Answer:
Option A is correct.
Option D is correct.
E is the correct answer
Explanation:
This a theoretical calorimetry problem that can be solved by thermodynamic concepts.
Our system is the unknown solid. If the temperature of water has increased, we can think, that the heat from the metal was absorbed by water, which is our surrounding. If in the analysis of the situation we use a calorimeter, knowing that it is an isolated system, which does not allow the entry or exit of heat, we can conclude that the heat released is equal to the heat absorbed.
In conclusion, the thermodynamic system is constituted by the chemical reaction. In this case, the surrounding is made up of water and the calorimeter itself.
If the reaction is exothermic, the heat released by the reaction will be absorbed by the surrounding . Then, the final temperature will be higher than the initial temperature. If the reaction is endothermic, the heat absorbed by the reaction will be released by the environment. So, the final temperature will be lower than the initial temperature.A speed boat, at full throttle, can go 65.0 miles in 1.5 hours. What is the average speed of the boat?
The average speed = 43.33 miles per hours(mph)
Further explanationGiven
distance = 65 miles
time = 1.5 hours
Required
The average speed
Solution
The average speed : distance traveled divided by time taken or total distance divided by total elapsed time
Can be formulated :
avg speed = distance : time
avg speed = d : t
Input the value :
avg speed = 65 miles : 1,5 hours
avg speed = 43.33 miles per hours(mph)
A sample consisting of 65.0 g of xenon is confined in a container at 2.00 atm and 298 K and then allowed to expand adiabatically (a) reversibly to 1.00 atm, (b) against a constant pressure of 1.00 atm. Calculate the final temperature and the expansion work at each case. Use the fact that xenon is a monoatomic gas.
Answer:
[a]. - 445.45J,
[b]. - 367.92 J
Explanation:
The following parameters are given in the question above. These information are used in solving this problem.
The mass of Xenon = 65.0 g of xenon, pressure = 2.00 atm, temperature = 298 K.
The number of moles of xenon = mass/ molar mass = 65g/ 131.293= 0.495.
The cp= 3/2 R, cp =3/2R + R = 5/2 R.
j = cp/cv = 3/2.
[a]. The final temperature,T2 = (2)^-2/3 × (298)^5/3 = T2^5/3.
Final temperature,T2 = 225.84K.
Expansion work = nCv [ T₂ - T₁] = 0.495 × 3/2 × 8.314 × [ 225.84 - 298] = - 445.45J.
(b). The final temperature can be Determine as;
3/2( T2 - 298k) = - 1 (T2 /1 - 298/2).
3/2(T2 - 298) = - T2 + 149K.
3T2 - 894 = - 2T2 +298K.
T2 = 238.4 K.
Workdone= nCv (T2 - T1) = 0.495 × 3/2 × 8.314 (238.4 - 298) = - 367.92 J.
In which state of matter are the particles at rest (not moving at all)?
none of these
solid
liquid
gas
Answer:
Solids for sure
particles of solid cant flow.
Answer:
B)Solids
Solids have tightly packed particles unlike liquids and gases whose particles can move freely but rate of movement is highest in gas while compared to water
What is the energy of an electron in the third energy level of hydrogen?
Answer:
Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy.
...
Energy Levels of Electrons.
Energy Level Energy
1 -13.6 eV
2 -3.4 eV
3 -1.51 eV
4 -.85 eV
After adding 20.0 mL of 5% NaOH solution into the remaining organic layer, followed by mixing and venting, the solution separated into two distinct layers. Match the following:
1. The top layer was the ______________ layer.
2. 9-fluorenone was most soluble in the ____________ layer.
3. Deprotonated chloroanilic acid was most soluble in the _____________ layer.
4. The bottom layer was the __________________ layer.
5. The organic layer was a ________________ colored solution.
6. The aqueous layer turned into a _____________ colored solution.
a. organic
b. aqueous
c. yellow
d. pink
Answer:
Explanation:
The objective of this experiment is to match the expected result with each of the propositions given after the experiment had been carried out.
1. The top layer was the organic layer. This is because all the organic compounds have lesser density than water except chloroform that will be formed when NaOH is added.
2. 9-fluorenone was most soluble in the organic layer. This is so as a result of its non-polar carbon structure.
3. Deprotonated chloroanilic acid was most soluble in the aqueous layer as a result of the formation of an electrovalent bond with water.
4. The bottom layer was the aqueous layer as a result of the huge amount of water density.
5. The organic layer was a yellow colored solution.
6. The aqueous layer turned into a pink colored solution.
How many molecules in 4.10 mol H2O?
6.02×10^23
1.4×10^23
2.47×10^24
1.15×10^-23
Answer:
2,47 * [tex]10^{24}[/tex] (molecules)
Explanation:
Avogadro's number is a very important relationship: 1 mole = 6,02 * [tex]10^{23}[/tex] atoms, molecules, protons, etc.
To convert from moles to molecules, multiply the molar amount by Avogadro's number.
4,1 mol * 6,02 * [tex]10^{23}[/tex] ≈ 24,7 * [tex]10^{23}[/tex] = 2,47 * [tex]10^{24}[/tex] (molecules)
Therefore the third answer is correct
A formula unit made with Na and unknown nonmetal "Z" has the formula, NaZ. Which element does "Z" represent?
What is the definition of lava?
Answer:
Lava, magma (molten rock) emerging as a liquid onto Earth's surface. The term lava is also used for the solidified rock formed by the cooling of a molten lava flow.
Explanation:
Racecar driver Keimesha was in a race and accelerated from rest to 39 m/s by the time she reached the finish line. Keimesha’s car moved in a straight line and traveled from the starting line to the finish line in 6.0 seconds. What was the acceleration of the dragster?
Answer:
the acceleration of the racecar is 6.5 m/s²
Explanation:
Given;
initial velocity of the racecar, u = 0
final velocity of the racecar, v = 39 m/s
time of motion, t = 6.0 s
The acceleration of the racecar is calculated as;
[tex]a = \frac{v-u}{t} \\\\a = \frac{39-0}{6} \\\\a = \frac{39}{6} \\\\a = 6.5 \ m/s^2[/tex]
Therefore, the acceleration of the racecar is 6.5 m/s²
The formation of tert-butanol is described by the following chemical equation: Suppose a two-step mechanism is proposed for this reaction, beginning with this elementary reaction: Suppose also that the second step of the mechanism should be bimolecular. Suggest a reasonable second step. That is, write the balanced chemical equation of a bimolecular elementary reaction that would complete the proposed mechanism.
Answer:
(CH3)3C^+ + OH^- --------> (CH3)3COH
Explanation:
This reaction has to do with SN1 reaction of alkyl halides. Here tert-butanol is formed from tert-butyl bromide.
The first step in the reaction is the formation of a carbocation. This is a unimolecular reaction. The rate of reaction depends on the concentration of the alkyl halide. This is a slow step and thus the rate determining step in the mechanism.
(CH3)3CBr -------> (CH3)3C^+ + Br^-
The second step is a fast step and it completes the reaction mechanism. It is a bimolecular reaction as follows;
(CH3)3C^+ + OH^- --------> (CH3)3COH
This group of fungi forms spores in a round structure on the end of a hyphae
Answer:
Is zygote fungi an option??
Answer:
zygote fungi
Explanation:
i got the answer right
Why was d-day and the battle of France so important to American and the allies
Answer:
The Importance of D-Day
The D-Day invasion is significant in history for the role it played in World War II. It marked the turn of the tide for the control maintained by Nazi Germany; less than a year after the invasion, the Allies formally accepted Nazi Germany's surrender.
Please answer this. List the three most abundant minerals in this bottle of mineral water.
What is the correct name for Hg(NO3)2?
Mercury (I) nitrate
Mercury (II) nitrate
Mercury nitroxide
Mercury dinitride
Answer: Hg(NO3)2 = Mercury (II) nitrate
The other answer is wrong. Mercury (I) nitrate is Hg2(NO3)2.
How is a magnetic field produced?
O when an electromagnetic field interacts with a magnet
O when a current runs through a conductor
O when an object has an electric charge
O when electrons move through a circuit
Answer:
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. ... Magnetic fields are produced by moving electric charges and the intrinsic magnetic moments of elementary particles associated with a fundamental quantum property, their spin.
Answer: when an electromagnetic field interacts with a magnet
Explanation:
According to the Bohr model of the atom, which particles are allowed to exist in any one of a number of energy levels?
Answer: the line-emission spectrum of an atom is caused by the energies released when electrons. releases energy of only certain values.
f) How many neutrons are there in the nucleus of arsenic?
1. Neodymium
2. Selenium
3. Strontium
Explanation:
How many neutrons are there in the nucleus of arsenic?42 neutrons
The nucleus consists of 33 protons (red) and 42 neutrons (blue).
What is the percent oxygen in Rb2Cr2O7
Answer:
28.9452
Explanation:
Answer:
28.9452%
Explanation:
Rb-44.1781
Cr-26.8767
O-28.9452
Calculate the kinetic energy of an electron ejected from a piece of sodium (Φ = 4.41x10–19 J) that is illuminated with 265 nm light.
in Joules
Answer:
Explanation:
Energy of falling radiation having wavelength of 265 nm
= h c / λ where h is plank's constant , c is velocity of light and λ is wavelength of radiation . Putting the values
Energy of light photon = 6.6 x 10⁻³⁴ x 3 x 10⁸ / 265 x 10⁻⁹
= .0747 x 10⁻¹⁷
= 7.47 x 10⁻¹⁹ J .
Work function of sodium is 4.41 x 10⁻¹⁹
So kinetic energy of ejected electron = energy of falling photon - work function
= 7.47 x 10⁻¹⁹ - 4.41 x 10⁻¹⁹
= 3.06 x 10⁻¹⁹ eV .
please help me with this problem
the amount of reactants = the amount of products
N2 + 3H2 --> 2NH3
Which has more calories: table sugar or aspartame?
Hello there!
Aspartame has 4 kilocalories of energy per gram and table sugar has 3.9 kilocalories. They are pretty much same but aspartame is 200 times sweeter than sucrose so probably would be aspartame that has more calories.
After two half-lives, how much of the original material has decayed? 25 percent 50 percent 75 percent 100 percent
The original material has decayed 75%
Further explanationGiven
two half-life
Required
The decayed sample
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
t = 2 x t 1/2
Input the value :
[tex]\tt \dfrac{Nt}{No}=\dfrac{1}{2}^2=\dfrac{1}{4}=25\%[/tex]
The amount of Nt = 25% No
From where do the placenta and umbilical cord develop?
Answer:
it develops from the womb
Answer:
outer cells of the blastocyst
Explanation:
on edg:)
Over an interval of 2.0 s the average rate of change of the concentration of C was measured to be 0.0540 M/s. What is the final concentration of A at the end of this same interval if its concentration was initially 2.000 M
Answer:
Explanation:
the average rate of change of the concentration =
( initial concentration - final concentration ) / time
Initial concentration = 2.000 M
the average rate of change of the concentration = .0540 M/s
time = 2 s
Putting the values
.0540 = (2.000 - X ) / 2
0.108 = 2.000 - X
X = 1.892 M .
Final concentration = 1.892 M .
la densidad de un aceite liviano para vehiculo es 0.87g/cm3 calcules su volumen especifico y peso especifico
Answer:
Pe = 8700 N/m³
Vesp = 1,15 cm³/g
Explanation:
Ya que conocemos el valor de la densidad de este aceite, es muy sencillo calcular tanto volumen como peso específico.
En el caso de volumen específico, esta se refiere al cociente del volumen de un líquido con su masa respectiva. En otras palabras, es el inverso de la densidad, por tanto usamos la siguiente expresión para el volumen específico:
Vesp = 1/d
Vesp = 1 / 0,87
Vesp = 1,15 cm³/gPara el caso del peso específico, se calcula como el cociente de la masa del líquido y su volumen que ocupa. Sin embargo no conocemos ninguno de esos dos datos, por lo que para calcular el peso específico solo basta multiplicar este valor por la aceleración de gravedad, que vamos a asumir para este problema que es 10 m/s². Y ademas cambiaremos las unidades de densidad de g/cm³ a kg/m³. Esto es porque las unidades de peso específico son N/m³ y los newton (N) son kg m/s².
d = 0,87 g/cm³ * (1 kg/1000g) * (100 cm/1m)³ = 870 kg/m³
Pe = 870 kg/m³ * 10 m/s²
Pe = 8700 N/m³ESpero te sirva.
if a gas at 300k occupies 3.60 liters at a pressure of 1.00 atm, what will be it’s new pressure if the volume is compressed to 2.0 liters at a temperature of 450K?
Answer: The new pressure if the volume is compressed to 2.0 liters at a temperature of 450K is 2.7 atm
Explanation:
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 1.00 atm
[tex]P_2[/tex] = final pressure of gas = ?
[tex]V_1[/tex] = initial volume of gas = 3.60 L
[tex]V_2[/tex] = final volume of gas = 2.0 L
[tex]T_1[/tex] = initial temperature of gas = [tex]300K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]450K[/tex]
Now put all the given values in the above equation, we get:
[tex]\frac{1.00\times 3.60}{300}=\frac{P_2\times 2.0}{450}[/tex]
[tex]P_2=2.7atm[/tex]
The new pressure is 2.7 atm
Why is it important to know gas properties at STP?
Answer:
STP values are most often cited for gases because their characteristics change dramatically with temperature and pressure. One common definition of STP is a temperature of 273 K (0° Celsius or 32° Fahrenheit) and the standard pressure of 1 atm. Under these conditions, one mole of a gas occupies 22.4 L.
Which of the following substances contains MOSTLY ionic bonding? A) LIF B) CO2 C) AICI: D) BeCl2 E) Cu
Answer: [tex]LiF[/tex] , [tex]AlCl_3[/tex] and [tex]BeCl_2[/tex]
Explanation:
An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element or the metal and the element which accepts the electrons is known as electronegative element or non metal.
A covalent bond is formed when an element shares its valence electron with another element. This bond is formed between two non metals.
[tex]LiF[/tex] , [tex]AlCl_3[/tex] and [tex]BeCl_2[/tex] contain ionic bonds as they aremade up of metals and non metals.
When 42.5 g of benzamide (C7H7NO) are dissolved in 500 g of a certain mystery liquid X, the freezing point of the solution is 6.40 °C less than the freezi point of pure X. Calculate the mass of iron(III) nitrate (Fe(NO3)3 that must be dissolved in the same mass of X to produce the same depression in freezing point.
Answer:
21.3g of Fe(NO₃)₃ are required to produce the same depression in freezing point of solution.
Explanation:
Freezing point depression is a colligative property which indicates, in determined mixture, the freezing point of solution is lower that the freezing point of the solvent, according the amount of solute.
Formula is: ΔT = Kf . m . i
Kf is the cryoscopic constant, which is particular for each solvent. We do not have that data, so we need to find it out in order to solve the question:
ΔT = Freezing point of pure solvent - Freezing point of solution.
This data is known → 6.40°C
m, means molality, moles of solute in 1kg of solvent. Let's get the moles of benzamide: 42.5 g . 1mol / 121g = 0.351 moles
m = 0.351 mol / 0.5kg = 0.702 m
As benzamide is an organic compound i, = 1. i are the number of ions dissolved in solution. Let's find out Kf:
6.40°C = Kf . 0.702 m . 1
6.40°C /0.702m = 9.11 °C/m.
Let's go to the next question.
ΔT is the same → 6.40°C
But this is, an inorganic salt, a ionic salt: Fe(NO₃)₃ → 1Fe³⁺ + 3NO₃⁻
For this case, we have 1 mol of Iron(III) and 3 nitrates, so i = 4
Let's replace data: 6.40°C = 9.11 °C/m . m . 4
6.40°C / (9.11 m/°C . 4) = 0.176 m
This data represents that, in 1 kg of solvent we have 0.176 moles of nitrate.
Mass of solvent X required in this case is 0.500 kg, so, the moles that are contained are: 0.500 kg . 0.176 mol/kg = 0.088 mol
Let's determine the mass of salt: 0.088 mol . 241.85g /1mol = 21.3 g
Which term is used to describe the variety
of inheritable traits in a species?
Ecosystem diversity
Genetic diversity
Natural selection
Species diversity
So, Ecosystem Diversity is a term that describes how different habitats of organisms are. For example, the fact that our planet has deserts, tundras but also estuaries is a sign of the diversity of its ecosystems. Species diversity refers to the number of different species that inhabit a specific ecosystem or the whole biosphere; the more, the better for species diversity. Genetic diversity is the term we are looking for; it means the variation in genes (usually in one species) that leads to different inheritable traits (in members of the same species). For example eye color is an inheritable trait that showcases genetic diversity since there are many genes that determine a different color such as brown, blue, green etc. (even though the environment plays a role too). Finally, natural selection is a theory about the survival of the fittest due to competition. It relates to inheritable traits and their diversity but it does not describe them.