Answer: D. Physical change
Explanation:
Phase changes are physical changes.
CHRYSan Chemical changes
musical anu nemal langes
Which option is an example of a chemical change?
O preparing a salad
mixing a salad dressing
O digesting a salad
O dicing an onion
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Answer:
I did this last year I'm so glad and I'm so happy to help you so it will be digesting a salad because if you look at the human body it breaks down as it goes into your body so if you eat it it doesn't look like it changed in front of your eyes but if you don't know it or not it breaks down inside of your organs so it will be digesting a salad
The ionic compound MX(s) is formed from the metal M(s) and the diatomic gas X2(g) at standard conditions. Calculate the lattice energy given the following data( data in picture)
The lattice energy of MX is 459.2 kJ/mol.
The lattice energy (ΔH° lattice) of an ionic compound is the energy released when one mole of the solid is formed from its constituent gaseous ions under standard conditions. The lattice energy is calculated using the Born-Haber cycle, which involves several steps including atomization, ionization, dissociation, and sublimation energies.
The lattice energy is related to the Coulombic attraction between the oppositely charged ions in the solid. To calculate the lattice energy for MX, we can use the following equation:
ΔH° lattice = ΔH° sub + ΔH° ion + ΔH° diss + ΔH° formation
where ΔH° sub is the sublimation energy of M(s), ΔH° ion is the first ionization energy of M(g), ΔH° diss is the dissociation energy of X2(g), and ΔH° formation is the enthalpy of formation of MX(s).
Using the given data, we can calculate each of these values and substitute them into the equation to obtain the lattice energy. The final answer should be in units of kJ/mol.
ΔH° sub (M) = 107.3 kJ/mol
ΔH° ion (M) = 577.5 kJ/mol
ΔH° diss (X2) = 242 kJ/mol
ΔH° formation (MX) = -467.6 kJ/mol
ΔH° lattice = 107.3 + 577.5 + 242 + (-467.6) = 459.2 kJ/mol
As a result, MX has a lattice energy of 459.2 kJ/mol.
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write the structural formula for 2-bromo-3-chloro-4,4-dimethylpentanal
Answer:
Br-CH2-CH(CH3)2-C(Cl)H-CH(CH3)2-CHO
Explanation:
The molecule has a total of 14 carbon atoms, 13 hydrogen atoms, and 1 bromine atom. The carbon atoms are arranged in a chain with a methyl group attached to the second carbon atom, a chlorine atom attached to the third carbon atom, and two methyl groups attached to the fourth carbon atom. The fifth carbon atom has a carbonyl group attached to it.
The molecule is an aldehyde, which means that it has a carbonyl group (C=O) at the end of the chain. The carbonyl group is polar, and the oxygen atom has a partial negative charge. The hydrogen atom has a partial positive charge. This polarity makes the aldehyde group susceptible to nucleophilic attack.
The bromine and chlorine atoms are both electrophilic, which means that they have a partial positive charge. This makes them susceptible to nucleophilic attack.
The methyl groups are non-polar and do not have any significant reactivity.
The molecule is a chiral molecule, which means that it has a mirror image that is not superimposable on itself. This is because the carbon atom with the carbonyl group is attached to four different groups.
The molecule is a liquid at room temperature and has a strong odor. It is used in a variety of products, including perfumes, flavorings, and plastics.
PLS HELP, IT’S DUE TODAY
In a nuclear fusion reaction, two small, light ___ (hydrogen atoms) combine under extreme __ and pressure to form one larger, heavier nucleus (helium).
Answer:
In a nuclear fusion reaction, two small, light 'nuclei' (hydrogen atoms) combine under extreme 'temperature' and pressure to form one larger, heavier nucleus (helium).
A student is researching how chemical reactions occur and how temperature impacts the rate of the reaction. She
measures how long it takes for 5 grams of calcite to dissolve in a strong solution of hydrochloric acid at different
temperatures. Her data is shown in the graph
Based on the data shown in the graph, the rate of reaction is directly proportional to the temperature of a reaction.
What is the rate of a reaction?The speed at which a chemical reaction occurs is called the reaction rate or rate of reaction. The rate of a reaction is proportional to the increase in product concentration per unit time and the decrease in reactant concentration per unit time.
The rate of a reaction is affected by the following:
the temperature of the reaction - the rate of reaction is directly proportional to the temperature of a reaction. Hence, the rate of a reaction increases with an increase in temperature.
presence of a catalyst - the rate of a reaction increases with the addition of a catalyst. A catalyst speeds up the rate of a reaction.
the surface area of the reactants - the rate of a reaction increases with an increase in the surface area of the reactants,
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Answer:
At higher temperatures, chemical reactions occur more quickly.
Explanation:
edmentum
Is benzene a solute or solvent
Scoring Scheme: 3-3-2-1 Part II. You considered the properties of two acid-base indicators, phenolphthalein and methyl orange. Many indicators are weak acids in water and establish the equilibrium: HIn(aq)(Color 1) H2O(l) H3O (aq) In-(aq)(Color 2). Indicators change color depending on whether they are in a protonated (HIn) or unprotonated (In-) form. What is the equilibrium expression for the phenolphthalein indicator in water and what colors are the protonated and unprotonated forms of the indicator
Answer:
Explanation:
Phenolphthalein is a protonated indicator and methyl orange is a basic indicator having hydroxyl ionisable part .
Phenolphthalein can be represented by the following formula
HPh which ionizes in water as follows
HPh + H₂O ⇄ H₃O⁺ + Ph⁻
( colourless ) ( pink )
In acidic solution it is in the form of protonated Hph form which is colourless
In basic medium , it ionises to give H₃O⁺ and unprotonated Ph⁻ whose colour is pink .
What is the mass of the silver sphere in kg?
Please I need help thank you
Answer:
its sodium hydroxide
Explanation:
Write a word equation for
H2O2 + liver
Answer:
h2o2 and liver produce oxygen gas
ca(hco3)2 molecular formula calculated
Answer:
C2H2CaO6
Explanation:
Ca same
H × 2
C × 2
O3 × 2
I hope this helps you :)
Which of the following statements best describes a limiting reactant? (5 points)
Answer:
The limiting reagent is the reactant that is completely used up in a reaction, and thus determines when the reaction stops. From the reaction stoichiometry, the exact amount of reactant needed to react with another element can be calculated.
Explanation:
The Reactant That Limits The Rate (or Speed) Of A Chemical Reaction. The Reactant That Can Produce The Greatest Amount Of Product.
The reactant that is used up before the others best describes a limiting reactant.
What is reactant?Reactant is a starting material in a chemical reaction.
What is limiting reactant?A limiting reactant is the reactant that is used up first and prevents more product from being made. When the limiting reactants are completely used up, then the reaction stops and no further products will be produced.Hence, the reactant that are used up before the others best describes a limiting reactant.
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when burning magnesium is lowered in a gas jar full of carbon 4 oxide it continued to burn explain
When burning magnesium is lowered in a gas jar full of carbon dioxide, the burning process continues because the carbon dioxide acts as an oxidizing agent.
What is a combustion reaction?A combustion reaction is a type of chemical reaction that occurs when a fuel, such as a hydrocarbon, reacts with an oxidizing agent, such as oxygen, to produce heat and light in the form of a flame. The basic equation for a combustion reaction is:
Fuel + Oxidant → Heat + Light + Products
In the case of burning magnesium, the fuel is magnesium and the oxidant is carbon dioxide. The products of the reaction are magnesium oxide and carbon dioxide. Combustion reactions are exothermic, meaning they release energy in the form of heat.
This means that the carbon dioxide provides the oxygen necessary for the combustion reaction to continue, allowing the magnesium to continue burning. Additionally, the carbon dioxide also helps to extinguish the flame by removing the heat and the oxygen from the combustion zone.
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How many particulars are present in 2 moles of water molecules?
Answer:
4 mole hydrozen and 2 mole oxyzen
Explanation:
A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is a stainless-steel cylinder that measures 27.0cm wide and 32.4cm high. The maximum safe pressure inside the vessel has been measured to be 3.10MPa. For a certain reaction the vessel may contain up to 0.218kg of carbon monoxide gas. Calculate the maximum safe operating temperature the engineer should recommend for this reaction. Write your answer in degrees Celsius. Round your answer to 3 significant digits.
Answer:
the maximum safe operating temperature the engineer should recommend for this reaction is 616 °C
Explanation:
Given the data in the question;
First we calculate the Volume of the steel cylinder;
V = πr²h
radius r = Diameter / 2 = 27 cm / 2 = 13.5 cm
height h = 32.4 cm
so we substitute
V = π × ( 13.5 cm )² × 32.4 cm
V = π × 182.25 cm × 32.4 cm
V = 18550.79 cm³
V = 18.551 L
given that; maximum safe pressure P = 3.10 MPa = 30.5946 atm
vessel contains 0.218kg or 218 gram of carbon monoxide gas
molar mass of carbon monoxide gas is 28.010 g/mol
so
moles of carbon monoxide gas n = 218 gram / 28.010 g/mol = 7.7829 mol
we know that;
PV = nRT
solve for T
T = PV / nR
we know that gas constant R = 0.0820574 L•atm•mol⁻¹ K⁻¹
so we substitute
T = ( 30.5946 × 18.551 ) / ( 7.7829 × 0.082 )
T = 567.5604 / 0.6381978
T = 889.317387 K
T = ( 889.317387 - 273.15 ) °C
T = 616.167 ≈ 616 °C { 3 significant digits }
Therefore, the maximum safe operating temperature the engineer should recommend for this reaction is 616 °C
write each of the following in scientific notation
1)1234
Answer:
1.234 × 10^3
Explanation:
hope this helps. . .<3
How many minutes will it take for a car to Travel 3.5 miles. If it is traveling 25km/h? (1 mile = 1.609 km) ?
Answer:
It will take the car 13.5 minutes to travel 3.5 miles.
Mg(s) + Ni2+(ag) -> Mg2+ (aq) + Ni(s) What is the total number of moles of electrons lost by Mg(s) when 2.0 moles of electrons are gained by Ni2+(ag)? * 10 ( 1.0 mol ,20 mol ,3.0 mol, 4.0 mol
The total number of moles of electrons lost by Mg(s) when 2.0 moles of electrons are gained by Ni2+(ag) is also 2.0 moles of electrons.
How to find the number of moles?This is because in a chemical equation, the number of moles of electrons gained by the reducing agent (in this case Ni2+) is equal to the number of moles of electrons lost by the oxidizing agent (in this case Mg(s)).
In this redox reaction, Mg is being oxidized because it loses electrons and Ni is being reduced because it gains electrons. The oxidation and reduction process are occurring simultaneously, so the number of electrons lost by Mg(s) is equal to the number of electrons gained by Ni2+(ag).
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The electrons that are gained by the \(Ni^{2+}\) ion is 2.0 moles of electrons.
What is the number of the electrons gained?We know that when there is a redox reaction, there would be the loss or gain of electrons in the process. The process is a simultaneous one so the electrons that are lost by one specie must as a matter of necessity be gained by another specie.
In this case, as we look at the reaction equation we can see that there are two electrons that have been lost by the magnesium atom and these two electrons would be gained by the Nickel II ion.
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Calculate the work (w) and ΔEo, in kJ, at 298 K and 1 atm pressure, for the combustion of one mole of C4H10 (g). First write and balance the equation. The products will be CO2 (g) and H2O (g)
The value of ΔHo for this reaction is -2658.3 kJ/mol
Answer:
Explanation:
2C₄H₁₀ + 13O₂ = 8 CO₂ + 10H₂O
Change in number of moles Δn = 18 - 15 = + 3 moles .
ΔHo = -2658.3 kJ/mol.
ΔHo = ΔEo+ Δn RT
Δn = 3
For one mole Δn = 1.5
ΔHo = ΔEo+ W
W = Δn RT
= 1.5 x 8.31 x 298
= 3714.5 J
= 3.7 kJ /mole
ΔHo = ΔEo+ W
ΔEo = ΔHo - W
= -2658.3 - 3.7 kJ
= - 2662 kJ .
(a) The work done for the combustion of 1 mole of methane is 3,714.5 J.
(b) The change in the energy of the given system is -3,991.2 kJ.
The balanced chemical reaction of the given compounds is written as follows;
\(2C_4H_{10} \ + \ 13O_2 \ -->\ 8CO_2 \ + \ 10H_2 O\)
The change in number of moles;
\(\Delta n = 18 - 15 = 3\)
The work done for the combustion of 1 mole of methane is calculated as follows;
\(W = \frac{\Delta n}{2} RT\\\\W = \frac{3}{2} \times 8.31 \times 298\\\\W = 3,714.6 \ J\)
The energy change is calculated as follows;
\(\Delta E_0 = \Delta H_o - W\\\\\Delta E_0 = (\frac{3 \ mole}{2} \times-2658.3 \ kJ/mol) - 3.715 \ kJ\\\\\Delta E_0 = -3,991.2 \ kJ\)
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The reactant concentration in a zero-order reaction was 8.00×10−2 M
after 140 s and 4.00×10−2 M after 400 s
. What is the rate constant for this reaction?
The rate constant for the reaction is either 7.14×10−3 s−1 or 2.50×10−3 s−1, depending on which rate was used to calculate it.
Determining the rate constantThe rate of the reaction is given by the equation:
Rate = -k[A]
where k is the rate constant and [A] is the concentration of the reactant.
Rate at t=140 s:
Rate = (8.00×10−2 M - 0 M) / (140 s - 0 s)
= 5.71×10−4 M/s
Rate at t=400 s:
Rate = (4.00×10−2 M - 0 M) / (400 s - 0 s)
= 1.00×10−4 M/s
Since this is a zero-order reaction, the rate of the reaction is constant, and we can use either rate to calculate the rate constant:
k = Rate / [A]
Using the rate at t=140 s:
k = 5.71×10−4 M/s / 8.00×10−2 M = 7.14×10−3 s−1
Using the rate at t=400 s:
k = 1.00×10−4 M/s / 4.00×10−2 M
= 2.50×10−3 s−1
The rate constant for the reaction is either 7.14×10−3 s−1 or 2.50×10−3 s−1.
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Any help?
The Kb for hydroxylamine, HONH2, is 1.1 x 10 -8
. What would be the pH of a solution
prepared by placing 1.34 g of HONH2 in 0.500 L of water?
Answer:
pH = 9.475
Explanation:
Hello there!
In this case, according to the basic ionization of the hydroxylamine:
\(HONH_2+H_2O\rightarrow HONH_3^++OH^-\)
The resulting equilibrium expression would be:
\(Kb=\frac{[HONH_3^+][OH^-]}{[HONH_2]} =1.1x10^{-8}\)
Thus, we first need to compute the initial concentration of this base by considering its molar mass (33.03 g/mol):
\([HONH_2]_0=\frac{1.34g/(33.03g/mol)}{0.500L} =0.0811M\)
Now, we introduce \(x\) as the reaction extent which provides the concentration of the hydroxyl ions to subsequently compute the pOH:
\(1.1x10^{-8}=\frac{x^2}{0.0811-x}\)
However, since Kb<<<<1, it is possible to solve for \(x\) by easily neglecting it on the bottom to obtain:
\(x=[OH^-]=\sqrt{1.1x10^{-8}*0.0811}= 2.99x10^{-5}\)
Thus, the pOH is:
\(pOH=-log(2.99x10^{-5})=4.525\)
And the pH:
\(pH=14-4.525\\\\pH=9.475\)
Regards!
PLEASE HELP...
Balance this nuclear reaction by supplying the missing nucleus. Replace each question mark with an appropriate integer or symbol.
Cf98249 + ? ⟶Db105260+410n
The balanced form of the nuclear equation is as follows; 249/98 Cf + 15/7 N⟶ 260/105 Db + 4(1/0) n.
What is a nuclear equation?A nuclear equation is process such as the fission of an atomic nucleus, or the fusion of one or more atomic nuclei and/or subatomic particles in which the number of protons and/or neutrons in a nucleus changes.
According to this question, Californium element is a reactant to produce dubnium and a neutron as products.
However, the law of conservation of mass must be fulfilled by ensuring the mass and atomic numbers of elements in reactant and product side are the same.
249/98 Cf + 15/7 N⟶ 260/105 Db + 4(1/0) n
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What are some potential real-world applications for renewable energy sources such as solar power and wind power?
The some of the potential in the real world applications for the renewable energy sources such as the solar power and the wind power are electricity generation, the water heating and cooling, and the transportation.
Renewable energy defined as the energy produced from the sources like the sun and the wind energy which are the naturally replenished and which do not run out.
The Renewable energy which can be used for the electricity generation, and the water heating and the cooling, and the transportation. The most sustainable sources of the energy are the renewable bioenergy. The Renewable sources of the, like the wind and the solar, it will emit the little to no the greenhouse gases.
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Chemistry problem. please help
Answer:
solid X contains only ionic bond, and solid Y contains only covalent bonds.
Explanation:
solid X contains only ionic bond, and solid Y contains only covalent bonds. Because ionic compounds they have high melting point compared to covalent compounds, ionic compound they are generally insoluble in non polar solvent such as toluene but soluble in polar solvent such as water, ionic compound they conduct electricity.
Drag each phrase to show weather it causes water pollution or is an effect of water pollution. (2 points)
Choices:
Algal blooms
Overgrazing
Use of chemical fertilizers to enhance production
High concentration of nitrogen in water
Algal blooms and high concentrations of nitrogen in water are effects of water pollution. Overgrazing and the use of chemical fertilizers cause water pollution.
Water pollutionAlgal blooms are an effect of water pollution. They occur when there is an excessive amount of nutrients, particularly nitrogen and phosphorus, in the water due to pollution. The overgrowth of algae depletes the oxygen levels in the water, which can harm fish and other aquatic animals.
Overgrazing can cause water pollution by increasing the sedimentation rate of waterways. This sedimentation can carry nutrients, bacteria, and other pollutants into the water, which can degrade water quality and cause harm to aquatic life.
The use of chemical fertilizers to enhance production is a cause of water pollution. When fertilizer is overused, it can leach into waterways and cause nutrient pollution, which can lead to algal blooms and other forms of water pollution.
High concentrations of nitrogen in water are often an effect of water pollution. This can be caused by the overuse of fertilizers or the discharge of untreated sewage into waterways. High nitrogen levels can cause algal blooms, which can lead to oxygen depletion and harm aquatic life.
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Answer:
Cause:
: : use of chemical fertilizers to enhance production
: : overgrazing
Effect:
: : high concentration of nitrogen in water
: : algal blooms
Hope this helps ;)
Balance the following equations by writing the coefficients in the space provided. Then classify each of the following reactions by writing the name of the type of reaction on the line. Choose from synthesis, decomposition, single replacement, double replacement, and combustion___FeCl3 + ___NaOH → ___Fe(OH)3 + ___NaCl _________________
To balance the equation we start by counting the number of atoms we have of each element on each side of the reaction.
Reagents side:
Fe = 1 atom
Cl= 3 atoms
Na=1 atom
O=1 atom
H= 1atom
Products side:
Fe = 1 atom
Cl= 1 atom
Na=1 atom
O= 3 atoms
H= 3 atoms
Let's start with chlorine, we have 3 chlorine atoms on the reactant side and 1 on the product side. So we will put the coefficient 3 in the NaCl molecule to balance the chlorine.
\(Fe_{}Cl_3+Na_{}OH\rightarrow Fe(OH)_3+3NaCl\)Now, we will have:
Reagents side:
Fe = 1 atom
Cl= 3 atoms
Na=1 atom
O=1 atom
H= 1atom
Products side:
Fe = 1 atom
Cl= 3 atom
Na= 3 atom
O= 3 atoms
H= 3 atoms
Now, we balance the Na, we have 1 atom of Na in the reactants and 3 in the products. We then put coefficient 3 in the NaOH molecule.
\(Fe_{}Cl_3+3Na_{}OH\rightarrow Fe(OH)_3+3NaCl\)We have now the equation balanced:
Reagents side:
Fe = 1 atom
Cl= 3 atoms
Na=3 atoms
O=3 atoms
H= 3 atoms
Products side:
Fe = 1 atom
Cl= 3 atom
Na= 3 atom
O= 3 atoms
H= 3 atoms
We have the same number of atoms of each element on both sides of the reaction.
Now, in the reaction we can notice that Cl and OH happen to substitute the place of the other, therefore, this reaction will be a double replacement reaction.
A balloon filled with helium gas occupies 2.50 L at 25°C and 1.00 atm. When released, it rises to an altitude where the temperature is 20°C and the pressure is only 0.50 atm.
Calculate the new volume of the balloon.
Answer:
4 L
Explanation:
using general gas equation formula (in blue pen in attached image),
P1 = 1 atm
V1 = 2.5 L
T1 = 25°C
P2 = 0.5 atm
V2 = x
T2 = 20°C
making V2 subject of the formula (in red pen in attached image),
V2 = 1*2.5*20/25*0.5
= 50/12.5
= 4 L
have a great day!!!
A heater in a classroom provides heat, but the temperature in the room stays the same why
A volume of 10.0 mL of 25 mg/L Mn2+ solution was diluted to make a solution with the final volume of 50.0 mL. Calculate the concentration (in mg/L) of the final solution
Taking into account the definition of dilution, the concentration of the final solution is 5 mg/L.
First of all, you have to know that dilution is the reduction in concentration of a chemical in a solution. The process consists of adding more solvent to the same amount of solute.
In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases.
A dilution is mathematically expressed as:
Ci×Vi = Cf×Vf
where
Ci: initial concentration Vi: initial volume Cf: final concentration Vf: final volumeIn this case, you know:
Ci= 25 mg/L Vi= 10 mL Cf= ? Vf= 50 mLReplacing in the definition of dilution:
25 mg/L × 10 mL= Cf × 50 mL
Solving:
Cf= (25 mg/L × 10 mL)÷ 50 mL
Cf= 5 mg/L
In summary, the concentration of the final solution is 5 mg/L.
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brainly.com/question/20113402?referrer=searchResults brainly.com/question/22762236?referrer=searchResults4.A 250 mL sample of HCl solution reacts with 2.5 g of Al according to the following reaction. Determine the concentrationof the HCI. Show your work for credit.6HCl(aq) + 2Al(s) -----> 2AICI, (aq) + 3H:(9)
In this question, we have the following reaction:
6 HCl + 2 Al -> 2 AlCl3 + 3 H2
We have:
250 mL of HCl
2.5 g of Al
And we want to find the molar concentration of HCl
One way of doing it is by finding the number of moles of HCl present in this solution, we can do that by using the number of moles of Al and after that, comparing the molar ratio of HCl and Al. To find the number of moles of Al, we will use its molar mass 27g/mol
27g = 1 mol
2.5g = x moles
x = 0.0926 moles of Al in 2.5 grams
Now by looking at the properly balanced reaction, we can see that the molar ratio between HCl and Al is 6:2, so if we have 0.0926 moles of Al, we will have:
6 HCl = 2 Al
x HCl = 0.0926 Al
x = 0.2778 moles of HCl
Now that we have the volume and the number of moles, we can find the molar concentration of HCl, using the Molarity formula:
M = number of moles/volume in liters
M = 0.2778/0.250
M = 1.11 is the molar concentration of HCl in this given solution