Answer:
Explanation:
10 mL = 10⁻² L
1 mL of solution contains .0087 x 10⁻² mole of Cu
15 mL of solution will contain .1305 x 10⁻² mole of Cu
.1305 x 10⁻² mole of copper = .1305 x 63.5 x 10⁻² gm of Cu
= .08286 gm
concentration of copper in the ore sample
= .08286 x 100 / .25
= 33 % approx .
Argon-40 undergoes positron emission as shown:
48 Ar X+ IB
Enter the appropriate values for A and Z and the chemical
symbol for X
Answer:
[tex]\frac{40}{18}Ar => \frac{40}{17}Cl + \frac{0}{1}e\\[/tex]
Explanation:
The process of positron emission is better understood by the following reaction:
[tex]\frac{40}{18} Ar[/tex] → + [tex]\frac{40}{17} Cl + \frac{0}{1} e[/tex]. What is Positron emission?Positron emission may be defined as a subordinate type of radioactive decay called which is effectively known as beta decay. Due to this emission, a proton that is present inside a radionuclide nucleus significantly transformed into a neutron while liberating a positron and an electron neutrino.
According to the context of this question, Argon-40 undergoes the process of beta decay. Through which X element is formed which is known as chlorine. The atomic number (Z) of chlorine is 17, while the atomic mass (A) is 40 which is as identical to argon.
Therefore, the appropriate values for A and Z and the chemical symbol for X are 40 and 17 respectively.
To learn more about Positron emission, refer to the link:
https://brainly.com/question/4598666
#SPJ2
A child shivers in a cold rain but does not feel cold, what is the biochemistry behind it
Answer:
Homeostasis is defined as the process by which the internal body system maintains a suitable environment for its proper functions and survival.
When a person temperature drops a signal is sent to the brain which results in a reflex action being observed. The shiver makes the individual warmer and helps in the regulation of the body heat.
Light brings many chemical changes. Can you think of any chemical change brought about by light?
Answer:
MRCORRECT has answered the question
Explanation:
Film photography is another example ofchemical reaction by light. In this example, the chemical compounds coated on the film go through a chemical reaction. ... These plates (usually made of aluminum) are coated with a photosensitive compound consisting of a polymer and a photosensitivechemical system.
which sublevels contain valence electrons in an atom of nitrogen
Sublevel 2s and 2p contains the valence electrons for nitrogen.
A sample of helium gas at room temperature is compressed from 100 cm3 to 20 cm3. Its new pressure is now 30 cm Hg. What was the original pressure of the gas?
Answer:
6 cm Hg
Explanation:
Boyles Law: P1V1=P2V2
(100 mL)(x)=(20 mL)(30 cm Hg)
x = 6 cm Hg
*Text me at 561-400-5105 for private tutoring if interested: I can do homework, labs, and other assignments :)
If a solution has a pOH=12, what is its pH?
Answer:
2
Explanation:
pH+pOH=14
- Hope that helps! Please let me know if you need further explanation.
Answer:
2
Explanation:
Ph+PoH=14
How many grams of californium-254 will remain after 363 days if we
start with 64.0 grams of this substance? The half-life of californium-254
is 60.5 days.
Answer:
1.02 g OF CALIFORNIUM-254 WILL REMAIN AFTER 363 DAYS IF 64 g REACTS WITH HALF LIFE OF 60.5 DAYS.
Explanation:
Half life of a chemical reaction is the time required for a radioactive element to decay to half its original mass.
We will use the formula:
Nt = No (1/2)^t/t1/2 where;
Nt = quantity of substance remaining = unknown
No = original mass of the substance = 64 g
t = time elapsed = 363 days
t1/2 = half life of the substance = 60.5 days
Putting the values into the equation, we have:
Nt = 64 * (1/2)^(363/60.5)
Nt = 64 * (1/2) ^6
Nt = 64 * 0.015625
Nt = 1.0156
The amount of californium-254 remaining after 363 days is approximately 1.02 g
What are 3 stages of the water cycle are
An empty weighing dish has a mass of 1.0041 ± 0.0002 g. After you add dried sodium chloride to the dish, the mass is 3.2933 ± 0.0002 g. You quantitatively transfer the sodium chloride into a 500.00 ± 0.05 mL volumetric flask and dilute to the mark with deionized water. The molar mass of sodium chloride is 58.440 g/mol. What is the absolute error in the concentration of the resulting solution? Report your answer normally to the correct number of significant figures with the correct unit.
Answer:
The correct answer to the following question will be "0.0013%".
Explanation:
The given values are:
Weight of an empty dish = 1.0041 ± 0.0002 g
Weight of dish + sodium chloride (NaCl) = 3.2933 ± 0.0002 g
Weight of NaCl = 2.2892 ± 0.0002 g
Now,
Volume of the solution = 500.00 ± 0.05 ± 0.0002
= 500.00 ± 0.0502 ml
So,
Molarity = [tex]\frac{W \ NaCl}{M \ NaCl} \times \frac{1000}{Volumes \ of \ solution}[/tex]
On putting the values in the above formula, we get
= [tex]\frac{(2.2892\addeq +0.0002)}{58.440}\times \frac{1050}{(500.00+0.0502)}[/tex]
= ([tex]3.917[/tex] ± [tex]0.0002[/tex]) × ([tex]2[/tex] ± [tex]0.0502[/tex])
= ([tex]0.7834[/tex] ± [tex].00001004[/tex])
Now,
Absolute error = [tex]\frac{0.00001004}{0.7834}\times 100[/tex]
= [tex]0.0013[/tex]%
PLEASE help! BRAINLIEST to correct answer!
Answer:
C
Explanation:
Answer:
I think its q
Explanation:
h is the Planck constant, c the speed of light
What is the molar mass of ethanol (C2H60)?
Answer:
46.07 g/mol is the molar mass of ethonal
How many grams is 4.2X10^24 atoms of sulfur?
which would dissolve faster individual salt crystals a big block of salt
Answer:
Table salt (the iodine isn't important) consists of much smaller particles than rock salt and therefore has a much higher ratio of surface area to mass. Since chemical reactions occur at surfaces,the smaller table salt particles will dissolve far more quickly than the larger rock salt.
Explanation:
Answer:
Individual salt crystals
Explanation:
A given quantity of solute dissolves faster when it is ground into small particles than if it is in the form of a large chunk because more surface area is exposed.
Give me a good review if right please.
what numbers go in the blank _Na2Co3+_HCI > _NaCl+H2O+_CO2
Answer: [tex]Na_2CO_3+2HCl\rightarrow 2NaCl+H_2O+CO_2[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation will be:
[tex]1Na_2CO_3+2HCl\rightarrow 2NaCl+H_2O+1CO_2[/tex]
Thus the numbers that go in the blanks are 1, 2, 2, and 1 respectively for [tex]Na_2CO_3[/tex], [tex]HCl[/tex] , [tex]NaCl[/tex] and [tex]CO_2[/tex] respectively.
5) Low iron concentration (as low as 0.02 nM) in the open ocean limits phytoplankton growth. Preconcentration is required to determine such low concentrations. Trace Fe3 from a large volume of seawater is concentrated onto a 1.2 mL chelating resin column, the column is then rinsed with 30 mL of high purity water and eluted with 10 mL of 1.5 M high purity HNO3. a.) For each sample, seawater is passed through the column of 17 h at 10 mL./min. How much is the concentration of Fe3 in the 10 mL of HNO3 eluate increased by this preconcentration procedure
Answer:
Check the explanation
Explanation:
Sample volume V= 10 mL/min x 17 h x 60 min/h / 1000 mL/L = 10.2 L
The concentration is increased
10200 mL (sample volum) / 10 mL (eluted sample) = 1020 times.
57x10-9 M / 1020 = 5.6x10-12 M
1.5 M HNO3 will contain ≤ 2ppm x (1.5M/15.7M ) ≤ 0.190 ppm ≤ 190 ppb
Ignoring this is reagent impurity and calculating for sea water
≤ 190 ppb /1020 = 0.186 ppb = 0.186 x 10-9g/mL = 0.186 x 10-6g/L =
0.186 x 10-6g/L / 56 g/mol = 0.003 x10-6 M = 3 nM
HELP PLEASE ILL GIVE 25 pointsWhich of the following practices could help reduce erosion of water banks? a. buffer strips b. natural fertilizers and pesticides c. decrease in fossil fuel emissions d. all of the above Please select the best answer from the choices provided A B C D
Answer:
A. Buffer strips
Explanation:
The practice that could help reduce erosion of water banks is buffer strips.
What is erosion?Erosion is the action of surface processes that removes soil, rock or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited.
One of the practices that could be used to reduce the effect of erosion is buffer strips.
What buffer strips do is slow and filter storm runoff while helping to hold soil in place.
Learn more on buffer strips here; https://brainly.com/question/26872640
Which characteristic of a substance is considered a chemical property
Answer:
c
Explanation:
the rule of eight chemistry
Answer:
octet rule
Explanation:
It refers to the tendency of atoms to prefer to have eight electrons in the valence shell.
18.35 mL of an HCN solution were titrated with 35.4mL of a 0.268M NaOH solution to reach the equivalence point. What is the molarity of the HCN solution
Answer:
0.517
Explanation:
HCN + NaOH → NaCN + H2O [balanced as written]
(35.4 mL) x (0.268 M NaOH) x (1 mol HCN / 1 mol NaOH) / (18.35 mL HCN) = 0.517 M HCN
Answer: 0.517
Explanation:
Is it true or false?
Answer:
True
Explanation:
Burning waste can lead to air pollution and release of greenhouse gases. Carbon dioxide is one of those gases.
At what temperature will a gas be, if you allow it to expand from its original volume of 756 mL at 65.0 °C to 1.40 L? (hint volume needs to be the same)
Answer:
120.4 gradius Celcius
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
3Fe + 2O2 → Fe3O4 In this reaction, 200 grams of Fe react with 64 grams of O2. How many grams of Fe3O4 will be produced? A 230 grams B 264 grams C 280 grams D 460 grams
Answer:
just did it the answers b
Explanation:
The largest contributed to water pollution is
Answer:
this si from google hope it helps
Explanation:
The Main Causes of Water Pollution in the U.S.
Runoff from Agricultural Operations. Agriculture represents one of the biggest sources of water pollution in the country. ...
Runoff and Nonpoint Source Pollution. ...
Industrial Activities. ...
Leakage from Underground Storage and Piping. ...
Leaking Sewers. ...
Vehicle Emissions. ...
Landfill Leakage. ...
Hazardous Waste.
Answer:
Runoff and Non-point Source Pollution.
Explanation:
it's caused by rainfall or snow-melt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and ground and NPS is it's abbreviation.
The mass of single iridium atom is 3.19*10^-22 grams how many iridium atoms would be in 56.4 milligrams of iridium
What is the molarity of a solution in
which 3.8 moles of sodium chloride
(NaCl) is dissolved in water to a final
volume of 2.5 L?
Answer:
1.52M in NaCl
Explanation:
Molarity = moles solute / volume solution in Liters
=> molarity (M) = 3.8 moles / 2.5 Liters solution = 1.52 molar solution in NaCl
Answer: 1.52
Explanation:
Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolate and measure the amount of gas produced.
Suppose the CO gas evolved by a certain chemical reaction taking place at 55 degree C is collected over water, using an apparatus something like that in the sketch, and the final volume of gas in the collection tube is measured to be 117 ml.
Calculate the mass of CO that is in the collection tube. Round your answer to 2 significant digits. You can make any normal and reasonable assumption about the reaction conditions and the nature of the gases.
Answer:
The correct answer is 0.12 grams.
Explanation:
The mass of carbon monoxide or CO collected in the tube can be determined by using the ideal gas equation, that is, PV = nRT.
Based on the given question, P or the pressure of the gas is given as 1 atm, volume of the gas collected in the tube is 117 ml or 0.117 L.
The number of moles or n can be determined by using the equation, mass/molar mass.
R is the universal gas constant, whose value is 0.0821 L atmK^-1mol^-1, and temperature is 55 degree C or 328 K (55+273).
On putting the values we get:
n = PV/RT
= (1 atm*0.117 L) / (0.0821 L atmK^-1mol^-1 * 328 K)
= 0.0043447 mol
Therefore, mass of CO will be moles * molar mass of CO
= 0.0043447 mol * 28 g/mol
= 0.12 g
The radioactivity due to carbon-14 measured in a piece of a wooden casket from an ancient burial site was found to produce 20 counts per minute from a given sample, whereas the same amount of carbon from a piece of living wood produced 160 counts per minute. The half-life of carbon-14, a beta emitter, is 5730 years. Thus we would estimate the age of the artifact to be about?
Answer:
17202.6 years
Explanation:
Activity of the living sample (Ao) = 160 counts per minute
Activity of the wood sample (A) = 20 counts per minute
Half life of carbon-14 = 5730 years
t= age of the artifact
From;
0.693/t1/2= 2.303/t log Ao/A
Then;
0.693/ 5730= 2.303/t log Ao/A
Substituting values;
0.693/5730= 2.303/t log (160/20)
Then we obtain;
1.209×10^-4 = 2.0798/t
t= 2.0798/1.209×10^-4
Thus;
t= 17202.6 years
Therefore the artifact is 17202.6 years old.
A solution of KOH has a [OH-] concentration of 0.045 M. What is the pOH of the solution? *
1 point
-1.3
1.3
1.1
0.90
what is the answer?
Answer:
[tex]pOH=1.3[/tex]
Explanation:
Hello,
In this case, since pH is computed by knowing the concentration of hydrogen ions, one could compute the pOH by knowing the concentration of the hydroxyl ions as in this case which is 0.045M as shown below:
[tex]pOH=-log([OH^-])=-log([0.045])\\\\pOH=1.3[/tex]
Best regards.
Answer:
The pOH of the 0.045 M solution is 1.3
The second option (1.3) is correct
Explanation:
Step 1: Data given
Concentration [OH-] of KOH is 0.045 M
Step 2: Calculate pOH
pOH = -log[OH-]
pOH = -log (0.045)
pOH = 1.3
The answer:
The pOH of the 0.045 M solution is 1.3
The second option (1.3) is correct
What is the mass defect of a mole of nuclei with 1.8 x 10^15 J/mol binding
energy?
Answer:
2.0 x 10^-2 kg/mol
Explanation:
Two identical light bulbs are connected to a battery in a series circuit.
An ammeter is wired into the circuit at measures a current of the
battery to be 0.5 Amps. The two light bulbs are then wired in parallel.
The ammeter shows that the current:
Answer:
0.10 amps
Explanation:
