A nitrogen gas collected in a tube has a volume of 0.86 mL, a temperature of 316.48 degrees kelvin, and a pressure 1.17 atm. Two days later, the volume of the nitrogen was 1.06 mL but the pressure did not change. What was the temperature two days later
Scientists examine the light spectra from distant stars to determine if the size of the universe is changing. Why do astronomers believe the size of the universe is changing?
options:
The red shift indicates that distant galaxies are moving away from each other.
The red shift indicates that distant galaxies are moving towards each other
The blue shift indicates that distant galaxies are moving away from each other
The blue shift indicates that distant galaxies are moving towards each other
Answer: A
Explanation:
Red shifting occurs when objects move away from each other. You can think of the light wave being "stretched." A stretching of the wave causes a higher wavelength, and less energy, which are the characteristics of red light.
Give two examples of an ionic compound?
pls answer ASAP pls & ty aha
when you change the shape of a ball of clay, you are changing the amount of mass , true or false
Answer:
if you change the shape wouldn't it still have the same mass and volume because the density remains the same? so I think it is false
Answer:
False
Explanation:
when you change the shape of the ball of clay, it does not change mass or volume, your not adding more just changng it's form. You can only change it's mass or volume by adding more or breaking it into less.
When an object heats up , it
Answer:
gains thermal energy. the thermal energy is kinetic energy at the molecular scale, and friction and stuff
1. Calculate the amount of energy given off when 17 g of vapor at 102C condenses to 87C
Did a phase change occur? If so, which one? Is this endothermic or exothermic?
Answer:
- Amount of energy = -1066.92 J
- Yes, a phase change occurs from gaseous state to liquid state
- It is exothermic
Explanation:
Using Q = m × c × ∆T
Where Q = amount of energy
m = mass = 17g
c = specific heat capacity of water (4.184J/g°C)
∆T = change in temperature (87°C - 102°C = -15°C)
Hence, Q = m × c × ∆T
Q = 17 × 4.184 × (-15°C)
Q = -1066.92 J
- According to this question, vapor condenses i.e. gaseous form of water changes to liquid water, which involves a reduction in temperature. Hence, a change of phase occurs from gaseous state to liquid state.
- Since the change of phase occurs from a less orderly state (gas) to a more orderly state (liquid), there is a release of energy i.e. EXOTHERMIC. The amount of energy or Enthalpy change (∆H) is negative
To what volume should 25 ml of 15 M nitric acid be diluted to prepare a 3.0 M solution?
Answer:
We can use the dilution formula to find the volume of the diluted solution to be prepared
c1v1 = c2v2
Where c1 is concentration and v1 is volume of the concentrated solution
And c2 is concentration and v2 is volume of the diluted solution to be prepared
Substituting the values in the equation
15 M x 25 mL = 3 M x v2
v2 = 125 mL
The 25 mL concentrated solution should be diluted with distilled water upto 125 mL to make a 3 M solution
According to the big bang theory, the universe—all of the stars, planets, and galaxies everywhere—began as a very small, dense mass. This mass expanded suddenly in an incredibly hot explosion-like event, and it has spent the last 13.7 billion years rapidly expanding and cooling.
In 1964, which of the following space technologies provided scientists with the best evidence that the universe was created in the big bang?
A.
a lunar module
B.
a Mars rover
C.
a radio telescope
D.
a weather satellite
the table which shows some information about four organic compounds P, Q, R and S and answer the question that follow.
1.Which Homologous series does C3H8 belong to ?Give its general formula.
2. Predict the chemical formula of the next two members of this homlogous series.
3. Based on the information given above, state one chareceristics of the homologous series
Answer:
1. Alk
2.The molecular formula of two members of a homologous series are C 3 H 4 and C 6 H 1 0
3.
same functional group
physical properties
formula compounds are the same
Alkanes are simple saturated hydrocarbons with its first member as methane.
Alkanes have low melting and boiling points.
What are alkanes?Alkanes are saturated hydrocarbons whose names end with -ane which have its simplest and first member as methane.
The homologous series to which the compound C3H8 belongs to is alkanes.
Alkanes have the general molecular formula given below:
[tex]C_nH_{2n + 2}[/tex]
[tex]The \: next \: two \: member \: of \: the \: series \: are \: C_7H_16 and C_8H_18[/tex]
The alkanes usually have low melting and boiling points.
Therefore, alkanes are simple saturated hydrocarbons.
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A balloon of helium was put in the freezer at -23°C. Its volume at this temperature was 2.5 liters. It was removed from the freezer. Eventually, it reached a temperature of 177°C. What would its volume be at this temperature? (Neglect any force used to stretch the rubber balloon.)
Answer:
4.5 L
Explanation:
From Charles law;
V1/T1 = V2/T2
Where;
V1= initial volume = 2.5 L
T1 = initial temperature = -23°C + 273 = 250 K
V2 = final volume = unknown
T2 = 177°C +273 = 450 K
Making V2 the subject of the formula
V2 = V1 T2/T1
V2 = 2.5 × 450/250
V2 = 4.5 L
I NEED HELP ASAP! PLEASE BE GENUINE
1. A sample of an unknown gas effuses in 11.1 min. An equal volume of H2 in the same apparatus under the same conditions effuses in 2.42 min. What is the molar mass of the unknown gas? (MM of H2 = 2.02 g/mol)
2. A steel tank has a volume of 438 L and is filled with 0.885 kg of O2. Calculate the pressure of O2 at 21.0 degrees Celsius. (MM of O2 = 32.00 g/mol)
PLEASE INCLUDE THE GIVEN AND REQUIRED! :)
1. The molar mass of the unknown gas obtained is 0.096 g/mol
2. The pressure of the oxygen gas in the tank is 1.524 atm
Graham's law of diffusionThis states that the rate of diffusion of a gas is inversely proportional to the square root of the molar mass i.e
R ∝ 1/ √M
R₁/R₂ = √(M₂/M₁)
1. How to determine the molar mass of the gas Rate of unknown gas (R₁) = 11.1 minsRate of H₂ (R₂) = 2.42 minsMolar mass of H₂ (M₂) = 2.02 g/mol Molar mass of unknown gas (M₁) =?R₁/R₂ = √(M₂/M₁)
11.1 / 2.42 = √(2.02 / M₁)
Square both side
(11.1 / 2.42)² = 2.02 / M₁
Cross multiply
(11.1 / 2.42)² × M₁ = 2.02
Divide both side by (11.1 / 2.42)²
M₁ = 2.02 / (11.1 / 2.42)²
M₁ = 0.096 g/mol
2. How to determine the pressure of O₂From the question given above, the following data were obtained:
Volume (V) = 438 L Mass of O₂ = 0.885 kg = 885 gMolar mass of O₂ = 32 g/mol Mole of of O₂ (n) = 885 / 32 = 27.65625 molesTemperature (T) = 21 °C = 21 + 273 = 294 KGas constant (R) = 0.0821 atm.L/Kmol Pressure (P) =?The pressure of the gas can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
Divide both side by V
P = nRT / V
P = (27.65625 × 0.0821 × 294) / 438
P = 1.524 atm
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URGENT  Please I need help answering these two questions ASAP
What does this represent about the type of change
happening in the container?
Theresa creates an experiment where she mixes two
red-colored substances together in a container and
observes the solution slowly changing from red to blue
for the next eight minutes. The solution becomes
completely blue after eight minutes.
O A chemical change started immediately and finished
at eight minutes.
O A non-chemical change started immediately and
finished at eight minutes.
O A chemical change occurred at four minutes.
O A non-chemical change occurred at four minutes.
Answer:
A
Explanation:
A chemical change started immediately and finished at eight minutes
Answer:
The answer is
A.) A chemical change started immediately and finished
at eight minutes.
Explanation:
which is the correct molecular structure for carbon dioxide
=> It is centrosymmetric and linear .
√so in that case carbon dioxide has no electric dipole.Explanation:
The central carbon atom is joined to two oxygen atoms by covalent double bonds
TRUE OR FALSE:
Most living organisms are composed of cells
Answer:
True
Explanation:
Everything is made up of matter, therefore everything (living) is made up of cells.
This statement is True.
All living organisms are composed of one or more cells. Cells are what make up our bodies. Cells are the basic unit of life.
A mixture of three noble gases has a total pressure of 1. 25 atm. The individual pressures exerted by neon and argon are 0. 68 atm and 0. 35 atm, respectively. What is the partial pressure of the third gas, helium? Use P subscript T equals P subscript 1 plus P subscript 2 plus P subscript 3 plus ellipses plus P subscript n. 0. 22 atm 0. 33 atm 1. 03 atm 2. 28 atm.
The partial pressure of the third gas, helium will be [tex]P_h=0.22\ atm[/tex]
What is partial pressure?According to Dolton's law of partial pressure if the mixture of gases exists in a container then the total pressure exerted by the gas will be the sum of the partial pressure of each case.
Now from the question, it is given
The total pressure of the three noble gases [tex]P_t=1.25\ atm[/tex]
The individual pressure of Neon= 0.68 atm
The individual pressure of argon=0.35 atm
The partial pressure of the third gas will be:
[tex]P_t=P_A+P_N+P_H[/tex]
[tex]P_H=P_T-P_A-P_N[/tex]
[tex]P_H=1.25-0.68-0.35=0.22\ atm[/tex]
Hence the partial pressure of the third gas, helium will be [tex]P_h=0.22\ atm[/tex]
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Answer:
a. .22
Explanation:
What must occur for a change to be a chemical reaction? a. There must be a change in chemical properties. b. There must be a change in physical properties. c. The change must involve a change in mass. d. The change must involve a change in volume. Please select the best answer from the choices provided A B C D Mark this and return
Answer:
A. There must be a change in chemical properties.
At least 2 or 3 atoms must change for it to be considered chemical. There must be some type of reactants that will change this. Otherwise, it's not a chemical reaction.
Hope this helps!
PLEASE HELP ASAP DUE INNA COUPLE MINUTES ILL MARK BRAINLIEST JUST HELP QUCIK
Answer: This occurs becuase the wall is more positively charged than the ballon. As the wall and balloon come in contact the balloon sticks due to the rule that opposites attract meaning positive attracts negative. The negatively charged balloon attracts the electrons in the paper because it's positive since positive attracts negative.
Explanation:
Which of the following statements is true about the subatomic particles of an
atom?
O Protons weigh less than electrons.
Protons weigh less than neutrons.
O Protons and neutrons have the same mass.
Electrons weigh more than neutrons.
ctor
O None
Answer:
B. Protons weigh less than neutrons.
Explanation:
Option 1: Wrong
The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom.
Option 2: Correct
Neutron's second down quark is heavier than the proton's second up quark. So the greater mass of this down quark gives the neutron a greater mass than the proton.
Option 3: Wrong
The proton and neutron have similar, but not identical masses. Either of these particles has a mass approximately 2000 times greater than the mass of an electron. ... The electrons make the greatest contribution to the chemical properties of the atom.
Option 4: Wrong
A neutron is made up of 2 down quarks and 1 up quark, bound together by 3 gluons. A proton is made up of 1 up quark and 2 down quarks, again, bound together by 3 gluons. The up quark is the lightest quark, and any other type is heavier. Both hadrons have 3 gluons, an up and a down quark in common. The only particles left are an up quark from the proton and a down quark from the neutron. Since any other quark is heavier than an up quark, the down quark is heavier. And same+lighter<same+heavier.
A proton and a neutron have a mass approximately 2000 times (x1836) of an electron each.
What contribution did J.J. Thomson make to the development of atomic theory?
A said that atoms are solid masses
B showed that electrons surround a dense nucleus
C found that atoms are made of smaller particles
D proposed that atoms contain electric fields
Answer:
C found that atoms are made of smaller particles
Explanation:
Thomson's discovery of the electron proved the existence of subatomic particles.
The contribution that J. J. Thomson makes to the development of atomic theory is as follows:
He found that atoms are made of smaller particles.Thus, the correct option for this question is C.
What is Atomic theory?Atomic theory may be defined as a scientific theory that demonstrates that each matter on the earth's surface s composed of particles called atoms. Atoms bear specific physical as well as chemical properties.
In this scientific theory, J. J. Thomson makes his contribution by stating that atoms are made of smaller particles. Apart from this, he was also well-known for the discovery of electrons. But he failed in obtaining the exact position of electrons.
This kink of the actual position of electrons was solved by Ernest Rutherford by stating that electrons surround a dense nucleus.
Therefore, atoms are made of smaller particles is the contribution that J.J. Thomson make to the development of atomic theory.
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How many moles of C are in the sample?
Answer:
I need more information
Explanation:
Which of the following is a sign that a chemical change is taking place?
Select one:
A.
a substance melting at high heat
B.
an object breaking into pieces
C.
a blue solid dissolving in water and changing the water to a blue colour
D.
an offensive odor emitting after two liquids are mixed
Answer:
C. a blue solid dissolving in a water and changing the water to a blue colour
Explanation:
For each of the following sets of atoms, rank them from lowest to highest
electronegativity.
a. N, Li, C
b. O, C, Ne
c. B, P, Si, o
d. Ca, F, Mg, P
e. He, S, F
Answer:
E
Explanation:
Well fluorine has the highest electronegativity.
Matter in a _______ has ______volume and ______ shape.
Answer:
Matter in a solid state has definite volume and definite shape.
Explanation:
The solid matter has the property of definite shape and volume because the molecules present in a solid are tightly packed so the molecules do not flow and there is no change in volume and force of attraction between the molecules will be very high that shows rigidity of molecule.
Polymers have very __________ molecules. Which word completes the sentence?
Answer:
Large
Explanation:
Polymers have very large molecules called macromolecules
what's the purpose of a compounds lab
Answer:
The purpose of a lab report is to organize and communicate what you did in your experiment.
Explanation:
Answer:
Compound microscopes are used to view small samples that can not be identified with the naked eye.
Explanation:
These samples are typically placed on a slide under the microscope. When using a stereo microscope, there is more room under the microscope for larger samples such as rocks or flowers and slides are not required.
Hope this helps :)
How many zeros are in the measurement 0.000040200 m are significant?
Answer:
It’s 3
Explanation:
a. Magnesium and Fluorine
b. Sodium and Fluorine
c. Sodium and Oxygen
d. Aluminium and Iodine
2. Write the chemical formula using the 4-step method for:
a) Magnesium sulphide,
b) Magnesium Fluoride,
c) Hydrogen Bromide and
d) Iron (III) Oxide.
Answer:
1)
a. MgF₂
b. NaF
c. Na₂O
d. AlI₃
2)
a. MgS
b. MgF₂
c. HBr
d. Fe₂O₃
Mercury, Venus, and Earth are the three planets closest to the sun. Would their combined distance from the sun be greater or less than the distance from the sun to Neptune? Show your work and justify your answer.
Answer: No, see below for explanation
Explanation:
Distance from Sun to Mercury = 57.91 million km
Distance from Sun to Venus = 108.2 million km
Distance from Sun to Earth = 149.6 million km
So their combined distance from the sun is = ( 57.91 + 108.2 + 149.6 ) million km = 315.71 million km
Distance from Sun to Neptune = 4.495 billion km
Convert this distance to millions = 4.495 * 1000 million km
= 4495 million km
It is clear that combined distance of Mercury, Venus & Earth from the Sun is much less than the distance from the Sun to Neptune
You spend 272 minutes in chemistry class each week. How many minutes will you spend in
chemistry at the end of the school year if the school year is 36 weeks long?
Answer:
1 week = 272 minutes
36 weeks = 272*36
= 9792 minutes