Answer:
I dont care I want pionts
How many molecules are in 25 grams of NH3
How many atoms are in 25.00 g of B?
A. 1.393 x 10^24 atoms of B
B. 1.333 x 10^23 atoms of B
C. 2.16 x 10^26 atoms of B
D.217 x 10^24 atoms of B
Thanks for all the efforts :)
Answer:
There are 1.393 x 10²⁴ atoms in 25.00 g of B.
Explanation:
Hey there!
We are given a value, in grams, that we need to convert to a number of atoms.
We can convert grams to atoms by using Avogadro's Number ([tex]N_A[/tex]). This number is equivalent to [tex]6.022 \times 10^{23}[/tex].
This number can be used to convert any values to:
atomsmoleculesformula unitsmolesIn order to do this problem, we will need to use dimensional analysis (DA). This process allows us to convert from grams to atoms.
We need to set up our ratios in order to work this out. We can use a periodic table to help us through this next part of the problem.
1. Locating the number of moles of B in the sample
We first need to find the amount of moles of boron (B) there are in the sample.
Checking a periodic table, the atomic mass in atomic mass units (amu) is 10.81 amu.
Atomic mass units can easily be converted to grams and these units can be used interchangeably.Therefore, for each atom of boron, it weighs 10.81 grams to us. This is equivalent to the mass of one mole of boron.
To find the number of moles, we have two possible ratios we can use:
[tex]\displaystyle \frac{1 \ mole \ B}{10.81 \ grams \ B}[/tex][tex]\displaystyle \frac{10.81 \ grams \ B}{1 \ mole \ B}[/tex]These ratios mean the same thing, but we need to convert our final unit to moles.
We are given a sample in grams, and when dividing our units, we need to keep moles.
Since the first portion of our expression is in grams, we need to have grams in the bottom of our expression.
[tex]\displaystyle 25.00 \ \text{grams B} \ \times \frac{1 \text{mole B}}{10.81 \ \text{grams B}}[/tex]We can now simplify the expression. Our grams B unit will cancel out, so we are therefore left with moles B remaining.
2. Locating the number of atoms in the sample
Now with our equation, we can convert our number of moles that would be solved if we stopped with the above. However, we need to convert to atoms.
We use Avogadro's number and create a ratio with that of moles.
[tex]\displaystyle \frac{6.022 \times 10^{23}\text{atoms}}{1 \text{mole B}}[/tex][tex]\displaystyle \frac{1 \text{mole B}}{6.022 \times 10^{23} \text{atoms}}[/tex]We need to cancel out our moles and end with atoms, so we must have moles in the denominator. Therefore, we use the first ratio.
Using our previous expression, we multiply by this new ratio and solve the expression.
[tex]\displaystyle 25.00 \ \text{grams B} \ \times \frac{1 \text{mole B}}{10.81 \ \text{grams B}} \ \times \frac{6.022 \times 10^{23}\text{atoms}}{1 \text{mole B}}[/tex]This expression can now be operated. You will need a calculator to perform this calculation.
Our numerator is:
[tex][(25.00 \times 1 \times (6.022 \times 10^{23})][/tex]Plugging this into a calculator, we get:
[tex]1.5055 \times 10^{25}[/tex]Our denominator is:
[tex](1 \times 10.81 \times 1)[/tex]This simplifies to:
[tex]10.81[/tex]Dividing our numerator and denominator:
[tex]\displaystyle \frac{1.5055 \times 10^{25}}{10.81}[/tex]Plugging this into a calculator, we get:
[tex]1.392691952 \times 10^{24}[/tex]3. Simplifying with significant figures
Now, we need to take into account that we have significant figures. We are given this original value:
[tex]25.00[/tex]This value has four significant figures, which means we need to round our value we received above to four significant figures.
[tex]\approx 1.393[/tex]Our units are added as well as our scientific notation:
[tex]1.393 \times 10^{24} \ \text{atoms of B}[/tex]Therefore, our final answer is choice A.
Select some particular plant or animal and find out how it has been improved because of the study of genetics. The following examples are given, but you may select some other topic if you like. Be sure that you have the topic and the method (written or oral) of reporting approved before you do your research. If you choose an oral report, it should be at least 3 minutes in length. If you choose a written report it should be at least 500 words in length.
Do some research into thornless varieties of plants.
What plants are available which do not have thorns?
Is thornlessness a mutation?
When and where was the possibility of growing thornless varieties of plants discovered?
How do these varieties compare with the variety that has thorns?
Consult seed catalogs, gardening books, and magazines in the library.
Do some research into the new variety of pumpkins that do not have hulls on their seeds.
Is the flavor of the new variety as good as the flavor of the older varieties, or is the new variety raised only to have seeds without hulls?
How are the seeds prepared?
Is the pumpkin seed a good source of protein?
Consult seed catalogs, gardening books, and gardening magazines.
Study the potato famine in Ireland.
Study how the use of some modern types of potatoes can help to overcome such famines.
Give some examples of potatoes which are hardy against disease.
Study the careful breeding experiments that resulted in disease resistant potatoes.
What makes them hardier and more disease resistant?
What makes them hardier and more disease resistant?
Do some research to find out about the new breeds of cattle that provide much better beef than the older breeds.
Consult a genetics book from the library to determine the names of such cattle.
what makes these breeds better? Are they cared for the same way? Do they have any drawbacks in terms of cost of breeding and raising?
You may want to investigate some of the diseases which are inherited.
Consult a genetics textbook from the library.
You may also need to look up some of these in a medical textbook or the Journal of Heredity.
Who is more likely to inherit them? Why?
Pls Pls Pls answer ASAP!!!
Answer:
number one and and the third one but im not sure srry if i got it wrong
How many atoms are in 24.23 moles of Pb?
Answer: There are 3.3×1023atoms in 0.54 moles Pb. Explanation: To calculate the number of atoms in Pb, we use Avogadro's number,
Explanation:
How many atoms are present in 2.79 mol of NH3?
Answer:
2.79 mol NH3 have 2.79 mol of N atoms. Answer is 1.68*10²⁴ N-atoms
Calculate the number of moles in 3.01 x 10²² atoms of calcium.
Answer:
Using dimensional analysis:
3.01x1022 molecules CO2 x 1 mol CO2/6.02x1023 molecules x 44. g CO2/mole = 2.20 g CO2
Explanation:
Help would be appreciated t.t
Answer:
a) H3PO4 (aq) + 3 KOH (aq) → K3PO4 (aq) + 3 H2O (l)
b)
AgNO3 (aq) + NaCl (aq) → AgCl (s) + NaNO3 (aq)
c)
Ca(OH)2 (s) + 2 H3PO4 (aq) → Ca(H2PO4)2 (s) + 2 H2O (l)
d)
2 KI (aq) + Pb(NO3)2 (aq) → 2 KNO3 (aq) + PbI2 (s)
e)
3 H2SO4 (aq) + 2 Al(OH)3 (s) → 6 H2O (l) + Al2(SO4)3 (aq)
All balanced equation for each reaction!!
1. If 20 moles of HCl was placed in 40 liters of an
NaOH solution, what was the molarity of the NaOH
solution?
A) 0.50 M
B) 2.0M
C) 1.5 M
D) 4.0 M
Answer:
A) 0.50 M
Explanation:
The computation of the number of molarity of the NaOH is given below:
As we know that
Molarity = Moles ÷ liters
where
Moles is 20
And, the liters is 40
So, the molarity is
= 20 ÷ 40
= 0.50 M
hence, the molarity of the NaOH solution is 0.50 M
Therefore the A option is correct
What is baking powder
Answer:
8-)
Explanation:
Baking powder is a dry chemical leavening agent, a mixture of a carbonate or bicarbonate and a weak acid. The base and acid are prevented from reacting prematurely by the inclusion of a buffer such as cornstarch. Baking powder is used to increase the volume and lighten the texture of baked goods
What is the total pressure in a container with 256 mm Hg of Oz, 198 mm Hg of He,
and 48 mm Hg of N2?
Answer:
P(total pressure) = 504 mmHg = 504mm/760mm/atm = 0.663 atm
Explanation:
Apply Dalton's Law of Partial Pressures.
P(total) = ∑Partial Pressures = ∑(256mm + 198mm + 48mm) = 504 mmHg
P(total pressure) = 504 mmHg = 504mm/760mm/atm = 0.663 atm
Question :
➠Define Intertia .
Answer:
The inability to change the position by itself is defined as inertia.
When the offspring has a new genetic variation that a government neither of us parents it is called
S8 + 12 O2 —> 8 SO3 what volume of oxygen would be required to completely react with 45.7g of S8
Answer:
47.9L of oxygen would be required
Explanation:
Assuming oxygen gas is at STP
Based on the reaction:
S₈ + 12 O₂ → 8SO₃
1 mole of S₈ (Molar mass: 256.52g/mol) reacts with 12 moles of oxygen.
To solve this question we must find the moles of S₈ added. With the reaction we can find the moles of O₂ and using PV = nRT we can find the volume of oxygen required:
Moles S₈:
45.7g * (1mol / 256.52g) = 0.178 moles S₈
Moles O₂:
0.178 moles S₈ * (12 moles O₂ / 1mol S₈) = 2.138 moles O₂
Volume O₂:
PV = nRT
V = nRT / P
Where V is volume
n are moles = 2.138 moles
R is gas constant 0.082atmL/molK
T is absolute temperature = 273.15K at sTP
P is pressure = 1 atm at STP
V = 2.138mol*0.082atmL/molK*273.15K / 1atm
V = 47.9L of oxygen would be required
Answer:
180.2 L
Explanation:
(Earth and Space Science)
The sun rotates ___.
A. Around earth once per year.
B. Every 31 days.
C. At different speeds along it's sphere.
D. Once per year
Answer:
B.every 31 days
Explanation:
i need brainlieast pls help me pls pls oooo
What impact can wetlands reducing flood do to future generations?
Answer:
Wetlands prevent flooding by temporarily storing and slowly releasing stormwater. Wetlands also reduce water flow, thus allowing sediments and associated pollutants to settle out. Beneficial microor- ganisms (called biofilm) live on wetland plants and process some forms of pollution.
Explanation:
How are some islands formed? Do you think islands can form at any time? Where are we more likely to find islands?
Answer:
Islands are formed by volcanic eruptions and tectonic plates movements.
Explanation:
Islands are land masses that are covered with water on all its sides. Islands are mainly formed by the volcanic eruptions or by the tectonic forces. When volcanoes erupt, they try to build up layers of the lava that eventually emerged through the water surface and forms an island.
Islands can be also formed when tectonic plates forces each other beneath the water body and land masses rise up to form islands.
Yes islands can be formed at any time. But it takes time for the formation of an island.
Islands are more likely to occur on the seas, oceans, lakes or river, etc.
Particle motion in ice is _________
than particle motion in water.
Answer:
slower(less faster)
the particles motion in a liquid state of a substance is faster than the particle motion in substance's solid state.
Particle motion in ice is slower than particle motion in water.
What is the motion of particles?The motion of particles is the random movement of the particles or electrons inside the atoms. These movements happen due to an increase in temperature or heat.
There are three types of matter, solid, gas, and liquid. These matters have different particle movements. Because these matters have different organizations of charged particles within them.
As ice is solid, the particles in solid have compact particle present. These particles are near to each other and do not move. And water is liquid, its particles move randomly. As liquid move and get the shape of the container. Its particles are in motion.
Thus, particle motion in ice is slower than particle motion in water.
To learn more about the motion of particles, refer to the link:
https://brainly.com/question/11155407
#SPJ2
Which theories from the past contributed to today's plate tectonic theory?
O The theory of continental drift and the big bang theory.
O The big bang theory and the theory of natural selection.
O The theory of continental drift and the theory of sea floor spreading.
O The theory of sea floor spreading and the theory of relativity.
Answer:
I believe it's the second one
Explanation:
The big bang theory and the theory of natural selection.
The theory of continental drift and the theory of sea floor spreading from the past contributed to today's plate tectonic theory. Therefore, option A is correct.
What is continental drift ?Continental drift is the theory that the Earth's continents have moved relative to one another over geologic time, giving the appearance of "drifting" across the ocean floor.
Plate tectonics caused continental drift over millions of years. Plate tectonics also explained how plate movement causes volcanoes and earthquakes, as well as how continent collisions create massive mountain ranges.
In the early twentieth century, a scientific theory known as continental drift was proposed to explain this migration of continents. That theory was initially dismissed, but it paved the way for another theory known as plate tectonics, which scientists now accept as an explanation for how the Earth's continents move.
Thus, option A is correct.
To learn more bout the continental drift, follow the link;
https://brainly.com/question/15122129
#SPJ6
please help! science 10 acid and bases!
Complete and balance the following neutralization reactions.
(a) H,SOA + NaOH
(b) HNO3 + KOH
(c) HCl + Ca(OH)2
(d) H PO, + Ba(OH)2
() CH,COOH + NaOH
(1) HNO3 + Sr(OH)2
(g) HF + Fe(OH)3
(h) HBr + Sn(OH)4
Answer:
See explanation
Explanation:
Recall that a neutralization reaction is one in which an acid reacts with a base to yield salt and water only. The equation is only balanced when the number of each atom on the reactant side is the same as the number of the same atom on the product side.
Let us now complete and balance each reaction equation;
(a) H2SO4 + 2NaOH --------> Na2SO4 + 2H2O
(b) HNO3 + KOH ---------> KNO3 + H2O
(c) 2HCl + Ca(OH)2 -------> CaCl2 + 2H2O
(d) 2H3PO4 + 3Ba(OH)2 ------> Ba3(PO4)2 + 6H2O
() CH3COOH + NaOH --------> CH3COONa + H2O
(1) 2HNO3 + Sr(OH)2 --------->Sr(NO3)2 + 2H2O
(g) 3HF + Fe(OH)3 ------> FeF3 + 3H2O
(h) 4HBr + Sn(OH)4 --------> SnBr4 + 4H2O
density = 11g/cm3 volume = 2cm3 what is the mass
Density = 11g/cm³, volume = 2cm³. What is the mass ?
Solution:-We know,
[tex] { \boxed{\bf{\rm \red {Mass \: = \: Density \: × \: Volume}}}} [/tex]
So, Mass = 11g/cm³ × 2cm³
Mass = 22 g
The mass is 22 g. [Answer]Click Exposure and weathering. What forms when rocks break down?
Answer:
Sediments form after weathering
In chemical reactions, the number of atoms in the product is ________________.
A. the same as the number of atoms in the reactants
B. less than the number of atoms in the reactants
C. greater than the number of atoms in the reactants
D. the same as the number of molecules in the reactants
Answer:
A
Explanation:
Questions 4-6 Identify these three equations If they are alpha, beta, or gamma decay.
Answer:
4. gamma decay
5. gamma decay
6. beta decay
No links or files plz
Answer:
ice should start to melt at 1°
What is the mass in grams of 1.8 mol of Magnesium Sulfide?
Answer:
101.466000
Explanation:
N/A
formula unit of Magnesium oxide and Calcium bicarbonate and aluminum carbonate plzzzz
Magnesium oxide : MgO
Calcium bicarbonate: Ca(HCO3)2
aluminum carbonate: Al2(CO3)3 or C3Al2O9
Use the periodic table to select which type of bond is present and which of the listed properties is most likely for each substance.
A =
B =
Answer:
a= Covalent
b=low melting point
c= ionic
d=conduct electricity when dissolved
Explanation:
A tropical climate is a wet climate. Consider a city like Bogota, Colombia which has a tropical climate. Does a tropical climate being a wet climate mean that it will rain every day? Why or why not you live in?
Answer:
No, It will mean lot of rains but not every day
Explanation:
In wet tropical climates, the high clouds trap a lot of heat while balancing incoming and outgoing heat energy. When the number of heat trapping cloud remains very low, then the unstable cool air above the clouds cause lot of rain.
Hence, there will rain frequently but no everyday
Answer:
help me please help me
Explanation:
A tropical climate is a wet climate. Consider a city like Bogota, Colombia which has a tropical climate. Does a tropical climate being a wet climate mean that it will rain every day? Why or why not?
Are the cells in this image prokaryotic or eukaryotic
Answer:
Prokaryotic is the answer!
Explanation:
I know this because, the nucleolus is absent in the image.
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