Answer:
118,438.5 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L}\\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{7.13 \times {10}^{28} }{6.02 \times {10}^{23} } \\ = 118438.538...[/tex]
We have the final answer as
118,438.5 molesHope this helps you
please help question is in photo will give brainiest
Answer:
D
Explanation:
Consider the reaction between 75.5 mL of 0.247 M barium hydroxide and 95.0 mL of 0.330 M HCl. Find the mole ratio of hydrochloric acid to barium hydroxide, compare to the theoretical one, and determine the limiting reactant.
Answer:
Explanation:
Ba( OH)₂ + 2HCl = BaCl₂ + 2H₂O .
75.5 mL of 0.247 M barium hydroxide = .0755 x .247 = .01864 moles
95.0 mL of 0.330 M HCl = .095 x .33 = .03135 moles
mole ratio of hydrochloric acid to barium hydroxide
= .03135 / .01864 = 1.68
theoretical ratio = 2 /1 = 2
As the theoretical ratio is more , therefore HCl is the limiting reactant .
Hormones are secreted by glands in the human body. The hormones control different functions of the body by targeting specific organs and controlling the way their cells work. Which organ system is made of these hormone-producing glands?
Answer:
Bb
Explanation:
What level of ecological organization so all the owls in a certain area represent?
The owls in the certain area located in the picture represent a population, they are formed up as a small group of animals representing a small species.
The level of ecological organization that all owls in a given area represent is the population of owls in a given area.
What is ecology?In ecology, the organism, population, community, ecosystem, and biosphere are among the levels of organization. A population is a collection of creatures from the same species that coexist in one location and communicate with one another.
Researchers in the field of ecology focus on five major levels: organism, population, community, ecosystem, and biosphere. These levels are sometimes studied separately and other times they overlap. Let's examine each stage one by one.
The owls in the particular location shown in the image are a population; they are made up of a few individuals representing a single small species.
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how do i do this question please help me
Answer:
3
Explanation:
The reaction is given as:
H₂S + O₂ → SO₂ + H₂O
Let us balance the chemical equation.
We take some letters and we use them as the coefficient to balance the equation;
aH₂S + bO₂ → cSO₂ + dH₂O
Now,
Conserving H;
2a = 2d
Conserving S;
a = c
Conserving O;
2b = 2c + d
Let a = 1, d = 1, c = 1, b = [tex]\frac{3}{2}[/tex] and multiply through by 2;
a = 2, b = 3, c = 2 and d = 2
So, the balanced reaction equation is given as;
2H₂S + 3O₂ → 2SO₂ + 2H₂O
Read the hypothesis below. Hypothesis: if a steel surface is wet with water, then the friction will be reduced, which question best matches the hypothesis ???
Answer:
how will water affect the force of friction
90% sure
Molecules are related to matter because
Can someone please help me!! What are the parts of a Bunsen burner if possible add a picture and name please thanks
Bunsen burner is an instrument which is used as a source of heat using natural gas or petrol. It is used for the heating, sterlization, and combustion. Bunsen burner is named after its inventor Robert bunsen.
____________________________________Mechanism:Burner provide a single, continuous flame by mixing gas with air in a controlled fashion. The ratio of gas to air that is mixed together can be manually adjusted, allowing the user to control the intensity, temperature, and size of the flame.
____________________________________PICTURE IS ATTACHED BELOW____________________________________Best Regards!'Borz'A scientist was studying layers of earth in the side of a mountain. In the lower layers, she found fossils of reindeer and polar bears. In the upper layers, she found fossils of coyotes and squirrels. Which conclusion most likely explains the different fossils?
Group of answer choices
The climate was very cold in earlier time periods and became warmer in later time periods
The climate was very hot in earlier time periods and became colder in later time periods.
The climate was wet in earlier time periods and became drier in later time periods.
The climate was dry in earlier time periods and became wetter in later time periods.
Answer:
The climate was very hot and became colder in later time periods.
Answer:
The climate was very hot in earlier time periods and became colder in later time periods.
How to draw a covalent bonding plz help ppl
Explanation:
A single covalent bond is made up of 2 electrons (one from each atom). It is represented with a single line.
Each line is represented as one dot and one cross (. x)
A double covalent bond is made up of 4 electrons (2 from each atom). It is represented using 2 lines. As dot and cross, it will be represented with 2 dots and 2 crosses.
A triple covalent bond is made up of 6 electrons (3 from each atom). It is represented using 3 lines. As dot and cross, it will be represented with 3 dots and 3 crosses.
Know the number of electron (s) needed by the atom to have noble gas configuration / stable (Key: You should know your electron arrangement / group number / Refer to table provided)*.
Groups and the number of electrons needed for atoms to have noble gas configuration or have full outer shell(s).
Group 4: Four (4) electrons needed for the outer shell to become full / noble gas configuration;
Group 5: Three (3) electrons needed by the atom to have a full outer shell / noble gas configuration;
Group 6: Two (2) electrons needed
Group 7: One (1) electron needed
Which statement best describes the physical properties of solid, liquid, and gas fuels?
-Solids and liquids decompose and transform into non-flammable vapors when exposed to their ignition point.
-The vapors produced by decomposed fuels combust into flames when heated to their flammable point.
Which statement best describes the physical properties of solid, liquid, and gas fuels? -Liquid fuels take longer to ignite than solid or gas fuels.
-Liquid fuels require the least amount of time to ignite.
Answer:
I did not understand
i donot know it is correct
(i think 2 one is the best)
Explanation:
Can someone help me with this?-- 15 pts!
2H2 + O2 → 2H2O
At the beginning of the reaction, it is measured that there are 15.0 g of hydrogen (H2) and 97.0 g of oxygen (O2).
What is the theoretical yield for the water that will be produced in the reaction? (M H2O = 18.0 g/mol; M CH4 = 16.0 g/mol)
2.73 x 101 g H2O
1.34 x 102 g H2O
1.08 x 102 g H2O
5.38 x 100 g H2O
Answer:
1.08 x 10^2 gm of H2O
Explanation:
number of moles of O2 = 97g /32 g/moles = 3.03 moles
3.03 moles of O2 produces 6.06 moles of H2O
amount of water produced = 6.06 mol x 18 g /mol = 109.08 g = 1.08 x 10^2 g
NEED ASAP PLS!!
What important contribution did Einstein make concerning the relationship between energy and matter?
a.) A small amount of matter can be changed into a huge amount of energy
b.) A small amount of energy is created when large amounts of matter is changed
c.) The creation of energy will result in matter
d.) Matter can never be created
Answer: It is a
Explanation:
Which of the following has the largest atomic radius?
Na
CI
C
Mg
Be
Answer:
Na
Explanation:
On the periodic table, the atomic radius of an atom typically decreases when going from left to right and increases when going from top to bottom.
Identify the isotope that has atoms with 28 neutrons, 23 protons, and 23 electrons
A. ^28 Ni
B. ^23 V
C. ^23 Mn
D. ^51 Sb
E. ^51 V
Answer:
E. ^51 V
Atomic number (number of protons in the nucleus): 23
Atomic symbol (on the periodic table of the elements): V
Atomic weight (average mass of the atom): 50.9415
Density: grams per cubic centimeter
Phase at room temperature: Solid
Melting point: 3,470 degrees Fahrenheit (1,910 degrees Celsius)
Boiling point: 6,165 F (3,407 C)
Number of isotopes (atoms of the same element with a different number of neutrons): 2; one stable V-51; one radioactive V-50
Most common isotopes: V-51 (99.75 percent natural abundance)
what is set in mathematics
Answer:
i dont get your question Man
In mathematics, a set is a well-defined collection of distinct objects
♥plz give me brain list it would really help a lot♥
♥ お力になれて、嬉しいです！♥When HNO3 and Au are mixed together, what do you expect to happen, and why?
No reaction, because Au is above H on the activity series and they cannot react
No reaction, because Au is lower on the activity series and cannot replace H
They form Au(NO3)2 and H2, because Au is more reactive and able to replace H
They form Au(NO3)2 and H2, because they trade places in a double replacement reaction
Answer:
B
Explanation:
There can be no reaction because Au is above H on the activity series and cannot react.
Answer: B is correct
Explanation: I took the quiz
water in a plate disappear after some hour when it is kept in the sun why
Answer:
This happened because of evaporation, the sun evaporated the water.
Answer:
Because if you place the plate filled with water in the sun then a small amount of water will be dried up by the sun's heat.
What is a chemical formula?
Answer:
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus and minus signs.
Explanation:
Name the 3 elements, in order, that make up a very important part of Thanksgiving. (Spell out a word with chemical symbols)
Answer:
eat well, stay well, and have fun ∛π⇅πΔΔΔ≅≅⇵↑↓∫∫↑
Explanation:
Answer:
Chemical element symbols are one- and two-letter abbreviations for the element names. They are used to make the periodic table and chemical formulas easier to read. You can combine the symbols to make words. Here is a list of English words made from periodic table element symbols. There are thousands of words that can be written using these symbols, so experiment to see if you can write your name or fun messages that show your chemistry savvy.
Ca(OH)2 + 2HCl → CaCl2 + 2H2O Which of the following is true about the equation
Answer:
This equation is a double reaction
Explanation:
I hope this is the answer
Answer:
ca(OH)2 is the base and CaCI2 is the salt
Explanation:
Write a balanced chemical equation for the following: magnesium metal is burned in oxygen to produce magnesium oxide.
2Mg(s)+O₂(g)⇒2MgO(s)
Further explanationEqualization of chemical reactions can be done using variables. Steps in equalizing the reaction equation:
1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c, etc.
2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index (subscript) between reactant and product
3. Select the coefficient of the substance with the most complex chemical formula equal to 1
Reaction(syntesis / combination)
Mg(s)+O₂(g)⇒MgO(s)
give coefficient
aMg(s)+bO₂(g)⇒MgO(s)
Mg, left=a, right 1⇒a=1
O,left=2b,right 1⇒2b=1,b=0.5
Mg(s)+0.5O₂(g)⇒MgO(s) x 2
2Mg(s)+O₂(g)⇒2MgO(s)
Why can't you squeeze a sealed plastic syringe that is completely filled with water??
Answer:
Water has less compressibility. When you squeeze it, it has no place to escape.
Explanation:
2] Calculate the percentage of the element forming sugar glucose C6H1206
[C=12, H=1, 0=16]
Answer:
wouldn't it be 52
Explanation:
What is the energy (in joules) and the wavelength (in meters) of the line in the spectrum of hydrogen that represents the movement of an electron from Bohr orbit with n = 3 to the orbit with n = 5?
AYOSOMEONEHELPMEWITHTHESETWOMULTIPLECHOICEQUESTIONS
I’ll give a brainest
Answer:
b. close to 0 degree celsius
Explanation:
100 g * ( x-0)= 500 g * ( 25-x) , where x is the new temperature reached
if we solve for x , we get 20 degree celsius
i.e. the temperature of ice increases to 5 degree celsius and the temperature of water drops to 5 degree celsius
hope it helps.
Which element rarely reacts because it has 8 electrons in its outer shell?
A. Bromine
B. Xenon
C. Arsenic
D. Potassium
Answer:
B. Xenon
Explanation:
A.P.E.X
According to the electronic configuration,the element which rarely reacts is xenon as it has 8 electrons in it's valence shell.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
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Which of the following instruments is a combination of a percussion and a stringed instrument?
A) saxophone
B) piano
C) oboe
D) tambourine
Answer:B
Explanation:
Which of the following is a INCORRECT ionic compound formula?
MgO
Na20
MgCl
NaCl
Answer:
Na2O
explanation.
Ionic bonds refers to complete transfer of electrons from one atom to another
A balloon contains 3.20 L of helium. The pressure is reduced to 59.0 kPa, and the
balloon expands to occupy a volume of 5.50 L. What was the initial pressure exerted on
the balloon?
Answer:
101.4pKa
Explanation:
Given parameters:
Initial Volume of helium = 3.20L
Final pressure of helium = 59kPa
Final volume on helium gas = 5.5L
Unknown:
Initial pressure exerted on the balloon = ?
Solution;
To solve this pressure - volume problem, we simply apply the Boyle's law.
It states that "the volume of a fixed mass gas varies inversely as the pressure changes if the temperature is constant".
Mathematically;
P1 V1 = P2 V2
Now, insert parameters and solve;
P1 x 3.2 = 59 x 5.5
P1 = 101.4pKa