Answer:
219.15 grams
Explanation:
What is the mass of 3.75 moles of NaCI? ( Na= 22.99g/mol, CI= 35.45 g/mol)
Mole of Na = 22.99g
Mole of Cl = 35.45g
For NaCl we have ratio of 1:1, so we have 1 Na for every Cl
So we just add the two together to get the molar mass of NaCl which is
22.99 + 35.45 = 58.44g/mol
And we know we have 3.75 moles of NaCl so we multiply that by the molar mass of NaCl to get our answer
3.75 x 58.44 = 219.15grams
The type of nuclear decay an unstable nucleus will undergo depends on its ratio of neutrons to protons. The radioisotope cobalt-65 has a ratio of neutrons to protons of 1.41, which is too high for a nucleus of this size. What nuclear changes could reduce this ratio
Answer:
Explanation:
In cobalt - 65 ,
no of protons is 27 ( p )
no of neutron = 65 - 27 ( n )
= 38
n / p ratio
= 38 / 27
= 1.41
If case of emission of alpha particle
no of proton p = 27 - 2 = 25
no of neutrons = 38 - 2 = 36
n / p ratio = 36 / 25
= 1.44
So it increases
In case of emission of beta particle
No of neutron n = 38 - 1 = 37
No of proton = 27 + 1 = 28
n / p ratio = 37 / 28
= 1.32
Hence ratio decreases.
Hence beta ray decay will result in decrease in n / p ratio.
Hi I have a lab for Chemistry I am struggling with. I have to do calculations given the following information
1. Mass of evaporating dish plus sample 26.57 g
2. Mass of evaporating dish 24.29 g
3. Mass of evaporating plus NaCl 68.66 g
4. Mass of evaporating dish 67.84 g
5. Mass of filter paper plus sand 37.69 g
6. Mass of filter paper 36.34 g
CALCULATIONS AND CONCLUSIONS
1. Calculate the mass of unknown mixture g
2. Calculate the mass of NaCl recovered g
3. Calculate the mass of sand recovered g
4. Calculate the percentage of NaCl in your unknown mixture %
5. Calculate the percent sand in your unknown mixture %
6. Calculate the total mass of sand and salt recovered g
7. Calculate the percent recovery of the components %
Answer:
1. 2.28 g
2. 0.82 g
3. 1.35 g
4. 36 %
5. 59 %
6. 2.17 g
7. 95 %
Explanation:
Hello,
1. In this case, the mass of the unknown mixture is obtained by subtracting the mass of the dish plus sample and the mass of the dish:
m = 26.57 g- 24.29 g = 2.28 g
2. In this case, the mass of the NaCl recovered is obtained by subtracting the mass of the dish plus NaCl and the mass of the dish:
m = 68.66 g- 67.84 g = 0.82 g
3. In this case, the mass of the sand recovered is obtained by subtracting the mass of the filter paper plus sand and the mass of the filter paper:
m = 37.69 g- 36.34 g = 1.35 g
4. The percentage of NaCl is computed by considering its mass and the mass of the unknown mixture:
% NaCl = 0.82 g / 2.28 g * 100 % = 36 %
5. The percentage of sand is computed by considering its mass and the mass of the unknown mixture:
% sand = 1.35 g / 2.28 g * 100 % = 59 %
6. Here,we have to add the mass of NaCl and sand:
m = 0.82 g + 1.35 g = 2.17 g
7. Finally, the percent recovery is obtained by diving the total recovered mass by the total obtained mass of the mixture:
% recovery = 2.17 g / 2.28 g * 100 % = 95 %
Best regards.
A student dissolved 5.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution. He took 4.00 mL of the stock solution and then diluted it with water to give 275. mL of a final solution. How many grams of NO3- ion are there in the final solution?
Answer:
0.136g
Explanation:
A student dissolved 5.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution. He took 4.00 mL of the stock solution and then diluted it with water to give 275. mL of a final solution. How many grams of NO3- ion are there in the final solution?
[tex]Co(NO_3)_2(aq)\rightarrow Co^{2+}(aq)+2NO_3^{-}(aq)[/tex]
Initial mole of Co(NO3)2 [tex]=\frac{mass}{molar mass}[/tex]
[tex]=\frac{5.00}{182.94} \\\\=0.02733mol[/tex]
Mole of Co(NO3)2 in final solution
[tex]=\frac{4.00}{100}\times 0.02733\\\\=0.04\times 0.02733\\\\= 0.001093mol[/tex]
Mole of NO3- in final solution = 2 x Mole of Co(NO3)2
[tex]=2\times 0.001093\\\\=0.002186mol[/tex]
Mass of NO3- in final solution is mole x Molar mass of NO3
[tex]=0.002186\times62.01\\\\=0.136g[/tex]
The final solution contains 0.24 g of nitrate ion.
Number of moles of Co(NO3)2 = 5.00 g/183 g/mol = 0.027 moles
Number of moles = concentration × volume
concentration = Number of moles /volume
Volume of solution = 100 mL or 0.1 L
concentration = 0.027 moles/0.1 L = 0.27 M
Using the dilution formula;
C1V1 = C2V2
C1 = 0.27 M
V1 = 4.00 mL
C2 = ?
V2 = 275. mL
C2 = C1V1/V2
C2 = 0.27 × 4.00/ 275
C2 = 0.0039 M
Number of moles of NO3- ion in Co(NO3)2 = 0.0039 M × 62 g/mol = 0.24 g
Learn more: https://brainly.com/question/1340582
The following data show the rate constant of a reaction measured at several different temperatures. Temperature (K) Rate Constant (1/s) 310 0.194 320 0.554 330 1.48 340 3.74 350 8.97 Part APart complete Use an Arrhenius plot to determine the activation barrier for the reaction. Express your answer using three significant figures. Ea
Complete Question
The complete question is shown on the first uploaded image
Answer:
Part A
activation barrier for the reaction [tex]E_a = 84 .0 \ KJ/mol[/tex]
Part B
The frequency plot is [tex]A = 2.4*10^{13} s^{-1}[/tex]
Explanation:
From the question we are told that
at [tex]T_1 = 300 \ K[/tex] [tex]k_1 = 5.70 *10^{-2}[/tex]
and at [tex]T_2 = 310 \ K[/tex] [tex]k_2 = 0.169[/tex]
The Arrhenius plot is mathematically represented as
[tex]ln [\frac{k_2}{k_1} ] = \frac{E_a}{R} [\frac{1}{T_1} - \frac{1}{T_2} ][/tex]
Where [tex]E_a[/tex] is the activation barrier for the reaction
R is the gas constant with a value of [tex]R = 8.314*10^{-3} KJ/mol \cdot K[/tex]
Substituting values
[tex]ln [\frac{0.169}{6*10^-2{}} ] = \frac{E_a}{8.314*10^{-3}} [\frac{1}{300} - \frac{1}{310} ][/tex]
=> [tex]E_a = 84 .0 \ KJ/mol[/tex]
The Arrhenius plot can also be mathematically represented as
[tex]k = A * e^{-\frac{E_a}{RT} }[/tex]
Here we can use any value of k from the data table with there corresponding temperature let take [tex]k_2 \ and \ T_2[/tex]
So substituting values
[tex]0.169 = A e ^{- \frac{84.0}{8.314*10^{-3} * 310} }[/tex]
=> [tex]A = 2.4*10^{13} s^{-1}[/tex]
Calculate the amount of ATP in kg that is turned over by a resting human every 24 hours. Assume that a typical human contains ~50g of ATP (Mr 505) and consumes ~8000 kJ of energy in food each day. The energy stored in the terminal anhydride bond of ATP under standard conditions is 30.6 kJmol-1. Assume also that the dietary energy is channeled through ATP with an energy transfer efficiency of ~50%.
Answer:
The correct answer is 66.35 kilograms.
Explanation:
Based on the data given in the question, the energy consumed by the body of a human being is 50%. Based on the given data, the energy consumed in a day is 8000 kJ, 50 percent is the energy transfer efficiency. Thus, the consumption of total energy is 4000 kJ, and for the transformation of ADP to ATP, the energy involved is 30.6 kJ per mole.
Hence, the total ATP produced in the process is,
ATP = 4000 kJ / 30.6 kJ/mol
= 130.7189 mol.
Thus, with the energy transfer efficiency of 50 percent, the total moles of ATP produced is 130.7 mol.
The mass of ATP can be calculated by using the formula,
moles = mass/molecular mass
The molecular mass of ATP is 507.18 g per mol
Now by putting the values we get,
mass of ATP = 130.7189 mol * 507.18 g/mol
= 66298.011 g or 66.298 kg
It is mentioned that human comprise 50 g of ATP or 0.05 kg of ATP. Therefore, the sum of the available ATP will be.
= Total production of ATP + Total ATP available
= 66.298 kg + 0.05 kg
= 66.348 kg
Hence, the sum of the ATP that is turned over by a resting human in a day is 66.35 kg.
What is the molar mass of CH2O2 ? ( C= 12.01 g/mol, H=1.008 g/mol, O=16.00)
Answer:
Molar Mass of CH2O2 is 46.026
Explanation:
What is the molar mass of CH2O2 ? ( C= 12.01 g/mol, H=1.008 g/mol, O=16.00)
C = 12.01g/mol
H = 1.008g/mol
O = 16g/mol
CH2O2 = 12.01+1.008x2+16x2 = 46.026g/mole
How many significant figures are in 382.90?
Answer:
5
Explanation:
Answer:
5
Explanation:
What is in period 6 group 8
Answer:
Osmium
Explanation:
If you take a look at the attached image of a periodic table below, you will see that the element in the 6th period and 8th group is Osmium. Hope this helps!
The decomposition of Ca(OH)2(s) intoCaO(s) and H2O(g) at constant pressure requires the addition of 109 kJ of heat per mole of Ca(OH)2.
A. Write a balanced thermochemical equation for the reaction.
B. Draw an enthalpy diagram for the reaction, showing the activation energy, Ea, and the enthalpy change for the reaction.
Answer:
A. Ca(OH)2 ----> CaO + H2O; ∆H = +109KJ
B. Check attached document below for the enthalpy diagram
Explanation:
A thermochemical equation is a balanced chemical equation in which enthalpy change is variable. It tells about the nature of the reaction.
Enthalpy change is the difference between the heat content of the products and reactants in a thermochemical equation.
∆H is negative for an exothermic reaction (a reaction where heat is given out), while it is positive for an endothermic reaction ( a reaction in which heat is added).
The activation energy, Ea, is the minimum amount of energy reactant particles must possess in order for a reaction to proceed towards product formation.
As per the decomposition of the Ca(OH) 2 and the CaO the constant pressure needs to be added of the 109KJ.
The balance thermochemical equation for the reaction is expressed as Ca(OH)2 ----> Ca O + H2O; ∆H = +109KJThe diagram for the reaction and the activation energy is given above.Learn more about decomposition.
brainly.com/question/14797703.
How to treat stream water for drinking
Answer:
Explanation:
Boiling.
Use water filter
Use Ultraviolet Light.
Use chlorine drops
I would recomade boiling as the main
because its the easiest and cheapest Or water filter if you have one
Clues about the history of the earth have been obtained from the study of
fossil fuels
rain forest materials
soll samples
O synthetic plastics
Answer: Fossil fuels
Explanation:
Fossil fuels such as petroleum, oil, and natural gas, are non-renewable energy resources which are formed from the remains of prehistoric ancient plants and animals beneath layers of rock of the earth surface.
By analyzing and studying fossil fuels using Radiocarbon analyses by archaeologists, earth scientists etc, Information about the history of the earth can be obtained from the decomposition of dead organisms present in fossil fuels.
why are the products of light reaction of photosythesis important
Answer: light reaction produces oxygen and water as we know the general importance of oxygen and water they are useful for organism to survive if plants do not produce oxygen then how could we get oxygen from the environment
Explain why both square planar and tetrahedral complexes have coordination number=4, and yet square planar complexes can never be chiral while tetrahedral complexes can.
Answer:
The coordination number is 4.
Explanation:
Square planar clusters can be either cis or trans, as they form 180 and 90-degree bond angles. Therefore, a pair of ions may be adjacent (cis) to one another and immediately across (trans) from one another. A square planar molecule could never be simultaneously cis and trans, so because several coordinators are 4. Since linear complexes have only an angle of a bond of 180 degrees, they can not have cis or trans-isomers. In the coordination complex, there is only yet another way possible of bonding the two binding sites to the steel.2 FONS
How does the electric force between two charged particles change if the
distance between them is increased by a factor of 22
A. It increases by a factor of 4.
B. It increases by a factor of 2.
C. It decreases by a factor of 4
O
D. It decreases by a factor of 2.
SUB
Answer:
C. It decreases by a factor of 4
Explanation:
F1 = kq1*q2/r²
F2 = kq1*q2/(2r)² = kq1*q2/(4r²) = kq1*q2/(r²*4) = F1/4
In TLC chromatography of plant pigments, why do different pigments travel up the plate at different rates
When 25ml of sulphuric acid, was titrated with 0.0820 mol/L sodium hydroxide solution the end point was detected (with phenolphthalein) at 22.5ml . Calculate the concentration of sulphuric
acid in mol/L.
Answer:
the concentration of sulphuric acid is 14mol/l
If a solution containing 23.81 g of lead(II) acetate is allowed to react completely with a solution containing 7.410 g of sodium sulfate, how many grams of solid precipitate will be formed g
Answer:
The correct answer is 15.80 grams.
Explanation:
The reaction taking place in the given question,
Pb(CH₃COO)₂ + Na₂SO₄ ⇒ PbSO₄ + 2NaCH₃COO
The number of moles can be calculated by using the formula,
n = weight / molecular mass
Based on the given question, the weight of lead (II) acetate is 23.81 grams and the weight of sodium sulfate is 7.410 grams.
The number of moles of Pb(CH₃COO)₂ is,
n = 23.81 g / 325.29 g/mol = 0.0732 moles
The number of moles of Na₂SO₄ is,
n = 7.410 g / 142.04 g/mol = 0.0521 moles
As one mole of lead (II) acetate needs one mole of sodium sulfate. Therefore, 0.0732 moles of lead (II) acetate needs 0.0732 moles of sodium sulfate.
However, as sodium sulfate is less, that is, 0.0521, therefore, Na₂SO₄ is a limiting reactant.
One mole of sodium sulfate produces one mole of PbSO₄. So, 0.0521 moles of Na₂SO₄ produces 0.0521 moles of PbSO₄.
Now the mass of PbSO₄ is,
mass = moles × molecular mass
mass = 0.0521 × 303.26 g/mol
mass = 15.80 grams.
A microwave has a wavelength of 0.028 m. What us this wavelength in scientific notation
Answer:
2.8 times 10^ -2
Explanation:
scientific notation is supposed to be a number between 1 and 10
the decimal point moves 2 to the right in order to get 2.8 which makes the exponent negative
What mass of carbon dioxide is produced from the complete combustion of 7.30×10−3 g of methane?
URGENT!! This is timed, PLEASE HELP!
Nitrogen gas can be prepared by passing gaseous ammonia over solid copper (II) oxide at high temperatures, as described by the following balanced equation:
2 NH3(g) + 3 CuO(s) → 1N2(g) + 3 Cu(s) + 3 H2O(g)
How many grams of N2 are formed when 120.51 g of NH3 are reacted with excess CuO?
(Please explain using steps and show the whole process. Make sure the answer is in sig figs)
Answer:
99.24 gm of nitrogen .
Explanation:
molecular weight of ammonia = 17 , molecular weight of nitrogen = 28.
2 NH₃(g) + 3 CuO(s) → 1N₂(g) + 3 Cu(s) + 3 H₂O(g)
2 x 17 gm 28 gm
( 34 gm )
34 gm of ammonia forms 28 gms of nitrogen
1 gm of ammonia forms 28 / 34 gms of nitrogen
120.51 gn of ammonia forms 28 x 120.51 / 34 gms of nitrogen
28 x 120.51 / 34 gms
= 99.24 gms of nitrogen will be formed .
how do you create flu vaccine,
Answer:
Explanation:
The fluid containing virus is harvested from the eggs. For inactivated influenza vaccines (i.e., flu shots), the vaccine viruses are then inactivated (killed), and the virus antigen is purified. The manufacturing process continues with quality testing, filling and distribution.
The realization that guanine and thymine base pair to cysteine and adenine, respectively, through their keto-like tautomeric forms has ultimately led to which types of technologies seen in popular TV shows like CSI and Law and Order?
a. DNA sequencing and profiling
b. Flexible display monitors
c. Smart phones
d. Police cars
Answer:
The correct answer to the following question will be Option A (DNA sequencing and profiling).
Explanation:
It is indeed a procedure through which a specific DNA sequence named as the profile is chosen to take from either a sample or perhaps a survey. For humans, much more of the DNA sequence will be the same, although only different regions differ in sequencing, such locations are considered polymorphic. The disparity between individuals regardless of such a particular process is named as polymorphisms, and then this method is being used in the detection of murders, parental conflicts, etc.The other three situations aren't connected to the situation in question. That option 1 seems to be the right answer.
Please choose one of the choices
Answer:
A. the law of constant composition
Explanation:
The molecules in the container would have the same composition because they would have traded around atoms until an equilibrium was reached with every molecule having 1 Hydrogen and 1 Chlorine.
When 200g of AgNO3 solution mixes with 150 g of NaI solution, 2.93 g of AgI precipitates, and the temperature of the solution rises by 1.34oC. Assume 350 g of solution and a specific heat capacity of 4.184 J/g•oC. Calculate H for the following: Ag+(aq) + I- (aq) → AgI(s)
Answer:
[tex]\Delta H=1962.3J[/tex]
Explanation:
Hello,
In this case, we can compute the change in the solution enthalpy by using the following formula:
[tex]\Delta H=mC\Delta T[/tex]
Whereas the mass of the solution is 350 g, the specific heat capacity is 4.184 J/g °C and the change in the temperature is 1.34 °C, therefore, we obtain:
[tex]\Delta H=350g*4.184\frac{J}{g\°C} *1.34\°C\\\\\Delta H=1962.3J[/tex]
It is important to notice that the mass is just 350 g that is the reacting amount and by means of the law of the conservation of mass, the total mass will remain constant, for that reason we compute the change in the enthalpy as shown above, which is positive due to the temperature raise.
Best regards.
Discuss any give ways by which
the falling moral standards of Ghanaian
youth can be minimised.
Answer:
The falling standards of Ghanaian youths can be minimized by proper upbringing of the children by their parents. The youths should be taught about what is wrong or right and there should be a corresponding reward for those who do good and exceptional in order to encourage others in towing that line and punishment should also be meted out to those who break the law. Mediocrity shouldn’t be celebrated and the elders should lead by example.
These will make the falling standards of Ghanaian youth get reduced.
When researchers need to prepare many reactions for polymerase chain reaction (PCR) amplification, they often create a "master mix" solution. A master mix contains the reagents common to all the planned PCR amplifications, regardless of the target DNA. Making a master mix is a way to minimize the number of pipetting steps.Suppose a researcher needs to PCR amplify seven different genes of interest from different organisms. The researcher prepares a master mix and dispenses it to seven different PCR tubes, one for each gene of interest.Select the PCR components the researcher must add to each of the seven tubes of master mix to selectively amplify each gene of interest.dNTPsMg2+-Mg2+-based bufferprimersDNA polymeraseDNA template
Answer:
The master mix contains the following reagents: dNTPs, DNA Polymerase, PCR buffer and MgCl2.
Explanation:
The DNA templates are the gene fragments to amplify by PCR, thereby they have to be added separately in each tube. Moreover, the primer pairs are specific for each gene, thereby they have to be added separately in each tube.
Deoxynucleotide triphosphates (dNTPs) are the building blocks of the DNA molecules: dGTP, dATP, TTP, and dCTP.
The PCR buffer provides a suitable medium for the activity of the DNA polymerase, often it contains Tris-Hcl and KCl.
MgCl2 is a cofactor for the activity of the DNA Polymerase.
The DNA Polymerase is an enzyme that amplifies DNA by adding nucleotides to the 3' end.
Light travels three-fourths as fast through water as it does through a vacuum.
What is water's index of refraction?
6. To isolate benzoic acid from a bicarbonate solution, it is acidified with concen- trated hydrochloric acid, as in experiment 1. What volume of acid is needed to neutralize the bicarbonate
Answer:
For our assumed experiment; the expected volume of Hcl acid needed to neutralize the bicarbonate is 0.13 mL
Explanation:
We are going attempt this question experimentally.
We know that benzoic acid originate from the relationship between benzene and a carboxylic group. So basically , the functional group of a carboxylic acid (-COOH) joins with a benzene ring(C₆H₆) to form a simple aromatic carboxylic acid known as Benzoic acid. (C₇H₆O₂)
However, it is possible to isolate benzoic acid from a bicarbonate solution in the presence of an acidified concentrated hydrochloric acid.
Let assume that ;
0.20 g of benzoic acid was reacted with 2 mL of a 20% solution of NaHCO₃, the amount of the excess NaHCO₃ can be determined by subtracting the amount of benzoic acid from the amount of NaHCO₃.
Let first calculate the number of moles in 0.20 g of benzoic acid
we know that the standard molar mass of benzoic acid is 122.12 g/mol
number of moles of benzoic acid = mass of benzoic acid/molar mass of benzoic acid =
number of moles of benzoic acid = 0.20/ 122.12
number of moles of benzoic acid = 0.0016 mol
number of moles of bicarbonate solution = mass of bicarbonate solution/ molar mass of bicarbonate solution
number of moles of bicarbonate solution = 0.2/84.00654 g/mol
number of moles of bicarbonate solution = 0.00238 mol
∴
(0.00238 - 0.0016) mol
= 7.8 × 10⁻⁴ mol
Let assume that the concentrated HCl is 12 M
Also. HCl and NaHCO₃ react together at the ratio of 1:1; thus the volume of Hcl acid needed to neutralize the bicarbonate is:
[tex]= ( 7.8 * 10^{-4} \ \ mol )* ( \dfrac{2\ L}{ 12 \ M})*( \dfrac{10^3 \mL}{1 \ L})[/tex]
= 0.13 mL
Thus; for our assumed experiment; the expected volume of Hcl acid needed to neutralize the bicarbonate is 0.13 mL
11. Caproic acid, which is responsible for the foul odor of dirty socks, is composed of C, H, and O atoms. Combustion of a 0.225-g sample of this compound produces 0.512 g CO2 and 0.209 g H2O. (a) What is the empirical formula of caproic acid
Answer:
C3H6O
Explanation:
Step 1:
Data obtained from the question include the following:
Mass of the compound = 0.225g
Mass of CO2 = 0.512g
Mass of H2O = 0.209g
Step 2:
Determination of the masses of carbon, hydrogen and oxygen present in the compound.
This is illustrated below:
For Carbon, C:
Molar mass of CO2 = 12 + (2x16) = 44g/mol
Mass of C in CO2 = 12/44 x 0.512 = 0.1396g
For Hydrogen, H:
Molar mass of H2O = (2x1) + 16 = 18g/mol
Mass of H in H2O = 2/18 x 0.209 = 0.0232g
For Oxygen, O:
Mass of O = 0.225 – (0.1396 + 0.0232)
Mass of O = 0.0622g
Step 3:
Determination of the empirical formula for caprioc acid.
This can be obtain as follow:
C = 0.1396g
H = 0.0232g
O = 0.0622g
Divide by their molar mass
C = 0.1396/12 = 0.0116
H = 0.0232/1 = 0.0232
O = 0.0622/16 = 0.0039
Divide by the smallest
C = 0.0116/0.0039 = 3
H = 0.0232/0.0039 = 6
O = 0.0039/0.0039 = 1
Therefore, the empirical formula for caprioc acid is C3H6O
Give the IUPAC name for the following structure
Answer:
6-metyl-2-heptyne
Explanation:
C-C-C-C-C-C-C hept
2
C-C≡C-C-C-C-C 2-heptyne
C
| 6
C-C≡C-C-C-C-C
6-metyl-2-heptyne
The IUPAC name for the above structure is 6 methyl, hept-2-yne.
What is IUPAC?IUPAC stands for international Union of pure and applied chemistry. It is the body in charge of naming organic chemical compounds.
The naming is is based on a molecule's longest chain of carbons connected by single/double/triple bonds, whether in a continuous chain or in a ring etc.
According to this question, a structure is given. The following applies;
The compound has a triple bond located on the second carbon, hence, belongs to alkyne group. It has seven carbon atoms, hence, is heptyne. The methyl group is on the sixth carbon.Learn more about IUPAC at: https://brainly.com/question/33646537
#SPJ6