Answer:
C₂H₆
Explanation:
The formula for ethane is C₂H₆
Explain if the combination of iron and copper sulfate is an example of a chemical reaction. Use evidence and scientific reasoning to support your answer.
Which of these reactions shows simple chemical decomposition?
I2 + 2NaCl → 2Nal + Cl2
NaF + HCl → HF + NaCl
H2 + I2 → 2HI
2NaCl → 2Na + Cl2
Answer:
last option is the correct answer
Explanation:
you can see that the chemical NaCl is decomposed or broken into its components Na and Cl.
all other equations have formation of a new compound by reaction of 2 elements or compound
Calculate the molality of a solution that contains 51.2 g of naphthalene, C10H8, in 500 mL of carbon tetrachloride. The density of CCl4 is 1.60 g/mL.
Answer: The molality of naphthalene solution is 0.499 m
Explanation:
Density is defined as the ratio of mass and volume of a substance.
[tex]\text{Density}=\frac{\text{Mass}}{\text{Volume}} [/tex] ......(1)
Given values:
Volume of carbon tetrachloride = 500 mL
Density of carbon tetrachloride = 1.60 g/mL
Putting values in equation 1, we get:
[tex]\text{Mass of carbon tetrachloride}=(1.60g/mL\times 500mL)=800g[/tex]
Molality is defined as the amount of solute expressed in the number of moles present per kilogram of solvent. The units of molarity are mol/kg. The formula used to calculate molarity:
[tex]\text{Molality of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Mass of solvent (in g)}}[/tex] .....(2)
Given values:
Given mass of naphthalene = 51.2 g
Molar mass of naphthalene = 128.17 g/mol
Mass of solvent = 800 g
Putting values in equation 2, we get:
[tex]\text{Molality of naphthalene}=\frac{51.2\times 1000}{128.17\times 800}\\\\\text{Molality of naphthalene}=0.499m[/tex]
Hence, the molality of naphthalene solution is 0.499 m
Which of the following would have the best thermal insulation properties?
A. A cotton sweater
B. A rubber rain_at
C. A down-filled coat
D. A nylon windbreaker
Answer:
C. A down-filled coat via a p e x
Thermal insulation maintains the temperature inside the system and inhibits heat transfer. A down-filled coat would have the best thermal insulation properties. Thus, option C is correct.
What is thermal insulation?Thermal insulation is the property of the substance to resist the heat and energy transfer from a substance of abundance to a lesser concentration. They lack the conducting particles.
It inhibits the heat to get transferred to other substances. The minimum heat transfer is achieved by the structural formation and the choice of the substance.
A down-filled coat is made of insulation material that keeps warm during the winters as its structure can trap and retain heat making the person warm during colds.
Therefore, option C. A down-filled coat best shows thermal insulation.
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1 When the equation
Hg + Agt → __Ag + Hg2+
is correctly balanced using smallest whole numbers, the
coefficient in front of the Ag+ will be
A 5
B 2.
C 3
D 4.
Answer: I think 5
Explanation:
Balanced equations use the whole numbers to conserve the atomic numbers. When the reaction is balanced then 2 will be the coefficient in front of the Ag⁺.
What is a balanced reaction?A balanced reaction has symbols and whole numbers that represent the number of atoms and molecules of the reactants and the products in a reaction mixture.
The reaction between mercury and silver is shown as:
Hg + 2Ag⁺ → 2Ag + Hg²⁺
This can be checked by the redox half-reactions as:
2Ag⁺ + 2e⁻ → 2Ag⁰
Hg⁰ → Hg²⁺ + 2e⁻
Therefore, the silver cation gained two-electron and became a silver atom.
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how does a scientist answer a scientific question
Answer:
Observes and measure
Explanation:
Answer:
they use tests
Explanation:
they search for evidence using experiments,an experiment is a test to see if their explanation is right or wrong. evidence is made up of observations a scientist makes during an experiment
At the carnival, a baby was given a helium balloon whose
pressure equaled the atmospheric pressure at the carnival
which was 102.7 kPa. However, the baby wasn't paying
attention and the balloon floated away into the troposphere
where the atmospheric pressure is 97.8 kPa. What is the
positive difference between the pressure in the balloon and
the pressure of the troposphere in atm?
atm
Answer: 0.048 kPa
Explanation: no clue i just looked it up you’re welcome y’all:)
Chem pls help me thanks very much
Answer:
Flourine reacts with Sodium bromide to give Silver flourine and Bromine
Hope u understand
Thank You
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Answer:
posaaaaaaaaaaaaaaaaaaaaa
When choosing a respirator for your job, you must conduct a _____ test.
A) Weight
B) Breathing
C) Fit
D) Practice
(b) Given that ΔG° for reaction 1 is positive (155kJ/molrxn), what must be true about the sign of ΔH° for the reaction? Justify your answer
Answer: The sign of ΔH° for the reaction is positive.
Explanation:
Given: [tex]\Delta G^{o}[/tex] = 155 kJ/mol (1 kJ = 1000 J) = 155000 J/mol
The relation between [tex]\Delta G^{o}[/tex] and [tex]\Delta H^{o}[/tex] is as follows.
[tex]\Delta G^{o} = \Delta H^{o} - T \Delta S[/tex]
As the given value of [tex]\Delta G^{o}[/tex] is positive. This means that on further calculation the value of [tex]\Delta H^{o}[/tex] will come out to be positive.
Thus, we can conclude that the sign of ΔH° for the reaction is positive.
In a closed system, the amount of the non-expansion work that can be done is called gibs free energy. The enthalpy cahnge will be positive.
What is enthalpy?The enthalpy of the system is given as the addition of products of the pressure and the volume with the internal energy of the system.
The Gibbs free energy is given by the formula:
[tex]\rm \Delta G^{\circ} = \Delta H ^{\circ} - T\Delta S[/tex]
When Gibbs's free energy is positive then the enthalpy will become positive.
Therefore, the enthalpy change will be positive.
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Please help me school ends tomorrow
Which scenario describes a transfer of mechanical energy to heat and sound energy?
Question 7 options:
A)
a plant using energy from the sun to create food
B)
a very high pitched sound causing a glass to break
C)
talking into a microphone.
D)
clapping hands
Answer:
D) clapping handsExplanation:
hope it's helpful
What is the pressure exerted by 68.0 g of nitrogen trihydride gas in a 50.0L container at 30.0 C?
Answer:
Molecular mass of NH3 = ( 14 + 3 ) = 17 g
[tex]PV = \frac{m}{m _{r}} RT \\ P \times 50.0 \times {10}^{ - 6} = \frac{68.0}{17} \times 8.314 \times (30.0 + 273) \\ P = \frac{68.0 \times 8.314 \times 303}{17 \times 50.0 \times {10}^{ - 6} } \\ P = 2.02 \times {10}^{8} \: Pascals[/tex]
Calculate the standard free energy change, ΔG°, for the following at 25 °C:
MgO(s) + C(graphite) ® Mg(s) + CO(g)
ΔH° = 491.18 kJ ΔS° = 197.67 J/K
Answer:
Explanation:
here is your answer:
In a lab experiment, the decay of a radioactive isotope is being observed. At the beginning of the first day of the experiment the mass of the substance was 200 grams and mass was decreasing by 11% per day. Determine the mass of the radioactive sample at the beginning of the 10th day of the experiment. Round to the nearest tenth (if necessary).
Answer:
The correct answer is - 62.36 g.
Explanation:
Given:
Mass of substance - 200
decreasing rate - 11% per day
mass at the beginning of the 10th day - ?
Solution:
F(x) = 200*(1 - 11)^x
here x the time
F(x) = 200* (0.89)^10
= 200*0.3118
= 62.3634
Thus, the correct answer is 62.36 g.
write the recation of formation of ions by fluorine and potassium
Answer: The reaction of formation of ions by fluorine and potassium is [tex]K^{+} + F^{-} \rightarrow KF[/tex].
Explanation:
Atomic number of potassium is 19 and its electronic distribution is 2, 8, 8, 1. So, in order to attain stability it needs to lose 1 electron due to which it forms [tex]K^{+}[/tex] ion.
Atomic number of fluorine is 9 and its electronic distribution is 2, 7. In order to attain stability it needs to gain one electron and hence forms [tex]F^{-}[/tex] ion.
Therefore, when both these ions come in contact with each other then it leads to the formation of KF compound.
The reaction equation for this is as follows.
[tex]K^{+} + F^{-} \rightarrow KF[/tex]
Thus, we can conclude that the reaction of formation of ions by fluorine and potassium is [tex]K^{+} + F^{-} \rightarrow KF[/tex].
how many elements have been discovered so far by scientists
Answer:
118 elements have been discovered so far
Explanation:
Choose all the answers that apply.
Plasma is made of _____.
ions
clumped atoms
neutral atoms
free electrons
free protons
Answer:
neutral atoms
Explanation:
What is a mixture called when it has its different components mixed unevenly within the substance?
Heterogeneous mixture
Homogeneous mixture
Impure mixture
Pure mixture
Answer:
Heterogeneous mixture...is the answer
The dude above me is right. I thought he was wrong, so I put A but it turns out he was right!
When you perform a stoichiometry calculation, you are determining the ...
A) actual yield
B) theoretical yield
C) percent yield
Answer:
B. Theoretical yield
Explanation:
Hope its help:)
the swallowtail caterpillar is an example of a ?
Answer:
B) Consumer COnsumer COnsumer
Answer:
Consumer
Explanation:
It is a consumer
An inflated balloon contains X air molecules.After some time the volume of the balloon is found to be the half at the same temperature and pressure when a few air molecules are expelled out. a)How many molecules will be there in the balloon now? b) Which is the gas law associated with this?
Answer:
See explanation
Explanation:
According to Avogadro's law, the volume of a given mass of gas is directly proportional to the number of molecules of gas present at constant temperature and pressure.
Hence; V1/n1 = V2/n2
The implication of this is, if there were X molecules present and the volume of the balloon is halved, the number of molecules of gas present is also halved. So, we now have X/2 number of gas molecules present in the balloon.
This is in accordance with the statement of Avogadro's law.
what is the product of the reaction between arsenic and oxygen
a. AsO
b. AsO2
c. As3O2
d.As2O3
Answer:
d
Explanation:
As + O2 -------->as2o3
Which statement describes an Arrhenius acid
Answer:
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs. Hence, the correct statement is arrhenius acid produces hydrogen ions in solution.
You have learned how to take steps that are exactly 1m long. You take 12 steps north, then 15 steps north, 35 steps south, 11 steps south, then 16 steps north. What distance have you walked? What is your total displacement?
Answer:
you have walked 69 steps but your current location is -13
Which characteristic of water allows its molecules to form hydrogen bonds? (1 point)
Answer:
Water molecule is polar.
Explanation:
The partial negative charge on the O of one molecule can form a hydrogen bond with the partial positive charge on the hydrogens of other molecules.
a molecule made of carbon and oxygen atoms
Answer:
Carbon monoxide
Explanation:
The molecule has the carbon and oxygen atoms in equal amounts.
What must happen to the atoms before they are accelerated in the mass spectrometer?
Answer:
Atoms and molecules can be deflected by magnetic fields - provided the atom or molecule is first turned into an ion. Electrically charged particles are affected by a magnetic field although electrically neutral ones aren't. The atom or molecule is ionised by knocking one or more electrons off to give a positive ion.
Explanation:
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The atom must first be ionized.
The mass spectrometer is an important analytical tool in chemistry. It is used to identify atoms and molecules.
However, the atom or molecule to be analysed must first be converted into an ion.
This happens when the instrument imparts an electrical charge to the molecule or atom then the electrically charged ions are read as electrical current. The ion is accelerated towards a detector which analyses the deflected ions.
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Why do we not see a solar and lunar eclipse every lunar cycle?
Answer:
Explanation: We don't see lunar eclipses every cycle because the Moon's orbit is tilted five degrees from Earth's orbit around the Sun. And when an eclipse occurs the earth passes directly between Sun and Moon.
The photographs show comb jellies and an anglerfish in a benthic ecosystem
Which feature of these organisms' bodies allows them to withstand the
extreme pressure of this environment?
The organism in the bethic zone can survive in such high pressure area. This is because the organism there have no air pockets that provides them the ability to be balanced in the water
For which of the following prostheses would biocompatibility not be a serious
issue?
A. A hearing aid
B. Contact lenses
C. An engineered arm connected to nerve endings so that it can
respond to brain signals
D. A heart valve
a hearing aid.
it doesn't get in contact with fluids (like contact lenses) and doesn't get implanted, so it got not much to do with the immune system
Answer:
hearing aid
Explanation:
i just took tha test
