Answer:
2.14 × 10²² atoms Si
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesStoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
Identify
[Given] 0.0356 mol Si
[Solve] atoms Si
Step 2: Identify Conversions
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
Step 3: Convert
[DA] Set up: [tex]\dipslaystyle 0.0356 \ mol \ Si(\frac{6.022 \cdot 10^{23} \ atoms \ Si}{1 \ mol \ Si})[/tex][DA] Multiply [Cancel out units]: [tex]\dipslaystyle 2.14383 \cdot 10^{22} \ atoms \ Si[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
2.14383 × 10²² atoms Si ≈ 2.14 × 10²² atoms Si
Form similar pairs of words.
Boron : B :: Beryllium :
Answer:
Boron : B :: Beryllium :Be
Explanation:
Boron is an element found in group 13 of the periodic table. It has three electrons in its outermost shell hence a valency of 3.
Beryllium is an element in group two of the periodic table. It has a valency of two hence there are two electrons in its outermost shell.
Boron and beryllium are similar words. The symbol of boron is B while the symbol of beryllium is Be.
Calculate the total energy, in kilojoules, that is needed to turn a 46 g block
of ice at -25 degrees C into water vapor at 100 degrees C.
Answer: The total energy, in kilojoules, that is needed to turn a 46 g block of ice at -25 degrees C into water vapor at 100 degrees C is 11.787 kJ.
Explanation:
Given: Mass = 46 g
Initial temperature = [tex]-25^{o}C[/tex]
Final temperature = [tex]100^{o}C[/tex]
Specific heat capacity of ice = 2.05 [tex]J/g^{o}C[/tex]
Formula used to calculate the energy is as follows.
[tex]q = m \times C \times (T_{2} - T_{1})[/tex]
where,
q = heat energy
m = mass
C = specific heat capacity
[tex]T_{1}[/tex] = initial temperature
[tex]T_{2}[/tex] = final temperature
Substitute the values into above formula as follows.
[tex]q = m \times C \times (T_{2} - T_{1})\\= 46 g \times 2.05 J/g^{o}C \times (100 - (-25))^{o}C\\= 11787.5 J (1 J = 0.001 kJ)\\= 11.787 kJ[/tex]
Thus, we can conclude that the total energy, in kilojoules, that is needed to turn a 46 g block of ice at -25 degrees C into water vapor at 100 degrees C is 11.787 kJ.
4. Assign an oxidation state to the element whose atom is underlined in the following compound: AIH3
O Al: +5
O Al: -5
Ο Ο Ο
Al: -3
O Al: +3
Answer: The oxidation state of Al in [tex]AlH_{3}[/tex] is +3.
Explanation:
The number attained by an atom or substance due to loss or gain of electrons is called oxidation state.
For example, in [tex]AlH_{3}[/tex] it is known that the oxidation state of hydrogen is -1 as aluminum is a cation so it cannot have an oxidation state as 'minus'.
Whereas hydrogen has the property to act both as a cation and an anion.
Let us assume the oxidation state of Al is x in the compound [tex]AlH_{3}[/tex].
Hence, oxidation state of Al is calculated as follows.
[tex]x + 3(-1) = 0\\x - 3 = 0\\x = +3[/tex]
This means that the oxidation state of Al in [tex]AlH_{3}[/tex] is +3.
Thus, we can conclude that oxidation state of Al in [tex]AlH_{3}[/tex] is +3.
If you add 25.0 mL of water to 125 mL of a 0.150 M LiOH solution, what will be the molarity of the resulting diluted solution? 0.0450 M LiOH 0.0647 M LiOH 0.125 M LiOH 0.134 M LiOH
Answer:
solute in a fixed volume of solution
Concentration(c) = number of moles of solute(n) / volume of solution (v)
25.0 mL of water is added to 125 mL of a 0.150 M LiOH solution and solution becomes more diluted.
original solution molarity - 0.150 M
number of moles of LiOH in 1 L - 0.150 mol
number of LiOH moles in 0.125 L - 0.150 mol/ L x 0.125 L = 0.01875 mol
when 25.0 mL is added the number of moles of LiOH will remain constant but volume of the solution increases
new volume - 125 mL + 25 mL = 150 mL
therefore new molarity is
c = 0.01875 mol / 0.150 L = 0.125 M
answer is 0.125 M
Explanation:
did this answer got right
Answer:
0.125
Explanation:
Just completed the test and got it correct.
How many liters of hydrogen (at 0.97atm and 24c) will produce 180 grams of water
I also need to know how to get the answer.
H₂ + ½O₂ → H₂O
2g → 18g
So, 18g water needs 2g H₂
So, 1g water needs 2/18g H₂
So, 180g water needs 2/18 x 180g H₂
→ 20 litres of H₂
Answer:
Explanation:
Molar mass of water, H2O = 2 + 16 = 18
So 180g of water contains 10M
H2 + O -> H2O
10M of Hydrogen is needed to produce 10M of water.
Molar volume at STP = 22.4L
So 10M of Hydrogen at STP = 224L
With Ideal Gas Law, P1V1/T1 = P2V2/T2
At STP, P1 = 1atm, T1=273K
At 0.97atm and 24c (273+24 = 297K), 10M of Hydrogen will take up:
1*224/273 = 0.97*V2/297
V2 = 224*297/273/0.97
= 251.23L
So the answer is 251.23L
What role do stomach enzymes play in digestion? A They transfer food out of the esophagus. B They break down food into smaller parts. C They move food down into the intestines. D They physically mix food with stomach acid.
Answer:
b
Explanation:
Answer:
b
Explanation:
b
Determine which statement is true. A) Electrons travel around the nucleus in circular orbits. B) The Bohr atom is the model currently accepted for electrons in atoms. C) An electron's position and energy (momentum) can be know with certainty simultaneously. D) Currently, scientists know the energies of electrons but only approximate areas (orbitals) where the electrons are probably located.
Answer:
A. True
B. True
C. False
D. False
Explanation:
Electrons travel around the nucleus in circular orbits and moves from one orbit to another orbit when they absorb energy or lose energy. The Bohr atom is the model currently accepted for electrons in atoms because this model provides the right information about presence of electrons around the orbits. Scientists know the energies of electrons as well as the areas (orbitals) where the electrons are probably located with the help of new technology.
Answer:d
Explanationusa test prep
what is the state of matter that takes shape of a container???
Answer:
Liquid and gas is the matter that takes shape of a container
It can also be called fluid since fluid is distributed into liquid and gas
Explanation:
I hope that is enough for your answer, hope this will help
Las sustancias ionicas y los metale sson electricamente neutros. ¿como es esto posible si estan formados por iones, que posen carga electrica?
Answer:
ver explicacion
Explanation:
Los iones se forman cuando las especies químicas pierden o ganan electrones.
Las sustancias iónicas consisten en un ión positivo y negativo cuyas cargas se equilibran exactamente entre sí, por lo que el compuesto iónico es neutro.
Los átomos de metal se mantienen unidos por el enlace metálico. Esto implica la interacción entre iones metálicos cargados positivamente y un mar de electrones negativos. Las cargas positivas de los iones metálicos están exactamente equilibradas por el mar de electrones cargados negativamente, por lo que el metal es neutro.
The radius of the large cylinder of a hydrolic press
20cm and that of the small cylinderis 5 cm. If a force of 100N is applied on the small piston Calculate the force on the large piston. if the piston of the small cylinder move through a distance of 0.4m through what distance can the large piston be raised
Answer: 1) 400N
2)1.6
Explanation:
1) 5cm = 100N of force
so
20cm=400n
2) 0.4 X 4 = 1.6
How many moles are in 243 grams of Al(OH)3?
Answer:
The answer is 78.003558.
We assume you are converting between grams Al(OH)3 and mole.
You can view more details on each measurement unit:
molecular weight of Al(OH)3 or mol
This compound is also known as Aluminium Hydroxide.
Explanation:
Please answer. Brainliest!
The equation is balanced.
Explanation:The number of P atoms in the reactant side is 4 and the number of P atoms in the product side is also 4.
The number of O atoms in the reactant side is 16 and the number of O atoms in the product side is also 16.
The number of H atoms in the reactant side is 12 and the number of H atoms in the product side is also 12.
These results are in accordance with the law of conservation of mass.
#ILoveChemistry
Which of the following is an acid?
Be(OH)2
HCl
LiBr
NH3
Answer:
HCL is your the answer of which is the acid
The acid should be considered as the HCL namely hydrogen chloride (HCl).
What is HCL acid?It is used for neutralization the alkaline agents that acted as the bleaching agent in terms of food, textile, metal.
It should be neutralized at the time of realization into the soil. And, hydrolyzed when it should be exposed to water.
hence, the second option is correct.
learn more about acid here: https://brainly.com/question/18887998
Which term refers to energy stored within the center of an atom?
A. Thermal energy
B. Nuclear energy
C. Chemical energy
D. Light energy
Answer: i'm pretty sure it's b if i remember correctly.
Explanation:
i learned this a while ago so i'm not completely sure.
8)
When an equation is correctly balanced, it must show conservation of
A)
charge but not of mass
B)
mass but not of charge
C)
both charge and mass
D)
neither charge nor mass
Write the complete and net ionic equations for the following reactions. If only the reactants are given, predict the products and balance the equation first.
Explanation:
u can put them in order crossed are spectator ions. hope this helps:)
What type of substance is octane?
Answer:
don't know
Explanation:
Thanks❤ have a nice day
Answer:
Liquid
Explanation:
Octane is a straight chain alkane composed of 8 carbon atoms. It has a role as a xenobiotic. N-octane is a colorless liquid with an odor of gasoline.
Can you guys help!!!
During a certain chemical reaction, the temperature gradually increases.
Which statement best describes this process?
A. It is combustion.
B. It is endothermic.
C. It is a closed system.
D. It is exothermic.
No links!!!
No spams!!
Answer:
D. lt is exothermic is the correct ans
Please help ………………….
Answer:
magnsium po
Explanation:
Plz help fast it’s due very soon
8 moles
Explanation:
in the equation 1 mole of methane is reacting with 2 mole of oxygen
if 1 mole is reacting with 2 moles
so 4 mole will react with 2×4 = 8 moles
Answer:
8
Explanation:
beacuse use the molar ratio of ch4 : O2 which is 1:2 so you times 4 by 2
En términos de energía, ¿a qué se debe que sea más difícil detener un camión en comparación a una bicicleta?
Answer:
hola
Explanation:because si
What is a natural disaster?
Answer:
Explanation:
A natural disaster is a major adverse event resulting from natural processes of the Earth; examples include floods, hurricanes, tornadoes, volcanic eruptions, earthquakes, tsunamis, storms, and other geologic processes
Answer:
A natural disaster is a natural, major harmful event resulting from natural processes of the Earth such as floods, earthquakes, or hurricanes, tornadoes, volcanic eruptions, tsunamis, storms, and other geologic processes that causes great damage or loss of life.
Which of the following are equal to 32°F?
A. 0°C
B. 273 K
C. 100°C
D. 373 K
Answer:
A. 0°C............... sorry, the anwser has to be 20 characters long
How many moles of sucrose
are in 5.25x1029 sucrose
molecules? (in scientific notation)
Answer:
8.72 × 10^5 moles
Explanation:
To find the number of moles in 5.25 x 10^29 molecules of sucrose, we divide the number of molecules by Avagadro constant (6.02 × 10²³ molecules). That is;
no. of moles = no. of molecules ÷ 6.02 × 10²³ molecules
In this case of sucrose, no of moles contained is as follows;
5.25 × 10^29 ÷ 6.02 × 10²³
5.25/6.02 × 10^ (29-23)
0.872 × 10^6
= 8.72 × 10^5 moles
In two or more complete sentences explain how to balance the chemical equation and classify its reaction type.
___NaI + ___Pb(SO4)2 ⟶ ___PbI4 + ___Na2SO4
Porrrrrrffffffaaaaaavvvvvvooooorrrrrrr
Answer:
2.2)solido
2.3)Sólido cristalino
2.4)Sólido amorfo
How do catalysts increase reaction rates? *
By increasing the activation energy.
By broadening the energy barrier.
By forming an activated complex with lower energy.
By changing the net thermodynamics of the reaction.
Answer:
By forming an activated complex with lower energy.
Explanation:
When catalyst is added to a reaction , it forms an activated catalyst which has lower activation energy . So initiation of reaction requires less energy and reaction becomes fast .
Hence third option is correct.
Detecta cuál de las siguientes fórmulas estructurales no cumple con la tetravalencia del carbono (formar cuatro enlaces)
El ejercicio completo con las formulas es el siguiente:
cuál de las siguientes fórmulas no cumple con la tetravalencia del átomo de carbono.
a. CH3-CH2-CH2-OH
b. CH3-CH=CH2
c. CH3-CH2=CH2
d. CH3-CH2-CH3
Answer:
La respuesta correcta es la opción C
Explanation:
En la formula C, podemos ver claramente que no se cumple con la tetravalencia del carbono pues al sumar el total de las valencias del carbono nos da 5
CH3 - CH2 = CH2 = Total de valencias del carbono 5
1 + 2+ 2 = 5
Para que la formula sea correcta debe eliminarse un hidrogeno quedando la formula de la siguiente manera:
CH3 - CH = CH2
1 + 1 + 2 = 4
How many significant digits are in the value 0.0050340?
Answer:
6
Explanation:
6, because the number after decimals are considered significant but the 0 after the last number is not significant.
10 uses of non-metals
Answer: 10 uses
Explanation:
1] Oxygen is used for breathing.
2] Chlorine is used for purifying water.
3] Phosphorous is used in crackers.
4] Non - metals like nitrogen is used in fertilizers.
5] Graphite is used as a good conductor of electricity.
6] Pottassium is used in fertilizers.
7] Nitrogen is used by plants.
8] Graphite is used in making leads.
9] Carbon is used as a fuel.
10] Bromine is used in dyes and pesticides