Answer:
Heat Energy needed (Q) = 68250 J
Energy lost (Q') = 10500 J
Explanation:
Applying,
Q = cm(t₂-t₁)............. Equation 1
Where Q = heat energy needed, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature.
From the question,
Given: m = 250 g = 0.25 kg, t₁ = 20.0°C, t₂ = 85.0°C
Constant: c = 4200 J/kg°C
Substitute these values into equation 1
Q = 0.25(4200)(85-20)
Q = 68250 J.
Similarly, heat lost
Q' = cm(t₁-t₂)................. Equation 2
Where Q = heat lost
Given: t₁ = 85°C, t₂ = 75°C
Substitute into equation 2
Q' = 4200(0.25)(85-75)
Q' = 10500 J
Which statement best describes wave-particle duality as it applies to electrons?
A. The electrons present in radio waves and microwaves act more like particles than waves.
B. Electrons are particles that emit waves of radiation when they move from higher energy levels to lower energy levels.
с.Electron clouds can be understood as clumps of particles held near one another by wave forces.
D.Electrons can be modeled as waves in some situations and as particles in other situations.
Answer:
D es pero que te ayude amigo
please i need help ……
Answer:
H2
Explanation:
(l) means liquid
(s) means solid
(g) means gaseous
I hope this helped [:
the rate of diffusion of gas having molecules mass 4 times that ouch4 is 50 cc.the rate of diffusion of mithane is??
Answer: The rate of diffusion of methane is 100 cc.
Explanation:
Graham's law states that the rate of diffusion of a gas is inversely proportional to the square root of the molar mass of the gas. The equation for this follows:
[tex]\text{Rate}=\frac{1}{\sqrt{M}}[/tex] .....(1)
where M is the molar mass of the gas
We are given:
[tex]Rate_{X}=50cc[/tex]
[tex]M_{X}=4\times M_{CH_4}[/tex]
Since the molar mass of methane = 16 g/mol
Using equation 1:
[tex]\frac{Rate_{CH_4}}{Rate_{X}}=\sqrt{\frac{M_X}{M_{CH_4}}}[/tex]
Putting values in above equation, we get:
[tex]\frac{Rate_{CH_4}}{50cc}=\sqrt{\frac{(4\times 16)}{16}}\\\\Rate_{CH_4}=50\times \sqrt{4}\\\\Rate_{CH_4}=50times 2=100cc[/tex]
Hence, the rate of diffusion of methane is 100 cc.
Which ionic equation describes a redox reaction? A. Ag(+) + Cl- = AgCl B. 2H(+) + CO3(2-) = CO2 + H2O C. H(+) + OH(-) = H2O D. Zn + Cu(2+) = Zn(2+) + Cu The marking scheme of the past paper this question is from says that the answer is D but how?
Answer: The correct option is D. [tex]Zn+Cu^{2+}\rightarrow Zn^{2+}+Cu[/tex]
Explanation:
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously. It is known as the reaction in which the exchange of electrons takes place.
The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when the oxidation number of a species increases.
A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when the oxidation number of a species decreases.
From the given ionic reactions:
[tex]Zn+Cu^{2+}\rightarrow Zn^{2+}+Cu[/tex]
On the reactant side:
Oxidation number of Zn = 0
Oxidation number of Cu = +2
On the product side:
Oxidation number of Cu = 0
Oxidation number of Zn = +2
As the oxidation number of Zn is increasing from 0 to +2. Thus, it is getting oxidized. Similarly, the oxidation number of Cu is decreasing from +2 to 0. Thus, it is getting reduced. Therefore, forming a redox couple
Hence, the correct option is D. [tex]Zn+Cu^{2+}\rightarrow Zn^{2+}+Cu[/tex]
State the method you will use to separate the following substances. (a) calcium carbonate from table salt (b) iodine from sodium chloride (c) table salt from seawater (d) sugar from sugar solution (e) pure water from sewage water (f) ethanol from beer (g) yellow dye from durian ice cream
Answer:
https://www.meritnation.com :)I HOPE IT'S HELP
Answer: There are many forms of table salt: coarse salt, refined salt, iodized salt. It is a crystalline solid, white to very pale pink or gray in color, obtained from seawater or salt deposits. Salt obtained from seawater has crystals that are smaller or larger than rock salt. In nature, table salt consists mainly of sodium chloride (NaCl), but also a few other minerals (trace minerals). Table salt obtained from rock salt may appear more gray because of traces of trace minerals. Table salt is necessary for the survival of all living organisms, including humans. Table salt is involved in regulating the body's water content (liquid balance).
Help, quick, pls
What is a displacement reaction?
[tex]\begin{aligned} -5x+4y &= 3\\\\ x&=2y-15 \end{aligned}[/tex]
What is the wavelength of light with 4.01 x 10^-19 J of energy? (The speed of light in a vacuum is 3.00 x 10^8 m/s, and Planck's constant is 6.626 x 10^-34 Jos.)
A. 1820 nm
B. 496 nm
C. 202 nm
D. 551 nm
Answer:
D
hope it helps:)))!!!!!!
The concept Planck's quantum theory of radiation is used here to determine the wavelength of the light. The wavelength of the light with 4.01 x 10⁻¹⁹ J of energy is 496 nm . The correct option is B.
What is Planck's quantum theory?According to Planck's quantum theory, different atoms and molecules can emit or absorb energy in discrete amount only. The smallest amount of energy which can be emitted or absorbed in the form of electromagnetic radiation is called quantum.
The energy of the radiation absorbed or emitted is directly proportional to the frequency of the radiation. It is given by the equation:
E = hν
ν = E / h
4.01 x 10⁻¹⁹ J / 6.626 x 10⁻³⁴ = 6.05 × 10¹⁴ Hz
We have,
ν = c / λ
λ = c / ν
3.00 x 10⁸ / 6.05 × 10¹⁴ = 4.958 × 10⁻⁷ m
1 nm = 1 × 10⁻⁹ m
4.958 × 10⁻⁷ m = 495.8 nm = 496 nm
Thus the correct option is B.
To know more about wavelength, visit;
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Select the correct answer.
Which atom or lon is the largest?
Answer:urenium
Explanation: because his atomic number is 235
Answer:
We know when the no of protons (+ charge) is greater than the no of electrons (- charge), the nucleus pulls the electrons with greater force, hence making the size smaller. Clearly, the cations are smaller than the atoms, this largest atom/ion will be Ca.
K has 19 protons, 19 electrons
K+ has 19 protons, 18 electrons
Ca has 20 protons, 20 electrons
Ca2+ has 20 protons, 18 electrons
Li has 3 protons, 3 electrons
Clearly, the cations are smaller than the atoms, this largest atom/ion will be Ca.
Explanation:
Jonathan conducts an experiment to determine what solutes readily dissolve in water. He places 3 tablespoons of potting soil into one cup of water. He records his observations in 15-minute increments. After a half hour, he notices that some of the soil particles have separated and sank to the bottom. O 15 minutes 30 minutes Which term best describes the combination of soil and water?
A.Mixture
B. A solution
C. an alloy
D. an emulsion
Answer:
A. Mixture
Explanation:
For the reaction C + 2H2 → CH4, how many moles of hydrogen are needed to make 192.3 grams of methane, CH4?
Answer:
24
Explanation:
Calculate the total amount of energy required in calories to convert 50.0 g of ice at 0.00 degrees Celsius to steam at 100. degrees Celsius.
Specific heat capacity of water is 1.00 cal/g OC
Hfusion = 80 cal/g OC and Hvap = 540 cal/g OC
Write the complete equation you will use.
Substitute the values in the equation in step 1.
Report the math answer with 3 sig figs and the correct unit.
Answer: The amount of heat absorbed is [tex]36.0\times 10^3Cal[/tex]
Explanation:
Few processes involved are:
(1): [tex]H_2O (s) (0^oC, 273K) \rightleftharpoons H_2O(l) (0^oC,273K)[/tex]
(2): [tex]H_2O (l) (0^oC, 273K) \rightleftharpoons H_2O(l) (100^oC,373K)[/tex]
(3): [tex]H_2O (l) (100^oC, 373K) \rightleftharpoons H_2O(g) (100^oC,373K)[/tex]
Calculating the heat absorbed for the process having same temperature:
[tex]q=m\times \Delta H_{(f , v)}[/tex] ......(i)
where,
q is the amount of heat absorbed, m is the mass of sample and is the enthalpy of fusion or vaporization
Calculating the heat released for the process having different temperature:
[tex]q=m\times C_{s,l}\times (T_2-T_1)[/tex] ......(ii)
where,
[tex]C_{s,l}[/tex] = specific heat of solid or liquid
[tex]T_2\text{ and }T_1[/tex] are final and initial temperatures respectively
For process 1:We are given:
[tex]m=50.0g\\\Delta H_{fusion}=80Cal/g[/tex]
Putting values in equation (i), we get:
[tex]q_1=50.0g\times 80Cal/g\\\\q_1=4000Cal[/tex]
For process 2:We are given:
[tex]m=50.0g\\C=1.00Cal/g^oC\\T_2=100^oC\\T_1=0^oC[/tex]
Putting values in equation (i), we get:
[tex]q_2=50g\times 1Cal/g^oC\times (100-0)\\\\q_2=5000Cal[/tex]
For process 3:We are given:
[tex]m=50.0g\\\Delta H_{vap}=540Cal/g[/tex]
Putting values in equation (i), we get:
[tex]q_3=50.0g\times 540J/g\\\\q_3=27000Cal[/tex]
Calculating the total amount of heat released:
[tex]Q=q_1+q_2+q_3[/tex]
[tex]Q=[(4000)+(5000)+(27000)]Cal=36000Cal=36.0\times 10^3Cal[/tex]
Hence, the amount of heat absorbed is [tex]36.0\times 10^3Cal[/tex]
The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change
that must happen at the molecular level?
The molecules move more quickly and their average kinetic energy increases
The molecules move more bowly and their average kinetic energy decreases
The molecules move more quickly and their average kinetic energy decreases
The molecules move more slowly and their average kinetic energy increases.
Answer:
The molecules move slower than the temp of 50°c and their average kinetic energy decreases.
Explanation:
kinetic energy cannot increase as temperature is reduced. molecules will still move with reduced motion.
18- The number of orbitals in each sublevel are:
A:-s:2, p:3, d:10, and f:14
B:-s:2, p:6, d:10, and f:14
C:-s:1, p:3, d:5, and f:7
D:-s:1, p:2, d:3, and f: 4
s2,p6,d10,f14
S contains 2 orbitals
P contains 6 orbitals
D contains 10 orbitals
F contains 14 orbitals
Read the following reactions. Reaction 1: CaO(s) + CO2(g) → CaCO3(s) Reaction 2: H2O(g) → H2O(l) Which reaction leads to an increase in entropy? Only Reaction 1 Only Reaction 2 Both Reaction 1 and 2 Neither Reaction 1 nor 2
Answer: In the given reactions neither reaction 1 nor 2 reaction leads to an increase in entropy.
Explanation:
The degree of randomness present in the molecules of a substance is called entropy.
In gases, molecules are held by weak forces due to which they move apart from each other. Hence, they have high entropy.
In liquids, molecules are a little close to each other so they have less entropy than gases.
In solids, molecules are tightly held together so they have least or negligible entropy.
As reaction 1 is [tex]CaO(s) + CO_{2}(g) \rightarrow CaCO_{3}(s)[/tex] and it shows that product is in solid state. Therefore, entropy is decreasing.
As reaction 2 is [tex]H_{2}O(g) \rightarrow H_{2}O(l)[/tex] and it shows that gas is converted into liquid. Therefore, entropy is also decreasing here.
Thus, we can conclude that in the given reactions neither reaction 1 nor 2 reaction leads to an increase in entropy.
Answer: Neither Reaction 1 nor 2
Explanation:
Una muestra de 2,5000 (g) de piedra caliza, se disuelve y se precipita el Calcio como oxalato de Calcio (CaC2O4), este precipitado se calcina transformándose en Carbonato de Calcio (CaCO3). El peso de este compuesto es de 1,2093 (g). Calcular el % de Calcio en la muestra
Answer:
[tex]\%Ca=19.378\%[/tex]
Explanation:
¡Hola!
En este caso, basado en la información dada, es posible conocer la masa de calcio en carbonato de calcio, que de hecho es la misma en la muestra, al utilizar el siguiente esquema de cálculo:
[tex]m_{Ca}=1,2093gCaCO_3*\frac{1molCaCO_3}{100.1gCaCO_3}*\frac{1molCa}{1molCaCO_3}*\frac{40.1gCa}{1molCa}\\\\m_{Ca}=0.48444gCa[/tex]
Finalmente, calculamos el porcentaje requerido como sigue:
[tex]\% Ca=\frac{0.48444g}{2.5000g} *100\%\\\\\%Ca=19.378\%[/tex]
¡Saludos!
What point A on the phase diagram called?
liquid
(374°C/218 atm)
A
solid
pressure (atm)
gas
temperature (°C)
OA.
the melting point
OB.
the boiling point
Ос.
the freezing point
OD
the critical point
OE.
the triple point
Answer:
D) the critical point
Explanation:
Point A is the critical point in phase diagram. This is the highest temperature and pressure at which a pure material can exist in vapor/liquid equilibrium. Pretty cool!
Which of the following would be expected to have the highest viscosity? CH3CH2OH, HOCH2OH, CH3CH2CH3
О НОСН2ОН
O They are all the same.
О СН3СН2ОН
O CH3CH2CH3
Answer: Out of the given options [tex]HOCH_{2}OH[/tex] is expected to have the highest viscosity.
Explanation:
The resistance occurred in the flow of a liquid substance is called viscosity.
More stronger is the intermolecular forces present in a substance more will be its resistance in its flow. Hence, more will be its viscosity.
For example, [tex]HOCH_{2}OH[/tex] has strong intermolecular hydrogen bonding than the one's present in [tex]CH_{3}CH_{2}OH[/tex] and [tex]CH_{3}CH_{2}CH_{3}[/tex]. This is because two-OH groups are present over here.
Thus, we can conclude that out of the given options [tex]HOCH_{2}OH[/tex] is expected to have the highest viscosity.
Are your knees the elbows of your legs or are your elbows the knees of your
arms?
A.knees are elbows of your legs
B.elbows are knees of your arms
C.both
Answer:
Both :)
Explanation:
Knees and elbows are the types of joints that are present to move the parts of the body attached to it. The knees are the elbows, and the elbows are the knees.
What are joints?The joints knees and elbows work like the door and allow the movement of the attached body parts in back and forth directions.
The elbow of the arm region and the knee of the leg region have similar functions and are homologous in the function that moves the leg of the lower region and the arm of the upper region.
Therefore, option c. both is the correct option.
Learn more about knee and elbow here:
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⬆️= you need to come up with investigation question, to help inform your decision.
Think about how land, water, and air absorb and release
Thermal energy and then formulate your hypothesis
I need some Investigation questions about how land, water, and air absorb and release
Thermal energy :,)
Subject: science
Answer:
1. how dense is the land and what matreal
2. what is the humidity and is there any wind
3.how pure is the water if it full of minarils
Explanation:
There are on average 43 g of sugar and 355 mL can of soda please calculate the molarity of sugar in the can of soda the molar mass of sugar is 342.2 g/mol
Explanation:
Given :
Amount of solute - sucrose (C12H22O11) = 41 g
Amount of solvent -soda = 355-mL
Molarity of the solution with respect to sucrose= ?
Molarity(M) is a unit of concentration measuring the number of moles of a solute per liter of solution. The SI unit of molarity is mol/L.
Formula to find the molarity of solution :
Molarity =
Amount of solvent is given in mL, let’s convert to L :
1 L = 1000 mL
Therefore, 355 mL in L will be :
= 0.355 L
We have the amount of solute in g, let’s calculate the number of moles first :
Number of moles (n) =
Molar mass of C12H22O11 = 342.29 g/mol.
Therefore, n =
= 0.119 moles.
If one of the reactants in a reaction us Na2O, what is known about the products?
Ok here's the deal
the answer is A: The products will contain exactly 2 Na atoms and 1 O atom.
Explanation:
thank me later space-ex kids
why elements with more than 20 protons always have a more neutrons than protons?
Answer:
Elements that have atomic numbers from 20 to 83 are heavy elements, therefore the ratio is different. The ratio is 1.5:1, the reason for this difference is because of the repulsive force between protons: the stronger the repulsion force, the more neutrons are needed to stabilize the nuclei.
H2SO4 +HI → __ H2S+12 +H2O balance the equation
Answer:
H2SO4 + 8HI → H2S + 4I2 + 4H2O
How many mL of 0.013 M potassium hydroxide are required to reach the equivalence point in the titration of 75 mL 0.166 M hydrocyanic acid?
Answer:
957.7mL
Explanation:
Using the formula below;
CaVa = CbVb
Where;
Ca = concentration of acid (M)
Va = volume of acid (mL)
Cb = concentration of base (M)
Vb = volume of base (mL)
According to the information provided in this question:
Ca = 0.166 M
Cb = 0.013 M
Va = 75mL
Vb = ?
Using CaVa = CbVb
0.166 × 75 = 0.013 × Vb
12.45 = 0.013Vb
Vb =12.45/0.013
Vb = 957.7mL
give few property of PET
Answer:
Transparency to visible light and microwaves. Very good resistance to ageing, wear and heat. Lightweight, impact and shatter resistant. Good gas and moisture barrier properties
Explanation:
Answer:
Your Welcome! :)
Explanation:
What are the Characteristics of Polyethylene terephthalate (PETE or PET)?
Chemical Resistance: PET does not react with water or food which is one of the reasons it is used for consumable packaging.
Strength to Weight Ratio: PET is very strong for its lightweight.
Shatterproof: PET will not break or fracture.
how many different sublevels are in the second energy level?
2
1
4
3
Answer:
The answer is 2
Explanation:
There are two energy sublevels in the second principal energy level. These two energy sublevels are 2s and 2p. The energy distribution in an atom is divided into a number of principal energy levels, and the principal energy levels are again divided into four basic energy sublevels.
can someone please explain core and valence electrons in periods for me please
Answer:
The electrons of an atom are typically divided into two categories: valence and core electrons. Valence electrons occupy the outermost shell or highest energy level of an atom while core electrons are those occupying the innermost shell or lowest energy levels
Explanation:
i hope u get it :))
sulfur and oxygen can react to form both sulfur dioxide and sulfur trioxide in sulfur dioxide there are 32.06 grams of sulfur and 32 grams of oxygen in sulfur dioxide there are 32.06 grams of sulfur are combined with 48 grams of oxygen
a. what is the ratio of the weights of oxygen that combine with 32.06 g of sulfur ?
b. How do these data illustrate the law of multiple proportions?
Answer:
Explanation:
In sulfur dioxide there are 32.06 grams of sulfur and 32 grams of oxygen .
In sulfur trioxide there are 32.06 grams of sulfur are combined with 48 grams of oxygen.
The ratio of oxygen which reacts with 32.06 gram of sulfur is 32: 48 .
This ratio is equal to 2 : 3.
This is in accordance with law of multiple proportion because , the ratio of mass of oxygen which reacts with constant mass of sulfur is integral ratio . Hence they are in accordance with law of multiple proportions.
Answer:
sulfur and oxygen can react to form both sulfur dioxide and sulfur trioxide in sulfur dioxide there are 32.06 grams of sulfur and 32 grams of oxygen in sulfur dioxide there are 32.06 grams of sulfur are combined with 48 grams of oxygen
a. what is the ratio of the weights of oxygen that combine with 32.06 g of sulfur?
b. How do these data illustrate the law of multiple proportions?
Explanation:
In sulfur dioxide ([tex]SO_2[/tex])
32.06 g of sulfur reacts with 32.0 g of oxygen.
In sulfur trioxide ([tex](SO_3)[/tex] 32.0 g of sulfur reacts with 48.0 g of oxygen.
So, both th ecom[pounds are made from sulfur and oxygen,
But the amount of oxygen reacts with fixed amount of sulfur that is 32.06 g and it is in proportions that is:
32.0 g : 48.0 g
=2:3.
Hence, the ratio of oxygen combines with sulfur is in the ratio of 2:3.
b.
This data illustrates the law of multiple proportions.
Because the oxygen which is combining with fixed amount of sulfur is in proportions.
How does light demonstrate quantization?
A. The velocity of a light wave has a direction as well as speed.
B. The wavelength of light increases as the frequency decreases.
C. The frequency of light increases as energy increases.
D. The energy in light waves comes in units called photons.
Answer:
D. The energy in light waves comes in units called photons.
Explanation:
its known as quatum theory
PLZ HELP!!! QUESTIONS ARE BELOW!!! :D PLZ COMPLETELY ANSWER THE QUESTIONS WITH A GOOD ANSWER :)
Answer: sorry its lagging i hope this help fore 18.. =D
Explanation:
n,s is repeating the cycle of the inside
Answer/Explanation:
18, a,
I believe the n, and s represents North, South, or just the way the arrows are rotating repeatedly.
18, b,
The phenomenon re-occurring shows the alignment of magnetic dipoles with in a magnet, like inside. The arrows show a direction in the line with an external magnetic field in a way that it can produce its own magnetic fields that seem to travel from North to the South.
18, c,
Incorrect. Refrigerator magnets have multiple layers of magnification, they use opposite polarities to stay this way. If he puts the magnet sideways it may stick to the fridge
~ LadyBrain
