Answer:
Explanation:
the sum of number of proton and neutron is known as atomic mass
so if number of proton is 4 and neutron is 5 then atomic mass of an atom is 9
How many liters of blood does a human body have
Answer:
20000
Explanation:
Johnny has thrown a 2kg ball. The ball has an acceleration of 20m/s2. How much was the force that Johnny used?
Answer:
The answer is 40 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 2 × 20
We have the final answer as
40 NHope this helps you
Answer: 40N
Explanation:
Force = mass × acceleration
20 x 2 = force
20 x 2 is 40
Answer 40 N
NOT 40J
branches of sicence
Answer:
Natural science can be divided into two main branches
Explanation:
life science and physical science. Life science is alternatively known as biology, and physical science is subdivided into branches: physics, chemistry, astronomy and Earth science.
Answer:
Astronomy
Biology
Geology
Chemistry
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Calculate the density of the rock if its mass is 360 g.
Answer:
12.0 g/mL
Explanation:
From the question given above, the following data were obtained:
Mass of Rock = 360 g
Volume of water = 150 mL
Volume of water + Rock = 180 mL
Density of Rock =?
Next, we shall determine the volume of the rock. This can be obtained as follow:
Volume of water = 150 mL
Volume of water + Rock = 180 mL
Volume of Rock =?
Volume of Rock = (Volume of water + Rock) – (Volume of water)
Volume of Rock = 180 – 150
Volume of Rock = 30 mL
Finally, we shall determine the density of the rock as illustrated below:
Mass of Rock = 360 g
Volume of Rock = 30 mL
Density of Rock =?
Density = mass /volume
Density of Rock = 360 / 30
Density of Rock = 12.0 g/mL
Thus, the density of the rock is 12.0 g/mL
What is the mole fraction of each component if 3.9 g of benzene (C6H6) is dissolved in 4.6 g of toluene (C7H8)
Answer:
Step 1 of 6
(a)
The mass of benzene is  , so calculate the moles of benzene as follows:

The mass of toluene is, so calculate the moles of toluene as follows:

Now, calculate the mole fraction as follows:


Therefore, the mole fraction of benzene and toluene is  and  respectively.
Step 2 of 6
(b)
The formula to calculate the partial pressure is as follows:

Here,  is the partial pressure of benzene,  is the vapour pressure of pure benzene and  is the mole fraction of benzene.
Vapour pressure of pure benzene at  is.
Substitute the values in the equation as follows:

Therefore, the partial pressure is  .
Step 3 of 6
(c)
Vapor pressure of the solution at 1 atm is  .
When the total pressure of the vapour pressure of the mixture is  at a temperature, then, the solution boils. It corresponds to the boiling point of the solution.
Calculate the total pressure of the solution at  as follows:

Since, the total pressure is less than the atmospheric pressure, the solution will not boil at  .
Calculate the total pressure of the solution at  as follows:

Since, the total pressure is greater than the atmospheric pressure, the solution will boil at  .
Therefore, the boiling point of the solution is  .
Step 4 of 6
(d)
Mole fraction of benzene at  is calculated as follows:

Mole fraction of toluene at  is calculated as follows:

Therefore, the mole fractions of benzene and toluene are  and  respectively.
Step 5 of 6
(e)
Vapor pressure of benzene at  is  .
Partial pressure of benzene is calculated as follows:

Vapor pressure of toluene at  is  .
Partial pressure of toluene is calculated as follows:

Step 6 of 6
Weight composition of the vapour that is in equilibrium with the solution is calculated as follows:

Weight composition of the vapour that is in equilibrium with the solution is calculated as follows:

Explanation:
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Please i really need help
it's due today
Answer:
coke and mentos are basically just a small scale replica
Explanation:
Given the reaction _K(s) +_ Cl2(g) → _KCl(s) what is the amount of K, in grams, needed to completely react with 2 moles of Cl2(g)?
Answer:
156.4g K
Explanation:
I'm not sure if it is correct but I think it should be this
What do we know so far?: 2K + 1Cl2 -> 2KCl, 2 mol of Cl2
What are we looking for?: #g of K
What is the ratio of K to Cl2?: 2:1
Set up equation: 2molCl2 x [tex]\frac{2mol K}{1 mol Cl2}[/tex]
Cancel unwanted units: 2 x [tex]\frac{2mol K}{1}[/tex]
Answer we got: 2 x 2mol K = 4mol K
Converting moles to grams: 4 x 39.1 (molar mass of K) = 156.4g K
The size of the orbital is determined by the nn The size of the orbital is determined by the ______ quantum number, so the size of the orbital _______ as this value increases. Therefore, an electron in a _______ orbital is closer to the nucleus than is an electron in a ________ orbital. quantum number, so the size of the orbital The size of the orbital is determined by the _______ quantum number, so the size of the orbital ________ as this value increases. Therefore, an electron in a _______ orbital is closer to the nucleus than is an electron in a ________ orbital. as this value increases. Therefore, an electron in a The size of the orbital is determined by the ________ quantum number, so the size of the orbital _________ as this value increases. Therefore, an electron in a ________ orbital is closer to the nucleus than is an electron in a _________ orbital. orbital is closer to the nucleus than is an electron in a The size of the orbital is determined by the _______quantum number, so the size of the orbital ________ as this value increases. Therefore, an electron in a ________ orbital is closer to the nucleus than is an electron in a ________ orbital. orbital.
Answer:
Explanation:
The size of the orbital is determined by the principal quantum number (n), so the size of the orbital increases as this value increases. Therefore, an electron in a 1 orbital is closer to the nucleus than is an electron in a 2 orbital.
An atomic orbital can be thought of as the wave function of an electron in an atom. The Principal Quantum Number (n) is one of the quantum numbers that are required to describe the distribution of electrons in atoms. This quantum number has positive integral values such as 1, 2, 3 and so on. It also relates to the mean distance of the electron from the nucleus in a given orbital. The larger the quantum number, the greater the mean distance of an electron in that orbital from the nucleus, therefore the orbital will be larger.
Which of the following is a chemical change? A. soil drying as water evaporates B. a rock eroding as the wind removes particles from it C. a solution of salt water being diluted as water is added to it D. silver tarnishing as the silver metal reacts with sulfur
Answer:
Its D
Explanation:
I took the quiz
Answer:
D
Explanation:
IT IS REACTING
Ammonia (NH3) is the active cleaning ingredient in Windex and is also the main contributor to the odor of stale cat urine. Ammonia has a ΔH°vap of 23.35 kJ/mol and a ΔS°vap of 97.43 J/mol·K. What is the normal boiling point of ammonia
Answer:
[tex]T_b=239.7K=-33.49\°C[/tex]
Explanation:
Hello!
In this case, since the relationship between entropy and enthalpy for any process is defined below:
[tex]S=\frac{H}{T}[/tex]
For the vaporization of ammonia or any liquid, we can write:
[tex]\Delta S_{vap}=\frac{\Delta H_{vap}}{T_{vap}}[/tex]
In such a way, solving the temperature of vaporization, or boiling point, we have:
[tex]T_{vap}=\frac{\Delta H_{vap}}{\Delta S_{vap}}[/tex]
Plugging in the given enthalpy and entropy of vaporization we obtain:
[tex]T_{vap}=T_b=\frac{23350\frac{J}{mol} }{97.43\frac{J}{mol*K}} \\\\T_b=239.7K=-33.49\°C[/tex]
Best regards!
From the information provided in the question, the boiling point of ammonia is 240 K.
Entropy is the degree of disorderliness in a system. The entropy of a system can be obtained using the relation;
ΔS°vap = ΔH°vap /T
Now;
ΔH°vap = 23.35 kJ/mol
ΔS°vap = 97.43 J/mol·K
T = ?
Making T the subject of the formula and substituting values;
T = ΔH°vap /ΔS°vap
T = 23.35 × 10^3J/mol/97.43 J/mol·K
T = 240 K
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element that is the "best" at removing electrons from other atoms.
Answer:
Fluorine
Explanation:
Fluorine is the "best" at removing electrons because it has 5 electrons on its second shell. The 5 electrons are really close and are trying to drag in another electron to complete the shell and have all 6 electrons to complete the valence shell.
2. Which of the following would produce a precipitate when mixed water (H20)?
A) HNO3
B) Br2
C) BaS
D) PbBr2
3.Given that the reaction below is a precipitation reaction, what is the missing symbol?
Li2CO3 (aq) + BaS (aq) - > LiOH (aq) + BaCo3 (?)
Answer: #2 : s, solid & #3 : PbBr2
Explanation:
In the reaction [tex]\rm Li_2CO_3 (aq) + BaS (aq)\rightarrow LiOH (aq) + BaCo_3 (?)[/tex] the missing symbol is s . The PbBr₂ will produce a precipitate when mixed water. Hence option D is correct.
What is chemical reaction?Chemical reaction is defined as a procedure that involves changing a substance's molecular or ionic structure, as opposed to changing its physical shape or undergoing a nuclear reaction. When atoms establish or break chemical bonds, chemical reaction take place. Reactants are the substances that begin a chemical reaction, while products are the compounds that are created as a result of the reaction.
Precipitation is defined as the mechanism by which water vapor in the atmosphere condenses and descends to the ground under the pull of gravity. Water vapor in the clouds condenses into increasing-sized droplets of water, forming precipitation. To replenish the water on the earth, precipitation is required. This world would be a vast desert if it didn't rain. Within an estuary, water level and water quality are impacted by the frequency and length of precipitation events.
Thus, in the reaction [tex]\rm Li_2CO_3 (aq) + BaS (aq)\rightarrow LiOH (aq) + BaCo_3 (?)[/tex] the missing symbol is s . The PbBr₂ will produce a precipitate when mixed water. Hence option D is correct.
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Which of the following accurately pairs the part of an atom to its charge? A. Proton—no charge B. Neutron—positive charge C. Electron—negative charge D. Electron—no charge
Answer:
I think it's c but I'm not sure
Answer: C
Explanation:
By what mechanism does cyclohexanol react when treated in concentrated sulfuric acid/phosphoric acid and what compound results?
Answer:
The mechanism is E1 and the product is cyclohexene
Explanation:
Attached to this answer is an image of the reaction mechanism of the reaction between cyclohexanol and concentrated sulfuric acid/phosphoric acid. The acid (H3O^+) acts as catalyst.
We can see that the first step in the mechanism is the protonation of the -OH group of the alcohol. This is followed by loss of water molecule which is a good leaving group.
The water now acts as a Lewis base by abstracting a proton from the substrate, forming cyclohexene and regenerating the acid catalyst.
what looks attractive on guys
Answer: for me everything ig
Explanation:
How many atoms are in this given equation 6Mn3C2
Answer:
There are three atoms in the equation
The specific rotation of (S)-2- butanol is + 13.5. If 1.00 g is dissolved in 10.0 mL of ethanol and placed in a sample cell with a length of 1.00 dm, what observed rotation do you expect?
Answer:
-1.35 degree
Explanation:
Given the specific rotation of (S)-2-butanol = +13.5 degree
So, the specific rotation of its enantiomer (R)-2-butanol = -13.5 degree
Now the optical rotation of a pure liquid is given by
[tex]$\theta = [\alpha]_\lambda ^t.l.d$[/tex]
Here, [tex]$\theta$[/tex] = the optical rotation
[tex]$[\alpha]_\lambda^t$[/tex] = specific rotation at temperature 't' and wave length 'λ'
= -13.5 degree
l = optical path length
= 1 dm
d = density
= 1/10
Therefore,
[tex]$\theta = -13.5 \times 1 \times \frac{1}{10}$[/tex]
= -1.35 degree
While setting up a beaker to boil a solution on a hot plate, you notice that the stirring is erratic and unstable. What should you do to stabilize the stirring solution? a. Clamp the beaker in place at the edge of the hot plate. b. Move the beaker to the center of the hot plate. c. Turn down the stirring speed. d. Completely turn off the stirring function.
Answer:
B. Move the beaker to the center of the hot plate
Explanation:
The erratic and unstable stirring might be caused by the beaker not being properly balanced on the hot place, there by distorting the the center of gravity of the stirring motion.
In properly positioning the stirrer to the hot plate, the magnetic rod is positioned to the center of the fluid, allowing for a more fluid and even effective stirring.
I hope this was helpful.
The temperature at which a particular liquid becomes a gas
5 points
A melting point
B boiling point
C freezing point
D sublimation point
5 points
a substance made of at least two atoms that are chemically combined
Apure substance
B element
C compound
D mixture
Answer:
A: melting point and the other one is i think element
The volume of a gas decreases to half of its original volume, but the gas maintains the same
number of moles and temperature. According to the ideal gas law, what will most likely
happen to the pressure?
A. It will double.
B. It will decrease.
C. It will increase slightly.
D. It will remain the same.
Answer:
c
Explanation:
it will slightly increase
Answer:
A
It will double
What type of temperatures and moisture content does Marine time Tropical air have?
Group of answer choices
Cold Temps/ Moist Air
Warm Temps/ Dry Air
Cold Temps/ Dry Air
Warm Temps/ Moist Air
Answer:
D: Warm Temps/ Moist Air
Explanation:
Tropical places usulay have warm mosit air
Maritime Tropical air is associated with warm temperatures and moist air.
Maritime Tropical (mT) air is a type of air mass that forms over warm tropical or subtropical ocean regions. It acquires its characteristics from the ocean's influence, particularly its warm temperatures and high moisture content.
Warm Temperatures: Maritime Tropical air masses originate from regions near the equator or subtropics, where solar radiation is intense and consistently high. As a result, these air masses are typically warm, with temperatures ranging from mild to hot.
The term "Maritime" refers to air masses that have originated from over the ocean, which generally have higher moisture content due to evaporation from the ocean surface. The term "Tropical" indicates that the air mass originates from or near tropical regions, where warm temperatures are prevalent.
Therefore, the correct answer is: Warm Temps/ Moist Air.
Learn more about Maritime Tropical from the link given below.
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What does animals exhale?
Answer:
Carbon dioxide
Explanation:
Humans are animals and we exhale carbon dioxide
what is the president for 2020
Answer:
joe biden
Explanation:
It was DONALD TRUMP :) But Joe Biden got elected :(
The bond lengths of the X-H bonds in CH4, SiH4, and SnH4 are 1.09, 1.48, and 1.71 Å, respectively. Estimate the length of the Ge-H bond in GeH4. Which of these four hydrides has the weakest X-H bond?Estimated Ge-H bond length =________________ ÅWeakest X-H bond in ________________
Answer:
what
Explanation:what
The autoignition of both ethanol and octane occurs at 363 oC. Which gas sample contains the gas molecules that have a greater average kinetic energy
Answer:
See explanation
Explanation:
At the same temperature, the average kinetic energy of gases depends on the molecular mass of the gas. Hence, given a particular temperature, lighter molecules travel faster on the average than heavier molecules.
Considering ethanol and octane, The molar mass of ethanol is 46.07 g/mol while the molar mass of octane is 114.23 g/mol. Hence, ethanol has a greater average kinetic energy than octane at the same temperature.
When a sample of liquid is heated, its thermal energy _______.
Answer:
Entropy.
Explanation:
I really hope this is right! sorry if its wrong
When a sample of liquid is heated, its thermal energy: increases.
Thermal energy can be defined as the energy possessed by an object due to the movement of its particles.
Basically, the temperature of an object or system is highly dependent on thermal energy.
Hence, temperature is directly proportional to thermal energy.
Additionally, as the temperature of an object increases due to the application of heat, the thermal energy of the object increases.
In conclusion, thermal energy increases when a sample of liquid is heated.
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10 things you should never do while making a measurement in chemistry
Answer:
Measure at the top of the meniscus
Hold the container (it is unsteady)
Explanation:
I'm really, really, sorry. I took chemistry in 6th grade and I'm in 8th, and I don't remember the entire list. This is all I could think of.
A solution of hydrochloric acid of unknown concentration was titrated with 0.16 M NaOH. If a 350-mL sample of the HCl solution required exactly 17 mL of the NaOH solution to reach the equivalence point, what was the pH of the HCl solution?
Answer:
The correct answer is 2.1
Explanation:
The neutralization reaction involved in the titration is between a strong acid (HCl) and a strong base (NaOH), as follows:
HCl + NaOH → NaCl + H₂O
According to this, 1 equivalent of HCl reacts with 1 equivalent of NaOH. The equivalence point is the point at which the amount of NaOH added reacted completely with the amount of HCl.
moles of acid = moles of base
moles HCl = moles NaOH
Ca x Va = Cb x Vb
Ca = (Cb x Vb)/Va = (0.16 M x 17 mL)/(350 mL) = 7.8 x 10⁻³ M
Since HCl is a strong acid, we calculate the pH of the solution directly from the concentration of acid:
[H⁺]= Ca = 7.8 x 10⁻³ M
pH = -log [H⁺] = -log (7.8 x 10⁻³ M) = 2.11
Therefore, the pH of the HCl solution is 2.1
what is the the correct equation for water gas
Answer:
Water-gas A mixture of carbon monoxide (CO) and hydrogen (H2) produced by passing steam over red-hot coke using the endothermic reaction C + H2O → CO + H2.
Which statement describes how phase changes
can be diagrammed as a substance is heated?
The phase is on the y-axis and thew
temperature is on the x-axis.
The temperature is on the y-axis and the
phase is on the x-axis.
The time is on the y-axis and the temperature
is on the x-axis.
The temperature is on the y-axis and the time
is on the x-axis
Answer: D
Explanation:
On edge
Answer:
D
Explanation:
just did it on Ed