Answer:
[tex]B_3H_6N_3[/tex]
Explanation:
Hello there!
In this case, since the mass percentages in a compound which is wanted to know the molecular formula, can be assumed to be the masses, we first need to compute the moles they have in the formula unit:
[tex]n_B=40.29gB*\frac{1molB}{10.811gB} =3.73molB\\\\n_H=7.51gH*\frac{1molH}{1.01gH} =7.44molH\\\\n_N=52.20gN*\frac{1molN}{14.01gN} =3.73molN[/tex]
Next, we divide each moles by the fewest ones (3.73 mol) in order to find the subscript in the empirical formula first:
[tex]B:\frac{3.73}{3.73}=1 \\\\H:\frac{7.44}{3.73}=2\\\\N:\frac{3.73}{3.73}=1[/tex]
Then, the empirical formula is BH2N whose molar mass is 26.83 g/mol, so the ratio of molecular to empirical is 80.50/26.83=3; therefore, the molecular formula is three times the empirical one:
[tex]B_3H_6N_3[/tex]
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what does dry ashing mean
which of the following human activities are not related to an increase in global temperature
A 10.0 mL sample of H2SO4 was exactly neutralized by 23.5 mL of 1.00 M KOH. Calculate the molarity of the acid. H2SO4(aq) + KOH(aq) —> K2SO4(aq) + H2O(l)
Answer:
1.175 M
Explanation:
The balanced reaction is:
H₂SO₄(aq) + 2KOH(aq) —> K₂SO₄(aq) + 2H₂O(l)First we calculate how many moles of KOH reacted, using the given concentration and volume:
1.00 M * 23.5 mL = 23.5 mmol KOHThen we convert moles of KOH to moles of H₂SO₄, using the stoichiometric coefficients of the balanced reaction:
23.5 mmol KOH * [tex]\frac{1molH_2SO_4}{2molKOH}[/tex] = 11.75 mmol H₂SO₄Finally we calculate the molarity of the acid:
11.75 mmol H₂SO₄ / 10.0 mL = 1.175 MWhich of the following has had the most negative effect on Earth's ecosystems?
A. establishment of air pollution standards.
B. increase in human population
C. recycling glass, plastic, and metals
D. use of natural predators to control pest insects.
Answer:
B
Explanation:
humans are evil, done a lot of negative effects on ecosystem.
6621.5 kJ of heat is required to convert a 20.5 g sample of
aluminum from the solid to liquid phase. What is the heat of
fusion of aluminum in kJ/g?
kJ/g
Answer:
323 kJ/g
Explanation:
ck-12 said it was correct
Calculate the number of nickel atoms in a 5-cent coin of mass 0.942g if it was made of an alloy consisting of 75% copper and 25% nickel.
Answer:
2.41x10²¹ atoms
Explanation:
First we calculate the mass of nickel in the coin, using the given mass and percent composition:
0.942 g * 25/100 = 0.2355 g NiThen we convert 0.2355 grams of nickel to moles, using its molar mass:
0.2355 g Ni ÷ 58.69 g/mol = 0.004 molFinally we convert moles into number of atoms, using Avogadro's number:
0.004 mol * 6.023x10²³ atoms/mol = 2.41x10²¹ atomsWilliam Rankine coined this energy from
A. Mechanical energy
B. Kinetic energy
C. Potential Energy
D. Total energy
E. Chemical Energy
Answer:
C.Potential Energy
Explanation:
Help me pls I put 49 point( every single point that I have) pls help me
Answer:
see below
Explanation:
1) chem rxn compound molecule covalent ions ionic
2) 2 hydrogen one oxygen H2O covalent
3) is always liq
Can someone help me I am stuck on this question it would mean the world if u helped me =) have a nice day!
Where is the arctic tundra biome found?
Use this website to answer the question: https://thewildclassroom.com/biomes/artictundra-2/
Question 2 options:
Almost entirely in the Northern Hemisphere, from 60 to 70 degrees latitude North.
In tropical and subtropical latitudes
In high altitudes
Within tropical and subtropical latitudes
Answer:
In high altitudes
Explanation:
hope it helps you
The artic tundra biome is found in high altitudes.
What is arctic tundra biome?Artic tundra biome is the northernmost biome, which covers the land of the arctics with the ice caps.
Climate of this Artic tundra biome is almost cold means the temperature in winter season of this region is about -34 degree celsius and temperature in summer season of this region is about 3 - 12 degree celsius. And it observed generalyy on the northen side.
Hence correct option is (C).
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A gas with a volume of 4.0 L at a pressure of 0.9 atm is allowed to expand until the pressure drops to 0.20 atm. What is the new volume?
Answer: 25
Explanation:
The new volume will be 18 L
What is volume?The volume of a dry gas of a given mass was inversely proportional to its pressure at constant temperature, according to Boyle's law. At moderate pressures and temperatures, most gases behave like ideal gases.
Calculation of new volume is shown as below:
The new volume of can be calculated by using Boyle's law.
[tex]P_{1} V_{1} = P_{2} V_{2}[/tex]
It is given that, [tex]P_{1}[/tex] = 0.9 atm. [tex]V_{1}[/tex] = 4 L, [tex]P_{2}[/tex] = 0.20 atm
Now, put the values of given data in above equation.
[tex]V_{2}[/tex] = [tex]P_{1}V_{1}[/tex] / [tex]P_{2}[/tex].
[tex]V_{2}[/tex] = (0.9) ×4 / 0.20
= 3.6 / 0.20
= 18 L
therefore, the new volume will be 18 L.
To know more about volume.
https://brainly.com/question/2098026.
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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
At which point on the roller coaster will the car have the greatest amount of Kinetic energy?
When planning a simple experiment, what does it mean to “test one variable”?
a During the experiment, the scientist keeps the control the same but changes many other elements he or she is testing.
b During the experiment, the scientist has only one element, or variable, that is changed to test the hypothesis.
c The scientist can only use simple language and materials when planning the one variable to be tested.
d The scientist plans and performs just one science experiment a day to test one variable.
Answer:
I believe the answer is "b". "During the experiment, the scientist has only one element, or variable, that is changed to test the hypothesis."
Explanation:
I remember from last year but I'm not totally sure. Good luck!
The experimental setup has been the design that includes the experimental and the control group. during the experiment, only one variable is changed to test the hypothesis. Thus, option b is correct.
What is experimental design?The experiment design includes the testing of the hypothesis to solve the problem and reach the solution through the analysis of the observations. It has been the setup that includes the test and the control group that involves the dependent, independent, and controlled variables.
Testing one variable in the experimental designs means changing one of the elements of the experience to prove the reliability of the hypothesis. This variable is the factor that alters and affects the other factors of the experiment and leads to a cause and effect.
The result of the effect of the hypothesis proves the testability of the experiment and provides solutions to the research question. This further leads to the formulation of the law and theory.
Therefore, option A. testing one variable involves proving the hypothesis.
Learn more about experimental design, here:
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Predict the products for the reaction shown in the picture.
Fe(s) + CuCrO4(aq) —>
Answer:
After checking many websites as well
I haven't seen any answer for this reaction
While I found answers or other reactions
Therefore I think this reaction cannot occur
Please mark my answer as brainliest if you feel I helped you in any way :)
Anyone know the answer
Answer:
b
Explanation:
i know
cosity a letter to our mother
who is in lagos Nigeria telling
her about the
the problem you are
facing
in the school and at
home and suggest solution to
you pproblem
Basic Stoichiometry
Part 1: Mole ←→ Mass Conversions
Choose 2: Convert the following number of moles of chemical into its mass in grams.
1. 0.436 moles of (NH4)Cl = ______g
2. 0.50 moles of Ca(NO3)2 = ______g
Choose 2: Convert the following masses into their corresponding number of moles.
3. 23.5 g of NaCl = ______moles
4. 79.9 g of KMnO4 =______moles
5) The combustion of a sample of butane, C4H10 (lighter fluid), produced 2.46 grams of water.
Answer:
1. 23.3 g
2. 82 g
3. 0.402 mol
4. 0.506 mol
Explanation:
We can convert moles (n) to mass (m) using the following expressions that include the molar mass (M).
n = m/M
m = n × M
1. The molar mass of NH₄Cl is 53.49 g/mol.
m = 0.436 mol × 53.49 g/mol = 23.3 g
2. The molar mass of Ca(NO₃)₂ is 164.09 g/mol.
m = 0.50 mol × 164.09 g/mol = 82 g
3. The molar mass of NaCl is 58.44 g/mol.
n = 23.5 g/(58.44 g/mol) = 0.402 mol
4. The molar mass of KMnO₄ is 158.03 g/mol.
n = 79.9 g/(158.03 g/mol) = 0.506 mol
How many grams of carbon disulfide will be produced if .012
kg of sulfur reacts with carbon?
Answer:
14.25g
Explination:
I found this answer on quizlet titled, "Chem Quizlet" by jamie_barbara
⚠️LINKS WILL BE REPORTED⚠️ // Need answers as fast as possible!
- Electrons always fill orbitals in the same order. Each s orbital holds 2 electrons, each set of p orbitals holds 6 electrons, each set of d orbitals holds 10 electrons, and each set of f orbitals holds 14 electrons. The order in which orbitals are filled, from first to last, is:
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p
Beryllium has 4 electrons. What is the electron configuration of beryllium?
A.
2s^22p^2
B.
1s^22s^2
C.
2s^4
D.
4p^1
Answer:
[tex]1s^2\, 2s^2[/tex].
Explanation:
Electron orbitals in an atom (e.g., [tex]1s[/tex]) are denoted with:
A number, denoting the shell (principal energy level) of this orbital, andA letter, denoting the shape of this orbital ([tex]s[/tex], [tex]p[/tex], [tex]d[/tex], etc.)
There are two aspects to consider when finding the electron configuration of an atom:
The number of electrons that each type of orbitals could hold, andThe order in which the orbitals are filled.The [tex]s[/tex] orbital in each shell could hold up to [tex]2 \times 1 = 2[/tex] electrons (one [tex]s\![/tex] orbital per shell, with up to two electrons.)
The [tex]p[/tex] orbitals in each shell could hold up to [tex]2 \times 3 = 6[/tex] electrons (three [tex]p\![/tex] orbitals per shell, with up to two electrons in each orbital.)
The [tex]d[/tex] orbitals in each main shell could hold up to [tex]2 \times 5 = 10[/tex] electrons (five [tex]d\![/tex] orbitals per shell, with up to two electrons in each orbital.)
Refer to the order in which the orbitals are filled (Aufbau principle.)
The first orbital to be filled would be [tex]1s[/tex] (the [tex]s[/tex] orbital of the first shell,) accommodating up to [tex]2[/tex] electrons.The second orbital to be filled would be [tex]2s[/tex] (the [tex]s[/tex] orbital of the second shell,) accommodating up to [tex]2[/tex] electrons.All four electrons of Beryllium are thus assigned to the [tex]1s[/tex] and [tex]2s[/tex] orbitals. In a ground-state Beryllium atom, orbitals [tex]2p[/tex] and beyond would contain no electrons.
Notation:
Two electrons in the [tex]1s[/tex] orbital: [tex]1s^{2}[/tex] (the superscript denotes the number of electrons in this orbital (or group of orbitals).)Two electrons in the [tex]2s[/tex] orbital: [tex]2s^2[/tex].Write the non-empty orbitals in the order by which they are filled:
[tex]1s^2\, 2s^2[/tex].
How many moles are in 15.2 grams of Calcium (Ca)?
Answer:
There are 0.379 moles of Ca in the given sample.
Explanation:
Hey there!
We're given that we have 15.2 grams of Ca (Calcium). We need to convert grams to moles.
There are many different conversion types for moles. A few examples are:
grams to molesmoles to gramsgrams to particlesmoles to litersThere are really endless possibilities for conversion factors. Since we want to find the number of moles in a certain sample, we first need to define what a mole is.
Mole - a unit of measurement in chemistryA mole is one unit of a certain item. For instance, one cup would be equivalent to one mole. Moles are simply a hypothetical unit in chemistry that act as a placeholder.
Now, how do we find the number of moles?
We know that a mole of something is one of that substance. In this case, we're referring to one atom of Calcium.
Therefore, we need to reference a periodic table to understand what the mass of one atom of calcium is equivalent to. I'll be using the official AP Chemistry periodic table as issued by the College Board.
When we reference the periodic table, we see the mass of one atom of calcium is equivalent to 40.08 amu (atomic mass units).
We learn in chemistry that we can use the terms amu and grams interchangeably, so we have learned that one mole of calcium is equivalent to 40.08 grams.
How do we work this out?
Now, we need to find out how many moles are in 15.2 grams of calcium. We can use dimensional analysis to work this out.
Our starting unit will be 15.2 grams of Ca.
[tex]\text{15.2 grams Ca}[/tex]We want to convert this into moles, so we need to cancel out our grams value. Additionally, since we know that we have 40.08 grams of Ca in one mole, we can set these up as two ratios:
[tex]\displaystyle \frac{\text{40.08 grams Ca}}{\text{1 mole Ca}}[/tex][tex]\displaystyle \frac{\text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]These ratios can be used to express the relationship between the moles of calcium and the mass of one calcium atom. However, we need our value of grams to cancel out, so since we will be using cross multiplication in our dimensional analysis, we need to use the ratio with grams on the bottom.
Now that we have selected our ratio, we can set up a multiplication problem of our two ratios:
[tex]\displaystyle \text{15.2 grams Ca} \times \frac{\text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]
We assume that we have a denominator of 1 below 15.2 grams Ca.
Now, we perform our multiplication.
[tex]\displaystyle \frac{\text{15.2 grams Ca} \ \times \ \text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]
We see that our remaining unit is going to be mole(s) Ca, so we can go ahead and drop our grams Ca unit.
[tex]\displaystyle \frac{\text{15.2} \ \times \ \text{1 mole Ca}}{\text{40.08}}[/tex]
Now, we need to simplify a little bit.
[tex]\displaystyle \frac{\text{15.2}}{\text{40.08}} = \text{? moles Ca}[/tex]
Finally, let's divide our fraction and evaluate our equation to find the value of moles Ca.
[tex]\displaystyle \frac{15.2}{40.08} = \text{0.379241517 moles Ca}[/tex]
Are we done yet?
Not just yet! To complete our work, we need to find the number of significant figures we can use. We are given two values in which we can use to judge how many significant figures we are limited to.
15.2 -- Three significant figures40.08 -- Four significant figuresIn chemistry, we always use the least number of significant figures for precision calculations, so we need to round our answer to three significant figures.
[tex]0.379241517 \approx 0.379[/tex]
Therefore, there are approximately 0.379 moles of Ca in the given sample.
how many grams of silver chloride are produced from 15.0 g of silver nitrate
Answer:
4.2 g
Explanation:
A solution has a
pH of 2.5.
Answer the following questions.
pOH =
[H]=
[OH]=
Answer:
pOH = 11.5
[H⁺] = 0.003 M
[OH⁻] = 3 × 10⁻¹² M
Explanation:
The computation is shown below:
Given that
pH = 2.5
Based on the above information
We know that
pH + pOH = 14 ⇒ pOH = 14 - pH
pOH = 14 - 2.5
pOH = 11.5
[H⁺] = 10^(-pH) = 10^(-2.5)
[H⁺] = 0.003 M
[OH⁻] = 10^(-pOH)
= 10^(-11.5)
= 3 × 10⁻¹² M
[OH⁻] = 3 × 10⁻¹² M
Hence, the above represents the answer
PLEASE HELP!!! I will mark brainliest I am really struggling with these problems
Answer:
21883.75 Joules are required to melt the ice!
Redox reactions refer to a pair of reactions in which a particular oxidation is coupled to a corresponding reduction.
a. True
b. False
Answer:
A. True
Explanation:
what statement is the best description of a chemical bond
Answer:
A chemical bond holds atoms together.
Which letter indicates the most sudden change in temperature
Answer:
J 9. , indicates the most sudden change in temperature
How many moles would be present in a gas contained in a 100.0 mL vessel at 25.0oC at a pressure of 2.50 atm?
Answer:
n = 0.0102 mol.
Explanation:
Hello there!
In this case, according to the ideal gas law, which allows us to set up a relationship among volume, pressure, temperature and moles, we can define it as:
[tex]PV=nRT[/tex]
Thus, given the volume in liters (0.1000 L), temperature in kelvins (298.15 K) and pressure in atmospheres (2.50 atm), we can solve for moles as shown below:
[tex]n=\frac{PV}{RT}[/tex]
Thereafter, we plug in the aforementioned values to obtain:
[tex]n=\frac{2.50atm*0.1000L}{0.08206\frac{atm*L}{mol*K}*298.15K}\\\\n=0.0102mol[/tex]
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Spiders create their webs on the stems and trunks of trees. The tree is unaffected by the spider web.
1.predation
2.commensalism
3.parasitism
4.mutualism
Answer:
it would be 2
Explanation:
A hydrogen fuel cell is an electrochemical reactor in which oxygen and hydrogen gas are reacted to produce energy. Rather than combusting hydrogen in the presence of oxygen, the overall reaction (1/2) O2 H2 → H2O is actually carried out as two `half-reactions’ occurring at separate electrodes. To complete the reaction, this forces electrons to pass through an external circuit from one electrode to the other, and this current can be used to do work; e.g., by driving a motor. Typical operating conditions for a solid-oxide fuel cell are 500-900 C and 5-15 bar. Consider a fuel cell in which a pure oxygen stream and a pure hydrogen stream enter at 11 bar and 700 C with stoichiometric flowrates. Assume that these reactants are consumed completely, and that the water generated by the reaction leaves in a third stream at the same T and P. Assume that the fuel cell operates at steady-state with a uniform temperature of 700 C. a) Write simplified first and
Answer:
(d) Why is the fuel cell in Question (c) described as an alkaline fuel cell? (e) Another type of fuel cell uses methanol instead of hydrogen.
Explanation: