Answer:
Explanation:
Given that:
The mass of sodium crystal = 4.14 g
As a result, the number of atoms in the sodium crystal is:
[tex]=4.14 \g \times \dfrac{ 1 \ mol}{23.0 \ g }\times \dfrac{6.023 \times 10^{23} \ atoms}{1 \ mol}[/tex]
= 1.084 × 10²³ atoms
In the valence orbital of the sodium atom, there is just one electron.
As a result, the number of molecular orbitals produced by these atoms is= 1.084 × 10²³ molecular orbital
Because valence bands are created from occupied molecular orbitals, the number of valence bands created from the aforementioned molecular orbitals is:
[tex]= \dfrac{ 1.084 \times 10^{23}}{2}[/tex]
= 5.420 × 10²² orbitals.
Who used scientific investigations to study atoms?
Check all that apply.
Dalton
Democritus
Rutherford
Thomson
Answer:
Rutherford used scientific investigation to study atoms.
Scientist who used scientific investigations to study atoms is Rutherford.
What are atoms?Atoms are the basic fundamental or functional unit of any substance present in the nature.
Rutherford is also known as the father of nuclear physics and he did scientific investigation on the massive part of atom called nucleus he discovered that there are two types of radiation, coming from the uranium atom are alpha and beta particles.
Scientific investigation is a method in which scientist will study, perform and observe results for the experiment.
Hence Rutherford used scientific investigation.
To know more about Scientific investigation, visit the below link:
https://brainly.com/question/17216882
3 A soil has 70% sand, 20% silt
and 10% clay. What kind of soil is it? How do its proportions need
to be changed to make it
into a loam?
Today, as part of the series of posts on soils, we are going to look at ‘soil texture’. Soil forms the basis for all life but it’s important to know about its mineral constitution as well as its biological profile.
Texture refers to the ‘feel’ of the soil. This is affected by the constituent materials found within it, specifically sand, silt and clay particles. A coarse sand will feel gritty but a wet clay will feel heavy and sticky. The texture of a soil has a direct impact on the way the soil reacts to certain environmental conditions – for example, towards drought or heavy rain (with sandy soils more freely draining).
There is a big difference in the size of the different particles.
Coarse sand = diameter 2-0.2mm
Fine sand = diameter 0.2-0.02mm
Silt = diameter 0.02-0.002mm
Clay = diameter less than 0.002mm
Note how the clay particles are much smaller than the sand particles – this is important as it means the total surface area of a clay soil is much greater and so the capacity to hold water is also much greater.
Between the sand, silt and clay particles there are lots of pores. In fact a soil as a whole is generally 45% mineral, 5% organic matter (depending on the soil) and 50% pore space through which air and water can pass.
Sand –
Made up of weathered primary rock minerals.
The particles are irregular in outline.
They are large and so do not pack together easily.
Large pore spaces in between.
Air gets in very easily and water flows rapidly through it.
Silt –
Write out the steps to finding the Empirical Formula.
4- 4110 kg of R-134a at 300 kPa fills a rigid container whose volume is 14 L. Determine the temperature and total enthalpy in the container. The container is now heated until the pressure is 600 kPa. Determine the temperature and total enthalpy when the heating is completed.
The correct question is: 10 kg of R-134a at 300 kPa fills a rigid container whose volume is 14 L. Determine the temperature and total enthalpy in the container. The container is now heated until the pressure is 600 kPa. Determine the temperature and total enthalpy when the heating is completed.
Answer: The temperature is [tex]21.6^{o}C[/tex] and total enthalpy when the heating is completed is 300 kJ.
Explanation:
Given: Mass = 10 kg
Volume = 14 L
Final pressure = 600 K
First, convert volume from L to [tex]m^{3}/kg[/tex] as follows.
[tex]v_{1} = \frac{14 \times 10^{-3}}{10}\\= 0.0014 m^{3}/kg[/tex]
According to the R-134a tables at 300 kPa and [tex]0.0014 m^{3}/kg[/tex].
[tex]h_{1}[/tex] = 54.6 kJ/kg
[tex]T_{sat}[/tex] = 0.7 C
[tex]u_{1}[/tex] = 54.1 kJ/kg
Now, at the state 2 [tex]p_{2}[/tex] = 600 kPa and [tex]v_{2} = v_{1} = 0.0014 m^{3}/kg[/tex]
This means that the final temperature at state 2 is [tex]T_{2} = T_{sat} = 21.6^{o}C[/tex]
Hence, the change in enthalpy is calculated as follows.
[tex]\Delta H = m(h_{2} - h_{1})\\= 10(84.6 - 54.6)\\= 300 kJ[/tex]
The first law is applied to transfer the heat transfer as follows.
[tex]Q = m(u_{2} - u_{1})\\= 10(83.8 - 54.1) kJ\\= 297 kJ[/tex]
Thus, we can conclude that the temperature is [tex]21.6^{o}C[/tex] and total enthalpy when the heating is completed is 300 kJ.
For the reaction represented by the equation 2H2 + O2→ 2H2O, how many grams of water can be produced from 6.0 grams of O2?
Answer:
a. 6 grams
b. 108 grams
c. 2 grams
d. 54 grams
What are the safety procedures for nuclear accidents nowadays?
Explanation:
Take shelter in a hard wall building
Close doors and windows cut off ventilation
pH & POH
What is the pH of Barq's Root Beer with a (H+] of 9.25 x 10-5 M?
a) 4.0
b) -4.0
c) 10.0 d) 0.000095
Answer:
4.0Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ { H}^{+}][/tex]
From the question we have
[tex]ph = - log(9.25 \times {10}^{ - 5} ) \\ = 4.03385[/tex]
We have the final answer as
4.0Hope this helps you
Assume that your empty crucible weighs 15.98 g, and the crucible plus the sodium bicarbonate sample weighs 18.56 g. After the first heating, your crucible and contents weighs 17.51 g. After the second heating, your crucible and contents weighs 17.50 g.What is the theoretical yield of sodium carbonate
The question is incomplete, the complete question is;
Assume that your empty crucible weighs 15.98 g, and the crucible plus the sodium bicarbonate sample weighs 18.56 g. After the first heating, your crucible and contents weighs 17.51 g. After the second heating, your crucible and contents weighs 17.50 g.
What is the theoretical yield of sodium carbonate?
What is the experimental yield of sodium carbonate?
What is the percent yield for sodium carbonate?
Which errors could cause your percent yield to be falsely high, or even over 100%?
Answer:
See Explanation
Explanation:
We have to note that water is driven away after the second heating hence we are concerned with the weight of the pure dry product.
Hence;
From the reaction;
2 NaHCO3 → Na2CO3(s) + H2O(l) + CO2(g)
Number of moles of sodium bicarbonate = 18.56 - 15.98 = 2.58 g/87 g/mol
= 0.0297 moles
2 moles of sodium bicarbonate yields 1 mole of sodium carbonate
0.0297 moles of 0.015 moles sodium bicarbonate yields 0.0297 * 1/2 = 0.015 moles
Theoretical yield of sodium carbonate = 0.015 moles * 106 g/mol = 1.59 g
Experimental yield of sodium bicarbonate = 17.50 g - 15.98 g = 1.52 g
% yield = experimental yield/Theoretical yield * 100
% yield = 1.52/1.59 * 100
% yield = 96%
The percent yield may exceed 100% if the water and CO2 are not removed from the system by heating the solid product to a constant mass.
8x10^-200 in significant figures PLEASE IVE BEEN STUCK ON IT FOR 2 HOURS
If a sample has a mass of 1.25 x 102 g and a volume of 51 mL, what is its density?
Answer:
2.45 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]d = \frac{m}{v} \\ [/tex]
We have
[tex]d = \frac{1.25 \times {10}^{2} }{51} \\ = 2.45098..[/tex]
We have the final answer as
2.45 g/mLHope this helps you
If 6.75 g of NaOH are dissolved in 50.00 g of water and the temperature increases from 20.5°C to 47.8 °C.
a. Is this an example of an endothermic or exothermic reaction?
b. What is the q for the reaction? (Remember since the NaOH dissolves in water add the masses to get the m)
c. How many moles of NaOH are dissolved?
d. What is the ΔH for the reaction?
Explanation:
Have a good luck with ur exam
The MO diagram of CN is similar to N2. Based on the molecular orbital energy-level diagram of CN, which of the following statements are correct?
i. The CN bond order is 2.
ii. CN is diamagnetic.
iii. The bond enthalpy in CN- ion is higher than CN.
iv. CN has longer bond length than CN-
answer choices:
a. ii, iv
b. iii, iv
c. i, iii
d. i, ii
e. i, iv
Answer:
Nitrogen molecule (N2)
The electronic configuration of nitrogen (Z=7) = 1s2 2s2 2px12py12pz1.
The total number of electrons present in the nitrogen molecule (N2) is 14.
In order to maximize energy, these 14 electrons can be accommodated in the different molecular orbitals.
N2: KK'(σ2s)2 (σ*2s)2 (π2Px)2 (π2py)2 (σ2pz)2
Here (σ1s)2 (σ*1s)2 part of the configuration is abbreviated as KK’, which denotes the K shells of the two atoms. In calculating bond order, we can ignore KK’, as it includes two bonding and two antibonding electrons.
The bond order of N2can be calculated as follows:
Here, Nb = 10 and Na = 4
Bond order = (Nb−Na) /2
B.O = (10−4)/2
B.O = 3
So your answer should be C3.
Observe: Click Reset (). The electrons in the outermost orbit, called valence electrons, help to create chemical bonds. Create a lithium atom (3 protons, 4 neutrons, 3 electrons). How many valence electrons are in a neutral lithium atom?
Answer:
There is one valence electron in a neutral lithium atom.
Explanation:
The number of valence electrons in a neutral lithium atom is equal to one.
What is a valence electron?Valence electrons can be described as the electrons filling the outermost shell of an atom while the electrons in the inner shell of an atom are known as core electrons. Lewis structures are used to determine the number of valence electrons and know the types of chemical bonds.
Valence electrons of an atom can be filled in the same or different orbitals and these electrons are responsible for the interaction between atoms and cause the formation of chemical bonds.
Only electrons occupied in the outermost shell can participate in the formation of a bond or a molecule and are responsible for the reactivity of the element.
The number of electrons in the neutral atom of lithium is 3. There is only one electron present on the outermost shell 2s-orbital.
Learn more about valence electrons, here:
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Brainiest if you are correct and this is a Test I just need help on the last one.
Answer:
Explanation
i k the ansewer
What occurs when potassium reacts with chlorine to form
potassium chloride?
1.
Electrons are shared and the bonding is ionic.
2.
Electrons are shared and the bonding is covalent.
3.
Electrons are transferred and the bonding is ionic.
4.
Electrons are transferred and the bonding is covalent.
Answer:
3
Explanation:
potassium is a highly electropositive metal with one electron for bonding, it reacts with a highly electro negative non metal like chlorine to give an electrovalent or ionic bonding
A mixture contains 5.0 g of He, 1.0 g of Ar, and 3.5 g of Ne. Calculate the partial pressure of each gas in the mixture at STP and total pressure of mixture.
Answer:
Total pressure of the mixture = 1 atm
Partial pressure of He = 0.863 atm
Partial pressure of Ar = 0.0173 atm
Partial pressure of Ne = 0.1197 atm
We confirm that the sum of partial pressure of each gas valu
Explanation:
STP conditions are:
1 atm of pressure and
273K of T°
We can also say that those value reffers to 1 mol.
We determine the moles of each:
5 g . 1mol / 4g = 1.25 moles of He
1g . 1mol / 39.9 g = 0.0250 moles of Ar
3.5g . 1mol / 20.18 g = 0.173 moles of Ne
Total pressure of a mixture can be obtained from the Ideal Gases Law.
P . V = n . R . T
Total moles: 1.25 + 0.025 + 0.173 = 1.448 moles
But now, we need the volume. We know that 1 mol is contained at 22.4L at STP.
1.448 mol . 22.4L / 1 mol = 32.4 L
That's the volume for our mixture. We replace:
32.4 L . P = 1.448 mol . 0.082 . 273K
P = (1.448 mol . 0.082 . 273K) / 32.4L = 1 atm
Now we can obtained the partial pressure of each gas from mole fraction
Mol of gas / Total pressure = Partial pressure of gas / Total pressure
Partial pressure of He = (1.25 / 1.448) . 1 atm = 0.863 atm
Partial pressure of Ar = (0.025 / 1.448) . 1 atm = 0.0173 atm
We know that sum of partial pressure is 1 - (Mole fraction He + Mole fr. Ar)
Partial pressure of Ne = 1 - (0.863 + 0.0173) = 0.1197 atm
We confirm that the sum of partial pressure of each gas values the total pressure of the mixture: 0.863 + 0.0173 + 0.1197 = 1
If 330 grams of potassium chloride, KCl, is dissolved in enough water to make 2.53 liters of solution, what is the concentration (in molarity) of the solution?
could you theoretically cook methamphetamine? just wonderkng.
light energy travels in
Light energy travels in the form of waves.
BRAINIEST AND POINTS
Which option below accurately describes the relationship between frequency and wavelength?
A. The higher the frequency the shorter the wavelength.
B. The lower the frequency the shorter the wavelength.
Answer:
Hi, there your answer is A. As the frequency of a wave increases, the shorter its wavelength is.
Explanation:
When frequency increases, wavelength decreases.
Hope this Helps :)
g If 50.0 mL of a 0.75 M acetic acid solution is titrated with 1.0 M sodium hydroxide, what is the pH after 10.0 mL of NaOH have been added
Answer:
pH = 2.66
Explanation:
Acetic Acid + NaOH → Sodium Acetate + H₂OFirst we calculate the number of moles of each reactant, using the given volumes and concentrations:
0.75 M Acetic acid * 50.0 mL = 37.5 mmol acetic acid1.0 M NaOH * 10.0 mL = 10 mmol NaOHWe calculate how many acetic acid moles remain after the reaction:
37.5 mmol - 10 mmol = 27.5 mmol acetic acidWe now calculate the molar concentration of acetic acid after the reaction:
27.5 mmol / (50.0 mL + 10.0 mL) = 0.458 M
Then we calculate [H⁺], using the following formula for weak acid solutions:
[H⁺] = [tex]\sqrt{C*Ka}=\sqrt{0.458M*1.76x10^{-5}}[/tex][H⁺] = 0.0028Finally we calculate the pH:
pH = -log[H⁺]pH = 2.66A sample of sulfur dioxide (SO2) is initially at a temperature of
155°C, a volume of 25 L, and a pressure of 950 mm Hg. If the
volume changes to 30 L and the temperature increases to 200°C,
what is the new pressure? Show your work.
Show your work. Don't forget to convert °C to Kelvin.
Answer:
874.89 mmHg
Explanation:
Using the combined gas law equation as follows:
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (mmHg)
P2 = final pressure (mmHg)
V1 = initial volume (L)
V2 = final volume (L)
T1 = initial temperature (K)
T2 = final temperature (K)
Based on the information provided in this question;
P1 = 950 mm Hg
P2 = ?
V1 = 25 L
V2 = 30 L
T1 = 155°C = 155 + 273 = 428K
T2 = 200°C = 200 + 273 = 473K
Using P1V1/T1 = P2V2/T2
950 × 25/428 = P2 × 30/473
23750/428 = 30P2/473
55.49 = 0.063P2
P2 = 55.49 ÷ 0.063
P2 = 874.89 mmHg
ill give brainliest :D
how many grams of kcl are produced from 11.5 grams?
Answer:
approximately 15.1 grams.
Explanation:
The key to chemistry is to change everything to moles. Then when you have the answer in moles change the answer back to grams, liters, or whatever you want.
change 25 grams of potassium chlorate to moles.
calculate the gram molecular mass of potassium chlorate.
Chlorate is Cl with 3 oxygens. ate = saturated. Chlorine has seven valance electrons when it is saturated six of these electrons are used by oxygen ( 2 electrons per oxygen) leaving only 1 electron.
1 K x 39 grams/mole
+1 Cl x 35.4 grams/ mole
+3 O x 16 grams/ mole
= 122.4 grams / mole Potassium Chlorate
25
122.4
= moles.
2.05 moles of Potassium Chlorate.
There is a 1:1 mole ratio. 1 mole of Potassium Chlorate will produce 1 mole of Potassium Chloride.
2.05 moles of Potassium Chlorate will produce 2.05 moles of Potassium Chloride.
Find the gram molecular mass of Potassium Chloride.
1 K x 39 = 39
+1 Cl x 35.4 = 35.4
= 74.4 grams / mole.
2.05 moles x 74.4 grams/ mole = 15.2 grams
Answer:
idont know nalimotan ko hhhh...
Look at the table of dissociation constants for some acids.
Acid Ka Acetic acid 18 x 10-6 1.2 x 10-2 Chlorous acid Nitrous acid 4.0 x 10 -4 Propionic acid 1.3 x 10-5
Which of these is the strongest acid?
acetic acid
chlorous acid
nitrous acid
propionic acid
*Answer is B*
Answer:
chlorous acid
Explanation:
The acidic equilibrium of weak acids, HX, occurs as follows:
HX ⇄ H+ + X-
Where Ka is written as:
Ka = [H+] [X-] / [HX]
The strongest acid is the acid that produce more H+. The acid with the higher Ka is the acid that produce more [H+] and is, thus, the strongest acid.
The higher Ka is the Ka of chlorus acid = 1.2x10-2
Right answer is:
chlorous acidAnswer:
chlorous acid :)
Explanation:
BRAINIEST AND 10 POINTS
Which option below is the correct order of the colors of light in the visible portion of the electromagnetic spectrum if we place them in order from HIGHEST to LOWEST frequency.
A. Red, Orange, Yellow, Green, Blue, Indigo, Violet.
B. Violet, Indigo, Blue, Green, Yellow, Orange, Red
C. Red, Blue, Yellow, Ingido, Violet, Orange, Green
g 1. Write a balanced chemical equation, including physical state symbols, for the decomposition of solid sodium azide (NaN3) into solid sodium and gaseous dinitrogen.
Answer: A balanced chemical equation, including physical state symbols, for the decomposition of solid sodium azide ([tex]NaN_{3}[/tex]) into solid sodium and gaseous dinitrogen is [tex]2NaN_{3}(s) \rightarrow 2Na(s) + 3N_{2}(g)[/tex].
Explanation:
A chemical equation which contains same number of atoms on both reactant and product side is called a balanced chemical equation.
For example, [tex]NaN_{3}(s) \rightarrow Na(s) + N_{2}(g)[/tex]
Here, number of atoms present on reactant side are as follows.
Na = 1N = 3Number of atoms present on product side are as follows.
Na = 1N = 2To balance this equation, multiply [tex]NaN_{3}[/tex] by 2 on reactant side. Also, multiply Na by 2 and [tex]N_{2}[/tex] by 3 on product side.
The equation will be rewritten as follows.
[tex]2NaN_{3}(s) \rightarrow 2Na(s) + 3N_{2}(g)[/tex]
This equation contains same number of atoms on both reactant and product side. Hence, this equation is now balanced.
The symbols (s) and (g) depicts the physical state of substances present in the equation as solid and gas.
Thus, we can conclude that balanced chemical equation, including physical state symbols, for the decomposition of solid sodium azide ([tex]NaN_{3}[/tex]) into solid sodium and gaseous dinitrogen is [tex]2NaN_{3}(s) \rightarrow 2Na(s) + 3N_{2}(g)[/tex].
please help me quickly ????
Calculate the equilibrium solubility of silver arsenate
(Ksp = 6 * 10-23) in a solution that buffered to a pH of :
a) 3
b) 6
c) 9
For H3ASO4
Ka1 = 5 * 10-3
Ka2 = 1.1 * 10-7
Ka3 = 3.2 * 10-12
Answer:
sorry don't know the answer!!!
How many sides does a dodecahedron have?
Answer:
the correct answer is 12 sides (:
Explanation:
What is the chemical formula for ammonium sulfide?
(NH4)2S
2.
(NH4)2SO3
3.
(NH4)2SO4
4.
(NH4)2S203
Answer:
Sulphide ion(S-²) has a -2 charge
Ammonium (NH4+¹) has a +1 charge
When Exchange of Radicals Occur..
The compound formed is
(NH4)2S.
OPTION A IS YOUR ANSWER!
Answer:
NH4)2S
So it is A
Explanation:
Can someone tell me what I fill in the blanks
Answer:
circulatory and excretory
How many grams of glucose (CH20) can corn grown in central Illinois make using 5.0 L of carbon dioxide gas and 2.5 L of water at 32 °C and 750 mmHg?
ground to two decimal values)
Answer:
5.9 g
Explanation:
Step 1: Write the balanced reaction for the photosynthesis
6 CO₂ + 6 H₂O ⇒ C₆H₁₂O₆ + 6 O₂
Step 2: Calculate the moles of CO₂
We have 5.0 L of CO₂ at 32 °C (305 K) and 750 mmHg. We can calculate the moles of CO₂ using the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 750 mmHg × 5.0 L/(62.4 mmHg.L/mol.K) × 305 K = 0.20 mol
Step 3: Calculate the moles of C₆H₁₂O₆ produced from 0.20 moles of CO₂
The molar ratio of CO₂ to C₆H₁₂O₆ is 6:1. The moles of C₆H₁₂O₆ produced are 1/6 × 0.20 mol = 0.033 mol
Step 4: Calculate the mass corresponding to 0.033 moles of C₆H₁₂O₆
The molar mass of C₆H₁₂O₆ is 180.16 g/mol.
0.033 mol × 180.16 g/mol = 5.9 g