Answer:
B. Experiments are rarely accurate, so it’s important to keep testing a hypothesis.
Explanation:
Calculate the number of copper atoms in a 63.55 g
sample of copper.
Answer:
there are N_A, "Avogadro's number" of copper atoms in a 63.55*g mass of copper wire. And N_A, "Avogadro's number" = 6.022xx10^23 individual copper atoms. I look on the Periodic Table, and at Z=29, i.e. copper, the quoted atomic mass is 63.55*g.
Explanation:
One mole of every substance contains 6.022×10²³ atoms. The atomic mass of copper is 63.55 g. Thus it is one mole of copper which contains copper 6.022×10²³ atoms.
What is copper?Copper is 29th element in periodic table. It is a transition metal classified into d-block. Transition metals are named so because they in between the metals and non-metals in periodic table.
Transition metals have varying oxidation state. Copper exists in +1, +2 and +3 oxidation states.
Any substance containing 6.022×10²³ atoms is called one mole of that substance. This number is called Avogadro number. Hence one mole of each element contains avogadro number of its atoms.
Similarly one mole of each compound contains 6.022×10²³ number of molecules. Here, the atomic mass of copper is 63.55 g. That is one mole of copper weighs 63.55 g. Hence, number of atoms in 63.55 g of copper is 6.022×10²³ atoms.
To find more about Avogadro number, refer the link below:
https://brainly.com/question/11907018
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Atoms are the smallest unit of an element that holds the physical identity of that element. T or F
Answer:
True
Explanation:
In the hydrogenation of ethylene using a nickel catalyst, the initial concentration of ethylene is 1.65 mol⋅L−1 and its rate constant (k) is 0.0014 mol⋅L−1⋅s−1 . Determine the rate of reaction if it follows a zero-order reaction mechanism.
Answer:
.0014 M/s ( (mol*L^-1 / s) )
Explanation:
Since the rate law of a zero order reaction is Rate = k[A]^0, the rate is .0014 * (1.65)^0 = .0014
How many grams of Pb are there in a sample of Pb that contains 1.15×1024 atoms? grams
[tex]\text{mass of Pb = 1.15 × 10²⁴ Pb atoms} × \frac{\text{1 mol Pb}}{\text{6.022 × 10²³ Pb atoms}} × \frac{\text{207.2 g Pb}}{\text{1 mol Pb}}[/tex]
[tex]\boxed{\text{mass of Pb = 396 g}}[/tex]
Sally rides her bike to the store to get some Skittles. The store is 5 km
away. If it takes her 10 minutes to get to the store what is her average
speed?
0.5 km/hr
0.5 mph
0.5 km/min
5 km/min
Answer:
Sally's average speed is 0.5 km/min
Explanation:
speed=distance/time
so, 5km/10min=0.5 km/min
Which object will have more potential energy (PE), a book on the edge of a small bookshelf or a penny sitting on the edge of the Empire State building? EXPLAIN your reasoning.
Answer: I dont know
Explanation: figure it out
An ideal gas in a sealed container has an initial volume of 2.80 L. At constant pressure, it is cooled to 18.00 °C, where its
final volume is 1.75 L. What was the initial temperature?
Answer:
[tex]T_1=-91.18\°C[/tex]
Explanation:
Hello there!
In this case, given the T-V variation, we understand it is possible to apply the Charles' law as shown below:
[tex]\frac{T_1}{V_1}= \frac{T_2}{V_2}[/tex]
Thus, since we are interested in the initial temperature, we can solve for T1, plug in the volumes and use T2 in kelvins:
[tex]T_1= \frac{T_2V_1}{V_2}\\\\T_1= \frac{(18.00+273.15)K(1.75L)}{(2.80L)}\\\\T_1=182K-273.15\\\\T_1=-91.18\°C[/tex]
Best regards!
Determine the enthalpy of neutralization in Joules/mmol for a solution resulting from 19 mL of 1 M NaOH solution and 19 mL of a HCl with the same molarity. If separately, each had a temperature of 28.6 degrees Celsius, and upon addition, the highest temperature reached by the solution was graphically determined to be 37.3 degrees Celsius. Round to the nearest whole number.
Answer:
[tex]\Delta _{neutralization}H=-73\frac{J}{mmol}[/tex]
Explanation:
Hello there!
In this case, by considering this calorimetry problem, it is possible to realize that the heat released by the reaction between HCl and NaOH is absorbed by the reaction mixture, which can be assumed to have the same density and specific heat of pure water; thus, we calculate this heat as a function of the specified temperature change:
[tex]Q_{rxn}=-Q_{solution}\\\\Q_{rxn}=-m_{solution}C_{solution}(T_2-T_1)[/tex]
Thus, we plug in the data, by also considering that the total volume of solution is 19mL+19mL=38mL:
[tex]Q_{rxn}=-(38mL*\frac{1g}{1mL} )(4.184\frac{J}{g\°C}) (37.3\°C-28.6\°C)\\\\Q_{rxn}=-1383.2J[/tex]
Next, since the reaction between NaOH and HCl is:
[tex]NaOH+HCl\rightarrow NaCl+H_2O[/tex]
Whereas there is 1:1 mole ratio of NaOH to HCl, we infer they both react with the same moles, defined by the volume and molarity:
[tex]n_{rxn}=0.019L*1mol/L\\\\n_{rxn}=0.019mol[/tex]
Finally, to compute the enthalpy of neutralization we divide the total heat due to the reaction by the reaction moles to obtain:
[tex]\Delta _{neutralization}H=\frac{Q_{rxn}}{n_{rxn}=}\\\\ \Delta _{neutralization}H=\frac{-1383.23J}{0.019mol}\\\\\Delta _{neutralization}H=-72801.6\frac{J}{mol}*\frac{1mol}{1000mmol}\\\\\Delta _{neutralization}H=-73\frac{J}{mmol}[/tex]
Best regards!
How many moles of carbon dioxide are produced when 0.25 mole of butane is consumed?
Answer:
1
Explanation:
Let's write the equation first:
[tex]C_{4}H_{10} + \frac{13}{2} O_{2} -> 4 CO_2 +5 H_{2}O[/tex]
So 1 mole of butane reacts to give 4moles of Carbon diOxide.
thus , 0.25 mole of butane will react to give = 4 * 0.25= 1 mole Carbon diOxide
True or false solar power take power from wind and uses it to make electricity
Which organism dna will differ the most from the leopard
Answer:
Lancelet
Explanation:
This is because a Lancelet is a small elongated marine invertebrate that lacks all of the physiological and biological traits of a leopard
Methane and sulfur react to produce carbon disulfide (CS₂), a liquid often used in the production of cellophane.
2CH₄ + S₈ --> 2CS₂ + 4H₂S
Calculate the moles of H₂S produced when 2.25 mol S₈ is used.
Answer:
9 moles
Explanation:
The balanced chemical equation provided in this question is as follows:
2CH₄ + S₈ → 2CS₂ + 4H₂S
In accordance to the above balanced equation, 1 mole of sulphur (S8) produces 4 moles of hydrogen sulfide (H2S).
Therefore, if 2.25mol of S8 is used, 2.25 × 4 = 9 mol
9 moles of H2S is produced.
Why do atoms connect to eachother?
Answer:
To keep from falling apart
Explanation:
d. If you were to open the carbonated drink bottle after shaking, what would you expect to happen and why? If you were to open the water bottle after shaking, what would you expect to happen and why?
Shaking causes small bubbles, which helps the soda's carbon dioxide escape faster. The gas will gradually escape from the liquid as bubbles once the can is opened, and the soda will become "flat." The dissolved gas takes a long time to escape if the liquid is treated gently.
An allele is a form of a gene? true or false
Answer:
true
Explanation:
How do prevailing winds affect air temperature?
Answer:
Explanation:
Prevailing winds bring air from one type of climate to another. For example, warm winds that travel over water tend to collect moisture as they travel; the water vapor in the air will condense as it moves into colder climates, which is why temperate coastal areas often receive heavy rainfall
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How to find the net ionic of an equation
What happens to the amplitude of waves when two waves overlap and are out of phase with each other?
Answer:
Also called superposition. When overlapping waves produce a wave with an amplitude that is the sum of the individual waves. When overlapping waves produce a wave with an amplitude that is less than the sum of the individual waves.
Explanation:
What class of chemicals is responsible for ozone depletion?
C3H8(g) + 5O2(g) ⟶ 3CO2(g) + 4H2O(g) H = -2220 kJ If 865.9 g of H2O is produced during this combustion, how much heat is generated? Do not include the negative sign in your answer. Express the answer to the nearest whole number, or round to the nearest ones place. The molar mass of H2O is 18.02 g/mol.
Answer:
3 × 10⁴ kJ
Explanation:
Step 1: Write the balanced thermochemical equation
C₃H₈(g) + 5 O₂(g) ⟶ 3 CO₂(g) + 4 H₂O(g) ΔH = -2220 kJ
Step 2: Calculate the moles corresponding to 865.9 g of H₂O
The molar mass of H₂O is 18.02 g/mol.
865.9 g × 1 mol/18.02 g = 48.05 mol
Step 3: Calculate the heat produced when 48.05 moles of H₂O are produced
According to the thermochemical equation, 2220 kJ of heat are evolved when 4 moles of H₂O are produced.
48.05 mol × 2220 kJ/4 mol = 2.667 × 10⁴ kJ ≈ 3 × 10⁴ kJ
Aqueous copper (II) sulfate reacts with aqueous potassium fluoride to produce
a precipitate of copper (II) phosphate and aqueous potassium sulfate.
Answer:
CuSO₄(aq) + 2 KF(aq) = CuF₂ + K₂SO₄
Explanation:
The question is missing but I think it must be about writing and balancing the equation.
Let's consider the unbalanced equation for the reaction that occurs when aqueous copper (II) sulfate reacts with aqueous potassium fluoride to produce a precipitate of copper (II) fluoride (I fixed a mistake here) and aqueous potassium sulfate. This is a double displacement reaction.
CuSO₄(aq) + KF(aq) = CuF₂ + K₂SO₄
Since only K and F atoms are not balanced, we will get the balanced equation by multiplying KF by 2.
CuSO₄(aq) + 2 KF(aq) = CuF₂ + K₂SO₄
What is the molecular geometry of COF2?
Answer:
trigonal planar
Explanation:
What is the precipitation like in the arctic tundra?
Use this website to answer the question: https://thewildclassroom.com/biomes/artictundra-2/
Question 4 options:
In summer, it typically rains less than 5 cm (<2 inches), while in winter it rains 25–44 cm (10–17 inches).
There is an average of 20 – 35 inches of rainfall a year.
The range is from 15-25cm (6-10 inches) a year where most falls as snow.
It can can also be called a cold desert due to its lack of precipitation.
Answer:
In summer, it typically rains less than 5 cm (<2 inches), while in winter it rains 25–44 cm (10–17 inches).
Explanation:
because tundra vegetation is mostly found in desert areas
how many atoms of carbon are in a diamond with a mass of 0.568 g?
Answer:
There are 2.85 x 10^22 atoms of carbon in a diamond with a mass of 0.568 g.
Hope this helps! :)
> Question 20 3.3 pts A gas occupies 500.0 mL at a temperature of 27.0°C. What is the volume at 15.0°C? (Remember to convert °C to Kelvin.) Use Charles' Law V1T2 = V2T1 © 1500 O 480 0 350 900
Answer:
480.0 mL
Explanation:
Step 1: Given data
Initial volume (V₁): 500.0 mLInitial temperature (T₁): 27.0 °CFinal volume (V₂): ?Final temperature (T₂): 15.0 °CStep 2: Convert the temperatures to the Kelvin scale
We will use the following expression.
K = °C + 273.15
K = 27.0°C + 273.15 = 300.2 K
K = 15.0°C + 273.15 = 288.2 K
Step 3: Calculate the final volume
Assuming ideal behavior and constant pressure, we can calculate the final volume using Charles' law.
V₁ × T₂ = V₂ × T₁
V₂ = V₁ × T₂ / T₁
V₂ = 500.0 mL × 288.2 K / 300.2 K = 480.0 mL
USA test prep wave 1 performance task
Answer:
Performance Tasks 188; Instructional Videos 75
Explanation:
A percent composition analysis yields
22.6% phosphorus (P) and 77.4%
chlorine (CI). What is the empirical
formula for the compound?
А
B
P2C17
PCI:
Answer:
PCl₃
Explanation:
To determine the empirical formula of a compound, we need to follow a series of steps.
Step 1: Divide each percent composition by the atomic mass of the element
P: 22.6/30.97 = 0.729
Cl: 77.4/35.45 = 2.18
Step 2: Divide all the numbers by the smallest one, i.e. 0.729
P: 0.729/0.729 = 1
Cl: 2.18/0.729 ≈ 3
The empirical formula of the compound is PCl₃.
what type of forces are unequal forces that cause a change in an object's motion such as speed or direction
Answer:
Unbalanced forces are not equal, and they always cause the motion of an object to change the speed and/or direction that it is moving.
Explanation:
When two unbalanced forces are exerted in opposite directions, their combined force is equal to the difference between the two forces.
The magnitude and direction of the net force affects the resulting motion
This combined force is exerted in the direction of the larger force
For example, if two students push on opposite sides of a box sitting on the floor, the student on the left pushes with less force (small arrow) on the box than the student on the right side of the box (long arrow).
The resulting action (net force: smaller arrow to the right of the = shows that the box will change its motion in the direction of the greater force
If unbalanced forces are exerted in the same direction, the resulting force (net force) will be the sum of the forces in the direction the forces are applied.
When forces act in the same direction, their forces are added. When forces act in opposite directions, their forces are subtracted from each other.
Unbalanced forces also cause a nonmoving object to change its motion
If there is no net force acting on the object, the motion does not change. If there is a net force acting on an object, the speed of the object will change in the direction of the net force.
A diver takes a balloon with a volume of 2.5Lfrom the surface, where the pressure is 1.0 atm, to a depth of 20m, where the pressure is 3.0 atm. What happen to the volume of the balloon? What if the end of the subnerged balloon is on a long pipe that goes to the surface and is attached to another balloon?
Answer:
The explanation is given below:
Explanation:
As we know that the volume is inversely proportional to the volume. If the pressure is rising from 1 atm to 3 atm so the volume of the ballon would decrease
P_1V_1 = P_2V_2
1.0 × 2.5L = 3 × V_2
V_2 = 0.833L
Since the air is moving from high pressure to low pressure and the two ballons are interconnected via a long pipe so the movement of the air is from bottom to top
An electromagnet is the most powerful type of magnet there is. It is a magnet with a current running through it that can be turned on and off. Why might it be useful to be able to turn the electromagnet on and off?(1 point) 1
to not waste electricity
to control the strength of the magnet
to reduce wearing out of the magnet over time
to latch onto and let go of objects
What does electric current measure?(1 point) 2
how quickly electrical energy moves in a circuit
how frequently electrical energy moves in a circuit
how much electrical energy moves in a circuit
how well electrical energy moves in a circuit
How is a magnetic field produced?(1 point) 3
when an object has an electric charge
when electrons move through a circuit
when a current runs through a conductor
when an electromagnetic field interacts with a magnet
Which statement best describes how an electromagnetic motor works?(1 point) 4
Electrons are moved through a magnet, creating a circuit. That circuit interacts with a current, moving the conductor in the orientation of the field.
Electrons are moved through a circuit, creating a current. That current interacts with a magnet, moving the conductor in the orientation of the field.
Electrons are moved through a current, creating a circuit. That circuit interacts with a magnet, moving the conductor in the orientation of the field.
Electrons are moved through a magnet, creating a current. That current interacts with a circuit, moving the conductor in the orientation of the field.
Electromagnetism in Use Quick Check
5 of 5Items
Item 5
Use the image to answer the question.
A diagram shows a wire carrying a current in vertical direction. The magnetic field drawn using compass needles around the wire are concentric circles in a plane perpendicular to the direction of current.
What are the particles demonstrating in this image?
(1 point) 5
electric field
electromagnetic field
electromagnetic motor
magnetic field
Answer:
1. to latch onto and let go of eggs
2. how quickly electrical energy moves in a circuit
3. when a current runs through a conductor
4. Electrons are moved through a circuit, creating a current. That current interacts with a magnet, moving the conductor in the orientation of the field.
5. electromagnetic field