Answer:
[tex]\Delta H=1149.5J[/tex]
Explanation:
Hello!
In this case, since the calorimeter contains a solution for which the specific heat is 4.18 J/g°C, which is equal to that of the water, we can also notice that the density is 1.00 g/mL and therefore the present mass is 250 g. In such a way, we compute the enthalpy change as shown below:
[tex]\Delta H=mC\Delta T[/tex]
Thus, by plugging in the mass, specific heat and temperature change, we obtain:
[tex]\Delta H=250g*4.18\frac{J}{g\°C}(26.1\°C-25.0\°C)\\\\\Delta H=1149.5J[/tex]
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Every magnet must have what at its ends?
Answer:
A) a north pole and a south pole
Explanation:
As, a magnet will have a north pole in one of its end and a south pole in the other
Please help with chemistry homework (I’ll mark brainliest!)
Answer:
You answer is correct
Electrons have a negative charge. The charge on the proton and electron are exactly the same size but opposite. Neutrons have no charge.
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Find the Molarity of 6.25 grams of barium nitrate dissolved in 250 mL solution.
Answer:
0.096 M
General Formulas and Concepts:
Chemistry - Solutions
Writing compounds with polyatomic ionsMolarity = moles of solute / liters of solutionExplanation:
Step 1: Define
6.25 g Ba(NO₃)₂
250 mL
Step 2: Define conversions
1000 mL = 1 L
Molar Mass of Ba - 137.33 g/mol
Molar Mass of N - 14.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Ba(NO₃)₂ - 137.33 + 2(14.01) + 6(16.00) = 261.35 g/mol
Step 3: Convert
[tex]250 \ mL(\frac{1 \ L}{1000 \ mL} )[/tex] = 0.25 L
[tex]6.25 \ g \ Ba(NO_3)_2(\frac{1 \ mol \ Ba(NO_3)_2}{261.35 \ g \ Ba(NO_3)_2} )[/tex] = 0.023914 mol Ba(NO₃)₂
Step 4: Find Molarity
M = 0.023914 mol Ba(NO₃)₂ / 0.25 L
M = 0.095657
Step 5: Check
We are given 2 sig figs as our smallest. Follow sig fig rules.
0.095657 M ≈ 0.096 M
Select the correct answer. How can technology negatively impact a guest’s perception of a restaurant? A. The POS system helps the server change a meal quickly when the guest changes their mind. B. It is easy to pay using the kiosks at the table. C. A Yelp search of the restaurant shows only poor, one-star reviews. D. The restaurant offers 10 percent off when returning for the third time.
Answer:
C.
Explanation:
Answer:
C
Explanation:
Why does a rocket accelerate when launched into Earth's orbit?
Answer:
Earth's gravity is still pulling down on the rocket. When a rocket burns propellants and pushes out exhaust, that creates an upward force called thrust. To launch, the rocket needs enough propellants so that the thrust pushing the rocket up is greater than the force of gravity pulling the rocket down.
help asap ..
using the stock name method when naming a translation metal ion that can have more than one common ionic charge, the numerical value of the charge is indicated by a ____ .
a: arabic number following the name .
b: superscript after the name .
c: roman numeral following the name .
d: prefix .
What is the density of an aqueous solution that is 50.0% KOH by mass and has a KOH concentration of 13.39 M?
Answer:
Density = 1.56 g/mL
Explanation:
We have two sort of concentrations in here, so let's combine them.
% by mass means grams of solute in 100 g of solution
M means, moles of solute in 1L of solution.
We know that our solute is KOH (Molar mass = 56.1 g/mol)
We convert the moles of solute to grams:
56.1 g/mol . 13.9 moles = 779.79 g
Now, we know that 50 g of solute are in 100 g of solution
Then, 779.79 g of solute will be contained in (100 . 779.79)/50 = 1559.58 g of solution
Density = mass / volume
1559.58 g of solution / 1000 mL of solution = 1.56 g/mL
The half-life of protactinium-217 is 4.9 x 10-3s. How much of a 3.50 mg sample of 21791 Pa will remain after 1.00 second?
Answer:
.
Explanation:
Which type of wavelength in UV/V spectroscopy is absorbed by easily excited
electrons?
A. Shorter wavelengths
B. All ultraviolet wavelengths
C. Longer wavelengths
D. No ultraviolet or visible wavelengths
Answer:
Longer wavelengths
Explanation:
The type of wavelength in UV/V spectroscopy is absorbed by easily excited electrons will be longer wavelengths.
What is wavelength?The distance a wave-particle travels after completing one oscillation would be its wavelength.
What is electrons?The electric charge of the electron, a subatomic particle, would be a negative elementary charge.
Between around 200 nm (only in near-ultraviolet ) and 800 nm, and absorption spectrometer operates (near infra-red). In that location, only a small fraction of the potential electron jumps can absorb light.
To know more about wavelength
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What do these two changes have in common? rain forming in a cloud water freezing into ice
Answer:
They're both examples of matter changing states.
Explanation:
Clouds = vapor, then forming rain = liquid
water = liquid freezing into ice = solid
An experiment requires that enough C3H8O be used to yield of oxygen .
How much C3H8O must be weighed out?
Answer: So if you had 570 cm of ribbon, then 570%2F8.5=67.05 which means that about 67 students can do the experiment (round down to the nearest whole number).
Explanation: If you had 8.5 cm of ribbon, then only 8.5%2F8.5=1 student can do the experiment. If you had 17 cm of ribbon, then 17%2F8.5=2 students can do the experiment.
As you move from left to right across the periodic table, electronegativity
Answer:
Electronegativity increases as you move across the periodic table from left to right.
Explanation:
Answer:
increases
Explanation:
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Answer:
A. Metal mixture is impure
_____ Al(NO3)3 + _____ (NH4)3PO4 → _____AlPO4 + _____ NH4NO3
Answer:
1 Al(NO3)3 + 1 (NH4)3PO4 → 1 AlPO4 + 3 NH4NO3
Explanation:
To balance Al(NO3)3 + (NH4)3PO4 → AlPO4 + NH4NO3 you'll need to be sure to count all of the atoms on each side of the chemical equation. Once you know how many of each type of atom you can only change the coefficients (the numbers in front of atoms or compounds) to balance the equation.
Important tips for balancing chemical equations:
Only change the numbers in front of compounds (the coefficients). Never change the numbers after atoms (the subscripts). The number of each atom on both sides of the equation must be the same for the equation to be balanced.B. Lex Luthor has a piece of kryptonite that measures W=3.0 cm by L=6.0 cm by
H=4.0 cm has a mass of 80.0 grams. What is the density of the kryptonite?
Would the piece of that float in water? Why?
(volume = L x W x H) (water density = 1g/cm3)
Answer:
1.11g/cm³
It will sink
Explanation:
Given parameters:
Dimension of the kryptonite:
W = 3cm
L = 6.0cm
H = 4.0cm
Mass = 80g
Unknown:
Density of the kryptonite = ?
Solution:
The density of a substance is its mass per unit volume;
Density = [tex]\frac{mass}{volume}[/tex]
Now let us find the volume;
Volume = L x W x H = 3 x 6 x 4 = 72cm³
So;
Density = [tex]\frac{80}{72}[/tex] = 1.11g/cm³
The substance will not float in water because its density is greater than that of water. It will sink in water.
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Answer:
D because excited electrons fall back.....
balance NO + 02 -- NO2
Answer:
NO + O2 -> NO2
it is balanced
What do you think the study of chemistry might be about? I need a sentence, thanks everyone for your help
Answer:
The study of chemistry is about the learning of chemist arts
Much like a battery, wood contains stored energy. What energy transformations occur when wood is burned?
Answer:
Chemical
Explanation:
What state of matter can be compressed?
A. gases
B. solids, liquids, and gases
C. liquids
D. solids
Answer:
Liquids, They are the only one that can change shape to fit the container
Answer:
option A is correct.
Explanation:
The atoms and molecules in gases are much more spread out than in solids or liquids. They vibrate and move freely at high speeds. A gas will fill any container, but if the container is not sealed, the gas will escape. Gas can be compressed much more easily than a liquid or solid.
What is the density of a lego block that has 4 cm length, 2 cm width, 4.5 cm height, Mass 18 g.
Answer:
density is [tex]\frac{mass}{volume}[/tex]
Explanation:
the volume of the block is 4 x 2 x 4.5 and that equals 36. Divide the mass by the volume and you get [tex]\frac{18}{36}[/tex] which is equal to 2 g per cubic centimeters
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Which of the following have the greasiest ionization energy Bi, As, K or Ga?
Answer the questions below:
1.Give an example of something that has matter.
2.Give an example of something that doesn't have matter.
3.What is the difference between an chemical change and a physical change?
4.What 2 main kind of changes can you observe involve chemical reactions?
5.What is a precipitate?
6.What is the difference between an endothermic reaction and an exothermic reaction?
Answer:
1. some thing that has matter is an apple, a person,a table. things that does 2.not Light.,Sound.,Heat.Energy.Gravity.Time.A Rainbow.Love.
3. Physical changes only change the appearance of a substance, not its chemical composition. Chemical changes cause a substance to change into an entirely substance with a new chemical formula. Chemical changes are also known as chemical reactions.
4.A chemical reaction is usually accompanied by easily observed physical effects, such as the emission of heat and light, the formation of a precipitate, the evolution of gas, or a color change. Absolute confirmation of a chemical change can only be validated by chemical analysis of the products!
5.Precipitate: In chemistry, a solid formed by a change in a solution, often due to a chemical reaction or change in temperature that decreases solubility of a solid. In meteorology a precipitate is liquid or solid water (rain, snow, etc.) falling from the sky.
6.n simple terms, the endothermic reactions absorb energy from the surrounding that is in the form of heat. On the other hand, an exothermic reaction releases energy into the surrounding of the system.
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Explanation:
Estimate ΔG°rxn for the following reaction at 775 K. 2Hg(g) + O2(g) → 2HgO(s) ΔH°= -304.2 kJ; ΔS° = -414.2 J/K
Answer:
[tex]\Delta G^0_{rxn}=16.81kJ[/tex]
Explanation:
Hello!
In this case, since the Gibbs free energy of any process is related with the enthalpy change, temperature and entropy change as shown below:
[tex]\Delta G^0=\Delta H^0-T\Delta S^0[/tex]
For a chemical reaction it is simply modified to:
[tex]\Delta G^0_{rxn}=\Delta H^0_{rxn}-T\Delta S^0_{rxn}[/tex]
Thus, since the enthalpy of reaction is given as -304.2 kJ and the entropy as -414.2 J/K (-0.4142 kJ/K), at 775 K the Gibbs free energy of reaction turns out:
[tex]\Delta G^0_{rxn}=-304kJ-775K*(-0.4142\frac{kJ}{K} )\\\\\Delta G^0_{rxn}=16.81kJ[/tex]
Whose result means this is a nonspontaneous reaction.
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What is the name of the waxy coating that keeps plants from drying out? chloroplast cuticle phloem xylem
Answer:
cuticle
Explanation:
Hope this help :)
Answer:
B(cuticle)
Explanation:
The mercury level in the open arm of an open-end manometer is 106 mm above the level in the arm connected to a tank of gas. If the barometric pressure is 0.958 atm, what is the pressure (in torr) of the gas in the tank?
Answer:
[tex]833.72\ \text{torr}[/tex]
Explanation:
[tex]P_g[/tex] = Pressure of gas = [tex]106\ \text{mmHg}[/tex]
[tex]P_a[/tex] = Atmospheric pressure = 0.958 atm
Absolute pressure is given by
[tex]P=P_g+P_a[/tex]
[tex]\Rightarrow P=\dfrac{106}{760}+0.958[/tex]
[tex]\Rightarrow P=1.097\ \text{atm}=1.097\times 760=833.72\ \text{torr}[/tex]
The pressure of the gas in the tank is [tex]833.72\ \text{torr}[/tex]
Which of the following statements is NOT correct?
Florida’s Everglades are low-lying wetlands in South Florida.
Florida’s lakes were formed by melting glaciers 100,000 years ago.
Florida’s coastline consists mainly of dunes, marshes, and swamps.
Florida’s sinkholes are a result of chemical weathering processes from rainwater and groundwater.
Answer:
I guess number three (3) Is wrong
Answer: taking thisin advanced middle school math doubt thats college
Explanation: has to be b or c, asked my teacher honestly everybody on here said b but 1 person said 3 which is partially incorrect but uh
What is the molarity of a solution prepared by dissolving 2.143E 1 grams of NaCl in water to make a 1.36E 2 mL solution
Answer:
b
Explanation:
causes onj the scale of 2 3 4 it equals s
What is ΔrH° for the following phase change? LiCl(s) → LiCl(l)
LiCl(s)
-408.27 ΔH°f (kJ/mol-rxn)
LiCl(l)
-390.76 ΔH°f (kJ/mol-rxn)
Answer:
[tex]\Delta _rH=17.51\frac{kJ}{mol}[/tex]
Explanation:
Hello!
In this case, since the enthalpy change for any process is computed by subtracting the enthalpy of the final state and the enthalpy of the initial state, for the given phase change, we subtract the enthalpy of the liquid (final state) and the enthalpy of the solid (initial state) considering this a melting process:
[tex]\Delta _rH=-390.76\frac{kJ}{mol} -(-408.27\frac{kJ}{mol} )\\\\\Delta _rH=17.51\frac{kJ}{mol}[/tex]
Which makes sense because this process absorbs energy.
Best regards!
The enthalpy change for the sublimation of LiCl(s) → LiCl(l) is 17.51 kJ/mol.
The enthalpy change for the phase change is given by;
ΔH°fproducts - ΔH°freactants.
From the available information in the question;
ΔH°fLiCl(s) = -408.27 kJ/mol
ΔH°fLiCl(l) = -390.76 kJ/mol
Hence;
ΔH°reaction = (-390.76 kJ/mol) - (-408.27 kJ/mol)
ΔH°reaction = 17.51 kJ/mol
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If 13.50 grams of hydrochloric acid (HCl) are reacted with excess calcium carbonate, how many grams of water are produced?
Answer:
3.3g
Explanation:
Given parameters:
Mass of HCl = 13.5g
Unknown:
Mass of water produced = ?
Solution:
The reaction equation is shown below;
2HCl + CaCO₃ → CaCl₂ + CO₂ + H₂O
To solve this problem, let us find the number of moles of the given specie first then we can use that to find the mass of the unknown water.
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of HCl = 1 + 35.5 = 36.5g/mol
Number of moles of HCl = [tex]\frac{13.5}{36.5}[/tex] = 0.37mol
From the balanced chemical reaction;
2 mole of HCl will produce 1 mole of H₂O
0.37mole of HCl will produce [tex]\frac{0.37}{2}[/tex] = 0.19mole of H₂O
So to find the mass of H₂O;
Mass = Number of moles x molar mass
Molar mass of H₂O = 2(1) + 16 = 18g/mol
Mass of H₂O = 0.19 x 18 =3.3g
