Answer:
26
Explanation:
The number of electrons and protons are equal.
QUESTION 3
Identify the number that has 3 significant figures.
O A. 100
OB. 12.0
O C. 120
OD. 123.00
Answer:
D
Explanation:
___C3H8 + ___O2 --> ___H2O + ___CO2
Answer:
C3H8 + 5O2 ‐‐‐‐‐‐‐‐> 4H2O + 3CO2
Why is your body going through physical and chemical changes?
Answer:
Physical and chemical changes can occur almost everywhere, even in our bodies! Food must be broken down into a form that our cells can use. When we eat, our bodies physically break down food into small pieces. Our bodies also chemically break down those small pieces of food into tiny organic molecules.
Explanation:
Mg(s)+2HCl(aq) → MgCl2(aq)+H2(g)
In an experiment, a student places a small piece of pure Mg(s) into a beaker containing 250.mL of 6.44MHCl(aq) . A reaction occurs, as represented by the equation above.
(a) Write the balanced net ionic equation for the reaction between Mg(s) and HCl(aq) .
Answer:
[tex]Mg(s)+2H^+(aq)\rightarrow Mg^{2+}(aq)+H_2(g)[/tex]
Explanation:
Hello!
In this case, since the writing of a net ionic equation first implies writing the complete molecular equation:
[tex]Mg(s)+2HCl(aq) \rightarrow MgCl_2(aq)+H_2(g)[/tex]
We can see that HCl and MgCl2 are ionized because they are aqueous, thus we write:
[tex]Mg(s)+2H^+(aq)+2Cl^-(aq) \rightarrow Mg^{2+}(aq)+2Cl^-(aq)+H_2(g)[/tex]
In such a way, we can cancel out the chloride ions as they are the spectator ones to obtain the net ionic one:
[tex]Mg(s)+2H^+(aq)\rightarrow Mg^{2+}(aq)+H_2(g)[/tex]
Best regards!
The concentration of hydrogen peroxide solution can be determined by
titration with acidified potassium manganate(VII) solution. In this reaction
hydrogen peroxide is oxidised to oxygen gas. A 5.0 cm sample of hydrogen
peroxide solution was added to a volumetric flask and made to 250 cm
of the aqueous solution. A 25.0 cm sample of this solution was acidified
and reacted completely with 24 35 em of 0.0187 mol dm potassium
manganate(VII) solution
(ay Write a balanced equation for the reaction between acidified KMnO
solution and H.O.
(b) Calculate the concentration of the original H,O, solution in mol dm
The question is incomplete, the complete reaction equation is;
The concentration of a hydrogen peroxide solution can be determined by titration
with acidified potassium manganate(VII) solution. In this reaction the hydrogen
peroxide is oxidised to oxygen gas.
A 5.00 cm3 sample of the hydrogen peroxide solution was added to a volumetric flask
and made up to 250 cm3 of aqueous solution. A 25.0 cm3 sample of this diluted
solution was acidified and reacted completely with 24.35 cm3 of 0.0187 mol dm–3
potassium manganate(VII) solution.
Write an equation for the reaction between acidified potassium manganate(VII)
solution and hydrogen peroxide.
Use this equation and the results given to calculate a value for the concentration,
in mol dm–3, of the original hydrogen peroxide solution.
(If you have been unable to write an equation for this reaction you may assume that
3 mol of KMnO4 react with 7 mol of H2O2. This is not the correct reacting ratio.)
Answer:
2.275 M
Explanation:
The equation of the reaction is;
2 MnO4^-(aq) + 16 H^+(aq) + 5H2O2(aq) -------> 2Mn^+(aq) + 10H^+ (aq) + 8H2O(l)
Let;
CA= concentration of MnO4^- = 0.0187 mol dm–3
CB = concentration of H2O2 = ?
VA = volume of MnO4^- = 24.35 cm3
VB = volume of H2O2 = 25.0 cm3
NA = number of moles of MnO4^- = 2
NB = number of moles of H2O2 = 5
From;
CAVA/CBVB = NA/NB
CAVANB = CBVBNA
CB = CAVANB/VBNA
CB = 0.0187 * 24.35 * 5/25.0 * 2
CB = 0.0455 M
Since
C1V1 = C2V2
C1 = initial concentration of H2O2 solution = ?
V1 = initial volume of H2O2 solution = 5.0 cm3
C2 = final concentration of H2O2 solution= 0.0455 M
V2 = final volume of H2O2 solution = 250 cm3
C1 = C2V2/V1
C1 = 0.0455 * 250/5
C1 = 2.275 M
A compound is found to contain 26.73 % phosphorus, 12.09 % nitrogen, and 61.18 % chlorine by mass. What is the empirical formula for this compound
Answer:
[tex]PNCl_2[/tex]
Explanation:
Hello!
In this case, when determining empirical formulas by knowing the by-mass percent, we first must assume the percentages as masses so we can compute the moles of each element:
[tex]n_P=\frac{26.73g}{30.97g/mol}=0.863mol\\\\n_N=\frac{12.09g}{14.01g/mol}=0.863mol\\\\n_C_l=\frac{61.18g}{35.45g/mol}=1.726mol[/tex]
Now, for the determination of the subscript of each element in the empirical formula, we divide the moles by the fewest moles (P or N):
[tex]P=\frac{0.863mol}{0.863mol}=1\\\\N= \frac{0.863mol}{0.863mol}=1\\\\Cl=\frac{1.726mol}{0.863mol}2[/tex]
Thus, the empirical formula is:
[tex]PNCl_2[/tex]
Regards!
How many atoms are in .938 moles of CO2?
Answer: 1.695x10^24 atoms
Explanation: 0.938 moles CO2 = 0.938xavogadro number molecules CO2, so number of atoms = 3x0.938x6.02214076x10^23 = 1.695x10^24
Which of the following is NOT an advantage of a wireless network? convenience reliability security speed
Answer:
Security
Explanation:
A wireless network consists of good connection with fast speed, convenience, and reliability. Security is a major problem with wireless connection as someone can get your information by joining the same connection as you.
How many electrons will the lithium atom give up to become stable?
a. 1
b. 2
c. 3
d. 4
Answer: 2
Explanation: that’s the answer for the quiz
Elements in the same group of the periodic table have the same number of
Answer:
valence electrons
The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements. Every element in the first column (group one) has one electron in its outer shell.
If a piece of cadmium with a mass of 37.60 g and a temperature of 100.0 oC is dropped into 25.00 cc of water at 23.0 oC, what will be the final temperature of the system
Answer:
[tex]T_{eq}=28.9\°C[/tex]
Explanation:
Hello!
In this case, since it is observed that hot cadmium is placed in cold water, we can infer that the heat released due to the cooling of cadmium is gained by the water and therefore we can write:
[tex]Q_{Cd}+Q_{W}=0[/tex]
Thus, we insert mass, specific heat and temperatures to obtain:
[tex]m_{Cd}C_{Cd}(T_{eq}-T_{Cd})+m_{W}C_{W}(T_{eq}-T_{W})=0[/tex]
In such a way, since the specific heat of cadmium and water are respectively 0.232 and 4.184 J/(g °C), we can solve for the equilibrium temperature (the final one) as shown below:
[tex]T_{eq}=\frac{m_{Cd}C_{Cd}T_{Cd}+m_{W}C_{W}T_{W}}{m_{Cd}C_{Cd}+m_{W}C_{W}}[/tex]
Now, we plug in to obtain:
[tex]T_{eq}=\frac{37.60g*0.232\frac{J}{g\°C}*100.00\°C+25.00g*4.184\frac{J}{g\°C}*23.0\°C}{37.60g*0.232\frac{J}{g\°C}+25.00g*4.184\frac{J}{g\°C}}\\\\T_{eq}=28.9\°C[/tex]
NOTE: since the density of water is 1g/cc, we infer that 25.00 cc equals 25.00 g.
Best regards!
Which of these factors are biotic? (SELECT ALL THAT APPLY.)
animals
light
minerals
water
plants
Answer:
plants
Explanation:
because it produces ( i am a third grade student and don't know if it is right or not)
25) Organize the following in the most likely order of increasing melting point.
NH3 (polar)
CH4 (nonpolar)
CH10 (nonpolar)
HBr (polar)
A) NH3 < HBr < CH4 < C4H10
B) CH4 < C4H10 < HBr < NH3
NH3
CH4 = HBr < 4H10 < NH3
D)
Answer:b
Explanation:
Right
A root is an example of a/an-
A: tissue
B: cell type
C:organ
D:organism
Answer: D an organism
Explanation:
Aton Van Leeuwenhoek was the first scientist to discover prokaryotic organisms. These single-celled organisms lack a nucleus and other membrane bound organelles but do have a cell membrane, DNA, and even a cell wall. Choice one of the answer. A. All known living things are made up of one or more cells. B. All living cells come from pre-existing cells by division. C. A cell is the fundamental unit of structure and function in all living organisms. D. No answer text provided
Answer: a
Explanation:
Which equation could be used to solve for the average speed of a car that travels 90m in 20 seconds?
Answer:
Vav=d/t
Explanation:
Because the question already gave d=90m and t=20s. Because the car is the thing that can not travel the same distances at the same times.So the equation is V[tex]\\_{av}[/tex]=[tex]\frac{d}{t} \\[/tex]
GIVING OUT BRAINLIEST!!!!!!!!!
Which substance has the lowest specific heat?
O Beach sand
O
Beach water
O Ice
Pool water
What is the temperature if 2L of 3moles HCl react with 2atm?
Answer:
[tex]T=16K=-256.8\°C[/tex]
Explanation:
Hello!
In this case, according to the gas laws, we would be able to assume HCl can be modeled as an ideal gas for this calculation purpose; in such a way, we use the following equation to compute the temperature:
[tex]PV=nRT\\\\T=\frac{PV}{nR}[/tex]
In such a way, we plug in moles, volume and pressure to obtain:
[tex]T=\frac{2atm*2L}{3mol*0.08206\frac{atm*L}{mol*K}}\\\\T=16K=-256.8\°C[/tex]
Best regards!
How would kinetic energy of the dominoes be affected if the first domino did not hit the second one?(((20 points)))
Answer:
Not affected.
Explanation:
Kinetic energy of the dominoes not affected if the first domino did not hit the second one because no kinetic energy is lost due to no collision. If the first domino hit the second one, its kinetic energy decreases and changes in other form of energy such as heat and sound energy etc. But when there is no collision occur, then there is no change in the kinetic energy of dominoes.
what is fractional distillation what is fractional distillation explain it with the help of an activity
Answer:
Fractional distillation is a method for separating liquids with different boiling points. For example, liquid ethanol can be separated from a mixture of ethanol and water by fractional distillation. ... The boiling point of ethanol is 78°C and the boiling point of water is 100°C.
How do we use positive and negative signs to communicate the direction of a vector
Answer:
Two vectors are equal if they have the same magnitude and the same direction. Just like scalars which can have positive or negative values, vectors can also be positive or negative. A negative vector is a vector which points in the direction opposite to the reference positive direction.
What are the outcomes of the ice cap melting? Choose all that apply.
1. Light cannot be reflected back to the atmosphere
2. Sea level rises
3. Absorption of solar radiation leads to increase in ocean temperature
4. Ocean remains unaffected
Answer:
2. sea level rises sorry if it's wrong
Prokaryotic is an example of a/an-
A:tissue
B:cell type
C:organ
D:organism
Answer:
B. Cell Type
Explanation:
that is the answer i believe
Answer:
option b- cell type
Explanation:
almost absolutely positive
What is one reason a fuse may blow out? NEED HELP NOW
Answer:
Too high voltage which can't be held by the fuse
What element contains 8 valence electrons and tends not to react with other elements?
Answer:
C. Oxygen
Explanation:
Oxygen has 8 electrons and doesn't react with fluorine noble gases
Please help!!! The person who gets it right gets brainlist
Answer:B because all of the atoms exploded AND GRAVITY WAS CREATED AND forced molecules together (God caused it btw)
Explanation:The BIBLE
Red light waves have a longer wavelength than green light waves. What can you conclude from this? PLEASE HELP IF YOU WANT ME TO GIVE YOU BRAINLEIST AND LIKE YOUR COMMENT!!
A. Green light waves have the same frequency as red ones.
B. Green light waves have a higher frequency than red ones.
C. Green light waves have a smaller frequency than red ones.
A longer wavelength means that it has a small frequency, so B.
In this case, red light has the longest wavelength on the spectrum. Anything past red will always have a smaller wavelength and it will always shrink until reaching violet.
Answer:
B
Explanation:
Higher frequencies have smaller wavelengths
Smaller frequencies have higher wavelengths
HELP??????..... Which type of semiconductor is created by doping with atoms that contain more valence electrons than the semiconductor material?
A. Intrinsic and p-type
B. Intrinsic
C. N-type
D. P-type
Answer:
Explanation:
N - type semi conductor
Which of the following is the conjugate base of HSO3-?
A. H2SO3
B. SO2
C. S032
D. HSO3+
An acid and a base which differ from each other by a proton are said to form a conjugate pair. The conjugate base of HSO₃⁻ is SO₃²⁻. The correct option is C.
What is a conjugate base?The entity produced when an acid gives up a proton has a tendency to regain the proton and hence it behaves as a base. It is called the conjugate base of the parent acid.
The entity produced when a base accepts a proton has a tendency to donate the proton and hence behaves as an acid. It is called the conjugate acid of the parent base.
Sulfur dioxide dissolved in water gives sulfurous acid H₂SO₃. The conjugate base of this material contains one proton less i.e, HSO₃⁻ and the conjugate base of the substance bisulfite is SO₃²⁻which is sulfite ion.
Thus the correct option is C.
To know more about conjugate base, visit;
https://brainly.com/question/30225100
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PLEASE HELP WILL MARK BRAINLIEST
how does the container with the plastic wrap stimulate carbon dioxide in the atmosphere?
Answer:
The Earth’s greenhouse effect is a natural consequence of the chemical makeup of its atmosphere. If it
were not for the greenhouse effect, life as we know it could not exist on Earth: it would be too cold. Our
atmosphere is made mostly of nitrogen and oxygen, but also contains several other gases. These include
carbon dioxide, methane, nitrous oxide, water vapor and ozone, which are known as greenhouse gases.
Greenhouse gases are released naturally through geologic processes and the metabolic activity of living
things. However, there is an ongoing debate over human effects on Earth’s global climate. Human industrial activity on the planet has increased the quantities of greenhouse gases through agriculture, manufacturing, power generation, and engines used for transportation. Key questions include: Is the average temperature of Earth increasing? Does the presence of human beings contribute to global warming? If the temperature of Earth does become warmer, how will it affect us?
Explanation: