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.
The mass of single iridium atom is 3.19*10^-22 grams how many iridium atoms would be in 56.4 milligrams of iridium
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!
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
What did the periodic table help scientists discover?
A. Elements that are radioactive
O B. Elements that are harmful
C. Elements not yet known to exist
D. Elements that no longer exist
There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Option C is correct option.
What is periodic table?
Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.
Periodic table is the best platform to have a look to all elements at once that are arranged in columns and groups mentioning their valencies, electronegativity and Ionisation energy symbols. Thus the option c is correct option.
Learn more about periodic table , here:
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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
If a 1.45 M solution has 2.43 g HCl dissolved, what is the volume of solution? (Change g HCl into mol using molar mass)
Answer: The volume of solution is 0.0459 L
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in L
moles of HCl (solute) = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{2.43g}{36.5g/mol}=0.0666[/tex]
Now put all the given values in the formula of molality, we get
[tex]1.45M=\frac{0.0666}{V_s}[/tex]
[tex]V_s=\frac{0.0666}{1.45}=0.0459[/tex]
Therefore, the volume of solution is 0.0459 L
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:
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
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:
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
Which characteristic of a substance is considered a chemical property
Answer:
c
Explanation:
Living large means we use a lot of energy. What are three ways people use energy in their daily lives?
Answer:
right now we are using energy by online learning on our laptops , air conditioning, and transportation
Explanation:
What parts of the body are tested for rigor Mortis
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:
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
[HCN]=0.09974 M
Kp=7.52
Calculate the partial pressure of HCN ?
Answer:
i don't understand
Explanation:
I'll give you the brainiest please help.
Answer:
c
Explanation:
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
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:
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 are 3 stages of the water cycle are
which sublevels contain valence electrons in an atom of nitrogen
Sublevel 2s and 2p contains the valence electrons for nitrogen.
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 Which state of matter takes both the shape and volume of its container?
liquid
solid
gas
Answer:
gas
Explanation:
If you put gas in anything, it will occupy shape and volume.
Liquid only occupies shape of the container, whereas, solid doesn't occupy shape or volume because it maintains a fixed volume and shape.
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
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H2O(g) + Cl2O(g) ↔ 2 HOCl(g) (a) Initially, 0.0555 mol H2O and 0.0230 mol Cl2O are mixed in a 1.00 L flask. At equilibrium, there is found to be 0.0200 mol of HOCl(g). Calculate the concentrations of H2O(g) and Cl2O(g) at equilibrium. (b) Using your results from part (a), calculate the equilibrium constant, Kc. (c) 1.0 mol pure HOCl is placed in a 2.0 L flask. Use your Kc from part (b) to calculate the equilibrium concentrations of H2O(g) and Cl2O(g).
Answer:
a)
[H₂O] = 0.0455M
[Cl₂O] = 0.0130M
[HOCl] = 0.0200M
b) Kc = 0.676
c) [H₂O] = [Cl₂O] = 0.177M
Explanation:
Based on the reaction:
H₂O(g) + Cl₂O(g) ⇄ 2HOCl(g)
Kc is defined as:
Kc = [HOCl]² / [H₂O][Cl₂O] For molar concentrations in equilibrium
As volume of the flask is 1.00L, the initial molar concentrations of H₂O and Cl₂O is 0.0555M and 0.0230M, respectively.
In equilibrium, the concentrations are:
[H₂O] = 0.0555M - X
[Cl₂O] = 0.0230M - X
[HOCl] = 2x = 0.0200M → X = 0.0100M
Where X is reaction coordinate
a) Concentrations in equilibrium are:
[H₂O] = 0.0455M
[Cl₂O] = 0.0130M
[HOCl] = 0.0200M
b) Replacing in Kc:
Kc = [0.0200]² / [0.0455][0.0130] = 0.676
c) Initial concentration of HOCl is 1.0mol / 2.0L = 0.50M. In equilibrium concentrations are:
[H₂O] = X
[Cl₂O] = X
[HOCl] = 0.50M - 2X
Replacing in Kc formula:
0.676 = [0.50-2X]² / [X][X]
0.676X² = 4X² - 2X + 0.25
0 = 3.324X² - 2X + 0.25
Solving for X:
X = 0.177M
X = 0.425M → False answer, produce negative concentrations.
As X = [H₂O] = [Cl₂O]; equilibrium concentrations of both compounds is 0.177M
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.
What is the molar mass of ethanol (C2H60)?
Answer:
46.07 g/mol is the molar mass of ethonal
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.
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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:
