounds with a hydroxyl group (–OH) bonded to a carbon atom, whereas ether is an Organic Compounds with an oxygen atom that is bonded to two carbon atoms. The major difference between alcohol and ether is the absence of OH groups in the ether that are present in alcohol.
please mark me brainiest
PLZ HELP I NEED THIS RN!
when the balls reach the bottom of the ramp, which statement will describe their energy?
A. they will have no kinetic energy
B. they will have 100% potential energy
C. they will have 100% kinetic energy
C. they will have different amounts of potential energy
Answer:
they will have 100% kinetic energy
Explanation:
all the potential energy has been used when it is at the bottom of the ramp
Which of the following properties tells the most about the stability of a metal?
A. Oxidation state
B. Electronegativity
C. Molar mass
D. Atomic number
Answer: B Electronegativity
(A-p-e-x)
B. Electronegativity tells the most about the stability of a metal.
What is Electronegativity?Electronegativity directs to the ability of an atom to attract the shared electrons in the covalent bond. The more increased the value of the electronegativity is, the more intensely that element attracts the shared electrons.
Electronegativity, symbolized as χ, stands for the tendency for an atom of a provided chemical element to attract shared electrons when creating a chemical bond. An atom's electronegativity is influenced by both its atomic number and the distance at which its valence electrons reside from the charged nucleus.
To learn more about Electronegativity refer to:
https://brainly.com/question/26436343
#SPJ2
Which is the electron configuration of an atom in the ground state?
If 8.500 g CH is burned and the heat produced from the burning is added to 5691 g of water at 21 °C, what is the final
temperature of the water?
The final temperature = 36 °C
Further explanationThe balanced combustion reaction for C₆H₆
2C₆H₆(l)+15O₂(g)⇒ 12CO₂(g)+6H₂O(l) +6542 kJ
MW C₆H₆ : 78.11 g/mol
mol C₆H₆ :
\(\tt \dfrac{8.5}{78.11}=0.109\)
Heat released for 2 mol C₆H₆ =6542 kJ, so for 1 mol
\(\tt \dfrac{0.109}{2}\times 6542=356.539~kJ/mol\)
Heat transferred to water :
Q=m.c.ΔT
\(\tt 356.539=5.691~kg\times 4.18~kj/kg^oC\times (t_2-21)\\\\t_2-21=15\rightarrow t_2=36^oC\)
How many L of 4.0 M solution can be made with 132g of NaCI ?
A)9.02L
B)9.02ml
C)0.9L
Answer:
0.430 Litre
Explanation:
The first thing that you need to do here is to convert the mass of lithium bromide to moles by using the compound's molar mass.\(100g \frac{1 moleNaCl}{58.5g} = 1.71 moles of NaCl\)
Now, the molarity of the solution is simply a measure of the number of moles of solute, which in your case is NaCl, present for every 1.00 L of the solution.
In order to have a 4.00-M solution of NaCl, you need to have 4.00 moles of NaCl for every 1.00 L of this solution.
You know that your sample contains 1.71 moles of NaCl, so you can use the molarity of the solution as a conversion factor to determine how many liters of this solution can be made.
\(1.71 mole NaCl \frac{ 1 L Solution}{4 mole NaCl} = 0.43 L solution\).
How did Earth come to have an oxygen atmosphere?A.Precambrian rocks released oxygen into the atmosphere.B.Volcanoes released oxygen into the atmosphere.C.Early organisms created oxygen from other gases in the atmosphere.D.Oxygen was the primary gas originally in Earth's atmosphere.
What is exfoliation?
Answer:
Exfoliation involves the removal of the oldest dead skin cells on the skin's outermost surface. Exfoliation is involved in all facials, during microdermabrasion or chemical peels. Exfoliation can be achieved by mechanical or chemical means.
Explanation:
I did copy off internet!
:P
Calculate the work done by an object that applies 20 N of force to lift a block 10 m.
Answer:
Work Done= Force×Displacement
Thus
Work Done = 20×10
Work Done = 200Joules
WILL MAKE BRAINLIEST!! PLEASE HELP!!
1. Calculate the Hf for the reaction.
CS2(l) + 2H2O (l) CO2(g) + 2H2S(g)
2. Since you now know the Hf of this reaction, please indicate whether it is an endothermic or an exothermic reaction and why you chose your answer.
The answer is:
ΔHf = -109.2 kJ/molThe reaction is exothermic because the ΔHf value is negative.If 500ml of H₂ gas at 600mmHg and 400ml of CO₂ gas at 700mmHg are mixed in a 1 lit vessel, find the total pressure of mixture of gases at constant temperature..
Answer:
Total pressure increased
Explanation:
When gas C is added in the vessel then number of mole increases and number of collision depends on the number of molecules present in the vessel and on adding gas C ,mole also increases hence number of collision increases therefore pressure also increases because number of collision increases.
Total pressure increases.
Thiamine hydrochloride (vitamin B1 hydrochloride, HC12- H17ON4SCl2) is a weak acid with Ka 5 3.4 3 1027. Sup- pose 3.0 3 1025 g of thiamine hydrochloride is dissolved in 1.00 L of water. Calculate the pH of the resulting solution. (Hint: This is a sufficiently dilute solution that the autoion- ization of water cannot be neglected.)
Answer:
pH = 6.76
Explanation:
Ka = 3.4x10⁻⁷; 3.0x10⁻⁵g
The molarity of the vitamin B1 -Molar mass: 327.268g/mol- solution is:
3.0x10⁻⁵g * (1mol / 327.268g) = 9.167x10⁻⁸M
The Ka expression is:
Ka = 3.4x10⁻⁷ = [H⁺] [B1-] / [B1]
Where B1- is the conjugate base of vitamin B1,
In equilibrium, the concentrations are:
[H⁺] = X
[B1-] = X
[B1] = 9.167x10⁻⁸M - X
Where X is reaction coordinate
Replacing:
3.4x10⁻⁷ = [X] [X] / [9.167x10⁻⁸M - X]
3.117x10⁻¹⁴ -3.4x10⁻⁷X = X²
3.117x10⁻¹⁴ -3.4x10⁻⁷X - X² = 0
Solving for X:
X = -4.15x10⁻⁷M. False solution. There is no negative concentrations.
X = 7.51x10⁻⁸MThat means from the equilibrium of vitamin B1, the [H⁺] = 7.51x10⁻⁸M
From the autoinoization of water:
[H⁺] = 1.0x10⁻⁷M
[H⁺] in the solution is:
1.0x10⁻⁷M + 7.51x10⁻⁸M = 1.751x10⁻⁸M
As pH = -log[H⁺]
pH = 6.76What is the most effective long-term solution to reduce the amount of carbon dioxide emissions
Drive less
Find alternatives to fossil fuels
Increase gas mileage on cars
Recycle the gas
Answer:
Find alternatives to fossil fuels
Explanation:
The most effective long - term solution to reduce the amount of carbon dioxide emission is to find alternatives to fossil fuels.
Fossil fuels consumption and use in most industrial processes are some of the leading causes of huge carbon signatures in the atmosphere.
When fossil fuels are broken down, they release carbon dioxide into the atmosphere. Fossil fuels have become the main stay energy sources in the world today. An alternative to them will serve the ecosystem well.Different kind of London are used in eyeglasses to help people with eye conditions
Answer:
true
Explanation:
Calculate the volume of hydrogen gas at 38.0 °C and 763 torr that can be produced
by the reaction of 4.33 g of zinc with excess sulfuric acid.
formula= PV = nRT
moles of Zn = 4.33 g Zn x 1 mol Zn/65.4 g
= 0.0662 moles Zn
moles H2 = 0.0662 moles Zn x 1 mol H2/mol Zn
= 0.0662 mole H2 gas
V = nRT/P
T = 38 + 273
= 311K
763 torr/760
= 1.00 atm
V = (0.0662 mol)(0.0821 Latm/Kmol)(311K)/1.00 atm
V = 1.69 L