Answer:
The correct answer is "142 g".
Explanation:
According to the question,
⇒ [tex]Cu^2+(aq)+2e^ ------> Cu(s)[/tex]
where,
Z = 2
F = 96500c
C = 30 A
t = 4h
= [tex]4\times 60\times 60[/tex]
= [tex]14400 \ sec[/tex]
We know that,
Atomic mass of Cu(M) = 63.5 g/mole
Now,
⇒ [tex]W=\frac{Mct}{ZF}[/tex]
On putting the values, we get
[tex]=\frac{63.5\times 30\times 14400}{2\times 96500}[/tex]
[tex]=\frac{27432000}{193000}[/tex]
[tex]=142 \ g[/tex]
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.
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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.
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A 45-year-old woman comes to a clinic with complaints of morning stiffness in her ankle joints, worse on rising in the morning and improving during the day. Her discomfort is responsive to aspirin. She has also been fatigued and weak. During the last week, she has noticed that her wrist and ankle joints on both sides of her body are also painful and swollen. Blood is drawn to test for rheumatoid factor and antinuclear antibody. Synovial fluid is aspirated and analyzed. Results from analysis of the synovial fluid rule out crystal deposition diseases, such as gout and pseudogout, and no infectious microorganisms are seen.
Required:
a. What can be the possible cause of a false-positive RF assay?
b. Do the patient's clinical symptoms and laboratory results support a diagnosis 5. If so, what diagnosis would be the first choice, and why?
Answer:
In all the patients with rheumatoid arthritis RF is not present. It can also be witnessed in patients with conditions like hepatitis, bacterial endocarditis, and tuberculosis. Some of the reasons that can also produce false-positive results for RF assay are lipemic, hemolyzed, or heavily contaminated serum, other rheumatic diseases like systemic lupus erythematous, reading test results post the specified time of two minutes, and due to some of the chronic infectious diseases like hepatitis, tuberculosis, and syphilis.
b. The symptoms of the oatient like inflammation and pain in joints and the results of the lab indicate that the synovial fluid is drying and formation of crystal is taking place. These are the conditions that suggests the existence of rheumatoid arthritis.
c. In the given case, the first choice diagnosis would be the blood test that would show the presence of anti-CCP antibodies and the drying of synovial fluid. The presence of anti-CCP antibodies results in wear and tear in the joints, thus showing the diseased conditions.
How many isomers are there with the following descriptions? Alcohols with the formula Answer Two Bromoalkanes with the formula Answer
Answer:
Three isomers
Isomer I CH3-CHOH - CH3
Isomer 2 CH2OH-CH2-CH3
Isomer 3 CH3-CH2-CH2OH
Explanation:
Complete question
How many isomers are there with the following descriptions?
a) Alcohol with formula C3H8O
Solution
There are total 3 carbon atoms in this alcohol. Hence, there will be three isomers of Alcohol with formula C3H8O .
The three isomers will comprise of alcohol group (OH) attached to the three carbon atoms one by one.
Isomer I CH3-CHOH - CH3
Isomer 2 CH2OH-CH2-CH3
Isomer 3 CH3-CH2-CH2OH
What is the molality of a solution containing 15 g NaCl dissolved in 50 g of water
Answer:
cdjkekendnekekekeknenwkwkwkwnrnrnrjejjwjwksnsjnrheifjfuufjeenenej
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:
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].
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
4. Suppose in the first part of the experiment you did not heat strong enough to
decompose the potassium chlorate, how would this affect your result?
when you strongly heat the potassium chlorate it leaves oxygen if you'll not heat it strongly to decompose it the oxygen would not release and the compound will remain thermally unstable.
Heating of Potassium Chlorate results into decomposition of Potassium Chloride and Oxygen gas.
When KClO₃ is heated strongly, it breaks down, releasing oxygen gas and leaving behind a thermally stable (i.e., heat-insensitive) solid residue of an ionic potassium compound.
If enough heat is not provided to potassium chlorate then it will not decompose into its substituent products and also some of the potassium chloride product splattered out of the crucible during the heating process.
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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.
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
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...
Brainiest if you are correct and this is a Test I just need help on the last one.
Answer:
Explanation
i k the ansewer
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
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 = 2.665. Calculate the number of molecules of carbon tetrachloride in 0.32 mol of
carbon tetrachloride.
To Find :
The number of molecules of carbon tetrachloride in 0.32 mol of
carbon tetrachloride.
Solution :
We know, 1 mole of any element/compound contains [tex]6.022 \times 10^{23}[/tex] number of atoms/molecules.
So, Number of molecules in 0.32 mol are :
[tex]n = 0.32 \times 6.022 \times 10^{23}\\\\n = 1.93 \times 10^{23}[/tex]
Therefore, number of molecules of carbon tetrachloride in 0.32 mol of
carbon tetrachloride are [tex]1.93 \times 10^{23}[/tex].
A 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
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
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.
best way to hump girls
Answer:
When they're sleeping
Explanation:
After they've been drugged
plz help me asap i need this plz
Why is it sometimes not practical to use to scale models when representing objects in space?
What are 3 different ways we can preserve our ecosystem and what makes your 3 ways effective?
Answer:
1. Stop throwing trash and bottles in lakes because it can have our animals live longer and not have issues
2. Reducing the number of bags you use from the store because they can end up being on the ground and cause plenty of damage around us
3. probably trying not to having fires because there is alot of problems that are happening like the wildfires in californa which is leading to our animals and trees dying
hope this helps
have a good day :)
Explanation:
What are the safety procedures for nuclear accidents nowadays?
Explanation:
Take shelter in a hard wall building
Close doors and windows cut off ventilation
How many sides does a dodecahedron have?
Answer:
the correct answer is 12 sides (:
Explanation:
16. A solution is made by dissolving 25 g of NaCl in enough water to make 1.0 L of solution. Assume the density of the solution is 1.0 g/cm3. Calculate the molarity and molality of the solution.
Answer:
The molarity will be "0.43 M" and molality will be "0.43 m".
Explanation:
Given that:
mass of NaCl,
= 25 g
Volume of solution,
= 1 L
Density of solution,
= 1 gm/cm³
Now,
The weight of solvent will be:
= [tex]Volume\times density[/tex]
= [tex]1\times 1[/tex]
= [tex]1 \ kg[/tex]
The mole of NaCl will be:
= [tex]\frac{mass}{Molar \ mass}[/tex]
= [tex]\frac{25}{58.44}[/tex]
= [tex]0.43[/tex]
hence,
The molarity will be:
= [tex]\frac{number \ of \ mole}{Volume \ of \ solution}[/tex]
= [tex]\frac{0.43}{1}[/tex]
= [tex]0.43 \ M[/tex]
The molality will be:
= [tex]\frac{mole \ of \ solute}{Weight \ of \ solvent}[/tex]
= [tex]\frac{0.43}{1}[/tex]
= [tex]0.43 \ m[/tex]
8x10^-200 in significant figures PLEASE IVE BEEN STUCK ON IT FOR 2 HOURS
4. Which should be done after a volcanic eruption?
A. Go to your neighbor.
B. Prepare your emergency kit.
C. Ignore what is happening around.
D. Stay in the evacuation center until it is safe to return.
5. Which is NOT true about volcanic preparedness?
A. Make a plan.
B. Prepare an emergency kit.
C. Cover your nose with a damp cloth.
D. Do not follow the instructions of the authorities.
Answer:
4. D sounds like the best option.
5. D is the correct answer.
Explanation:
You're Welcome
How many grams are in 0.375 mol LiBr? (MM LiBr=86.85 g/mol)
O 32.6 g
O 0.00315 g
O 0043 g
O 86.8 g
Answer:
32.57g
Explanation:
mass = mole x molar mass
mass of LiBr = 0.375 x 86.85
mass = 32.57g
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
Write out the steps to finding the Empirical Formula.