Answer:
840 J
Explanation:
c ≈ 4200 J / (kg * °C)
m = 20 g = 0,02 kg
[tex]t_{1}[/tex] = 30 °C
[tex]t_{2}[/tex] = 40 °C
The formula is: Q = c * m * ([tex]t_{2} - t_{1}[/tex])
Calculating:
Q = 4200 * 0,02 * (40 - 30) = 840 (J)
1. How many moles are in an 84.2 g sample of aluminum sulfate?
Answer:
0.246 moles
Explanation:
Aluminum Sulfate is an ionic equation so we need to write the equation first with proper charges and subscripts:
Aluminum (Al) has a charge of [3+]. Sulfate (SO4) has a charge of [2-]. The charges need to be swapped to match.The ionic equation therefore is: Al_2(SO4)_3. We need 2 Aluminum's to match with the charge of 3 sulfates.Now that we know the ionic equation, we need to find the molar mass of Al_2(SO4)_3. There's 2 Aluminum's, each weighing 26.98 g/mol. There are 3 sulfates, each sulfate weighs 96.06 g/mol. We need to multiply the number of elements/compounds by their mass to get the total molar mass and then add them up (remember atomic mass = molar mass in g/mol):
(2 Al * 26.98 g/mol) + (3 (SO4) * 96.06 g/mol) = 342.15 g/mol of Al_2(SO4)_3We now know the molar mass of Al_2(SO4)_3 we need to find how many moles of it there are in an 84.2g sample. To do that, we need to do some dimensional analysis:
84.2g Al_2(SO4)_3 * ( 1 mol of Al_2(SO4)_3 / 342.15 g/mol of Al_2(SO4)_3 )The grams of Al_2(SO4)_3 cancel so that we're left with moles of Al_2(SO4)_3 on top:
84.2 * ( 1 mol of Al_2(SO4)_3 / 342.15 ) = 0.246 mol of Al_2(SO4)_3So in an 84.2g sample of Al_2(SO4)_3 (aka aluminum sulfate), there are 0.246 moles. This is correct because in one mole of Al_2(SO4)_3, there are 342.15g and the sample of 84.2 g of Al_2(SO4)_3 is way smaller than that, so our answer should be less than one mole, which it is.
I hope this helped!
A cook grabs the handle of the frying pan and their hand gets very warm. The cook's hand gets very warm because of?
a. conduction
b.radiation
c.convetion
When Robert Hooke looked at cork through a microscope , he named what he saw “cells” because__________
a. He could barely see what he was looking at
b. The cork looked like shells
c. They were the holes of the cork
d. The cork looked like tiny rectangular rooms
Answer:
D. The cork looked like tiny rectangular rooms
Explanation:
The invention that helped scientists discover the cell is the microscope. Tell why Hooke called the structures he saw in the cork cellular("small rooms"). He called them cellular because the box like cells reminded him of the monks monasteries.
After two half-lives, how much of the original material has decayed? 25 percent 50 percent 75 percent 100 percent
The original material has decayed 75%
Further explanationGiven
two half-life
Required
The decayed sample
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
t = 2 x t 1/2
Input the value :
[tex]\tt \dfrac{Nt}{No}=\dfrac{1}{2}^2=\dfrac{1}{4}=25\%[/tex]
The amount of Nt = 25% No
Antonio and Addie want to know if perfume fumes affect plant height. They place five identical bean plants in five identical light boxes. In four of the boxes, they place 200 milliliters (mL) of perfume at different distances from the plants, and they make observations twice a week for one month. Which choice best identifies the observation data that should be included in their data table?
Answer:
leaf colors and root lengths
Explanation:
law of conservation of energy
A
B
C
D
What percent of the products that result from chlorination of isopentane (2-methylbutane) would have following structure?
6.) The bond between which two atoms is most polar?*
1)C-O
2)OFF
3)он-0
4)Ο N-Η
Answer:
O-H bond
Explanation:
Let us work out the electronegativity difference between the elements in each bond in order to decide which of them is most polar.
For the C-O bond
2.55 - 2.2 =0.35
For the F-F bond
3.98 - 3.98 = 0
For the O-H bond
3.44 - 2.2 = 1.24
For the N-H bond
3.04 - 2.2 = 0.84
The O-H bond has the highest electronegativity difference, hence it is he most polar bond.
Why is petrified wood considered a fossil?
Petrified wood was part of a plant that has been changed into rocks.
Petrified wood is can be burned to make create energy.
Petrified wood is dense like a fossil.
Petrified wood contains minerals that are only found in fossils.
Answer:
Petrified wood contains minerals that are only found in fossils.
Explanation:
learned it in school (promise)
What would the volume of a gas be at -125°C, if it had a volume of 693 mL at 45°? A -1,925 mL b. 322.5 mL c. 2,279 mL d. 15.4 mL
Answer: b. 322.5 mL
Explanation:assume constant pressure, then
693/(273.15+45) = v/(273.15-125)
v= 693*148.15/318.15 = 322.7
By using Charles law, the volume will be 322.5 mL
What is Charle's law?
The volume of such an ideal gas is proportional to its absolute temperature at constant pressure, according to Charles' law.
According to Charles law.
[tex]T_{1} / T_{2} = V_{1} / V_{2}[/tex]
where, T is temperature and V is volume.
What is volume?A substance or object's volume refers to the amount of 3D space it takes up.
Calculation of volume.
Given data:
V = 693 mL
[tex]T_{1}[/tex] =-125°C = (273-125) = 148 K
[tex]T_{2}[/tex] = 45° = (273+45) = 318 K
Put the value of given data in Charles law formula.
148 K/ 318 K = V / 693 mL
V = 322.5 mL.
Therefore, by using Charles law the volume of a gas will be 322.5 mL.
To know more about Charles law.
https://brainly.com/question/16927784
#SPJ2
A sample consisting of 65.0 g of xenon is confined in a container at 2.00 atm and 298 K and then allowed to expand adiabatically (a) reversibly to 1.00 atm, (b) against a constant pressure of 1.00 atm. Calculate the final temperature and the expansion work at each case. Use the fact that xenon is a monoatomic gas.
Answer:
[a]. - 445.45J,
[b]. - 367.92 J
Explanation:
The following parameters are given in the question above. These information are used in solving this problem.
The mass of Xenon = 65.0 g of xenon, pressure = 2.00 atm, temperature = 298 K.
The number of moles of xenon = mass/ molar mass = 65g/ 131.293= 0.495.
The cp= 3/2 R, cp =3/2R + R = 5/2 R.
j = cp/cv = 3/2.
[a]. The final temperature,T2 = (2)^-2/3 × (298)^5/3 = T2^5/3.
Final temperature,T2 = 225.84K.
Expansion work = nCv [ T₂ - T₁] = 0.495 × 3/2 × 8.314 × [ 225.84 - 298] = - 445.45J.
(b). The final temperature can be Determine as;
3/2( T2 - 298k) = - 1 (T2 /1 - 298/2).
3/2(T2 - 298) = - T2 + 149K.
3T2 - 894 = - 2T2 +298K.
T2 = 238.4 K.
Workdone= nCv (T2 - T1) = 0.495 × 3/2 × 8.314 (238.4 - 298) = - 367.92 J.
1.5 pts) The Rf value of compound A is 0.29 when developed in petroleum either and 0.44 when developed in dichloromethane. Compound B has an Rf value of 0.45 in petroleum either and 0.69 in dichloromethane. Which solvent would be better for separating a mixture of compounds A and B. Briefly explain your choice. What is petroleum ether
Answer:
The better solvent for separating the mixture of A and B is dichloromethane
Explanation:
Petroleum ether is the mixture of hydrocarbons obtained from the petroleum distillation with a boiling range between 35 and 60°C. Is used as a solvent.
In the other hand, the best solvent for separating a mixture in TLC is the one that has the higher difference between RF's of the compounds.
The difference in RF's in dichloromethane is:
|0.44 - 0.69| = 0.25
In petroleum ether:
|0.29 - 0.45| = 0.16
That means the better solvent for separating the mixture of A and B is dichloromethane
A hypothetical element X is found to have an atomic mass of 37.45 amu. Element X has only two isotopes, X-37 and X-38. The X-37 isotope has a fractional abundance of 0.7721 and an isotopic mass of 37.24. What is the isotopic mass of the other isotope?
Answer: The isotopic mass of the other isotope is 38.16 amu
Explanation:
Mass of isotope X-37 = 37.24
fractional abundance of isotope X-37 = 0.7721
Mass of isotope X-38 = ?
fractional abundance of isotope X-38 = (1-0.7721)= 0.2279
Formula used for average atomic mass of an element :
[tex]\text{ Average atomic mass of an element}=\sum(\text{atomic mass of an isotopes}\times {{\text { fractional abundance}})[/tex]
[tex]37.45=\sum[(37.24\times 0.7721)+(x\times 0.2279)][/tex]
[tex]x=38.16[/tex]
Therefore, the isotopic mass of the other isotope is 38.16 amu
One mole of a metallic oxide reacts with one mole of hydrogen to produce two moles of the pure metal
and one mole of water. 5.00 g of the metallic oxide produces 2.32 g of the metal. What is the metallic
oxide? (Use molar masses)
Answer:
Lithium oxide, Li₂O.
Explanation:
Hello!
In this case, according to the given amounts, it is possible to write down the chemical reaction as shown below:
[tex]M_2O+H_2\rightarrow 2M+H_2O[/tex]
Which means that the metallic oxide has the following formula: M₂O. Next, we can set up the following proportional factors according to the chemical reaction:
Thus, we perform the operations in order to obtain:
[tex]\frac{10X}{(2X+16)}=2.32[/tex]
So we solve for x as shown below:
[tex]10X=2.32(2X+16)\\\\10X=4.64X+37.12\\\\X=\frac{37.12}{10-4.64}\\\\X= 6.93g/mol[/tex]
Whose molar mass corresponds to lithium, and therefore, the metallic oxide is lithium oxide, Li₂O.
Best regards!
A 980 pound horse is diagnosed with strongyle parasites. The veterinarian orders he be given 10 milligrams per kilogram of de-wormer. How many milligrams will he need?
Aluminum reacts with iron nitrate to form aluminum nitrate and iron. What is the
reactant, or what are the reactants, in this chemical equation?
aluminum nitrate
aluminum nitrate and iron
iron and aluminum
aluminum and iron nitrate
Which of the following metals (M) will form an ionic compound with nitrogen with the general formula M3N2?
Answer:
There are no options provided dude,
But i guess the answer will be a metal with valency 2 for sure as the subscript given for N in 'M3N2' is 2 so the valency of the metal u need to select will be 2 for sure
It can be magnesium or some other if the provided options in real question has Mg then its the answer
09. Where does Mitosis take place? I
where growth and repair are happening
in your hair cells only
in your blood cells only
Answer:
In plants mitosis takes place throughout life in growing regions called the meristems. Replacements as cells wear out. The cells of the skin and bone marrow are sites of active mitosis replacing skin cells and red blood cells that only have a limited life. Repair.
Explanation:
Help plz :( Convert 48,000 seconds into hours. (Two step problem, use two conversion factors in a row)
Answer:
13.3 h
Explanation:
Step 1: Given data
Time (t): 48,000 seconds
Step 2: Convert "t" from seconds to minutes
We will use the conversion factor 1 min = 60 s.
48,000 s × 1 min/60 s = 800 min
Step 3: Convert "t" from minutes to hours
We will use the conversion factor 1 h = 60 min.
800 min × 1 h/60 min = 13.3 h
To sum up, 48,000 seconds is equal to 13.3 hours.
How many molecules in 4.10 mol H2O?
6.02×10^23
1.4×10^23
2.47×10^24
1.15×10^-23
Answer:
2,47 * [tex]10^{24}[/tex] (molecules)
Explanation:
Avogadro's number is a very important relationship: 1 mole = 6,02 * [tex]10^{23}[/tex] atoms, molecules, protons, etc.
To convert from moles to molecules, multiply the molar amount by Avogadro's number.
4,1 mol * 6,02 * [tex]10^{23}[/tex] ≈ 24,7 * [tex]10^{23}[/tex] = 2,47 * [tex]10^{24}[/tex] (molecules)
Therefore the third answer is correct
Consider an experimental setup with two compartments separated by a phospholipid bilayer membrane containing ion channels selectively permeable only to chloride ions. The left compartment (also called inside) contains 1 mM Cl- and the right compartment (also called outside) contains 100 mM Cl-. What will the electrical potential be when the system attains equilibrium
This question is incomplete, the complete question is;
Consider an experimental setup with two compartments separated by a phospholipid bilayer membrane containing ion channels selectively permeable only to chloride ions. The left compartment (also called inside) contains 1 mM Cl- and the right compartment (also called outside) contains 100 mM Cl-. What will the electrical potential be when the system attains equilibrium? [ assume body temperature; log 100 = 2, log 10 = 1, log 1 = 0, log 0.1 = -1, log 0.01 = -2]
Options;
a) -62 mV
b) -124 mV
c) +62 mV
d) 0 mV
e) +124 mV
Answer:
the electrical potential be when the system attains equilibrium is –124mV
Option b) –124mV is the correct answer
Explanation:
Given the data in the question;
Two compartments are divided by lipid bilayer;
In inside compartment Cl- ion concentration- 1mM and out side of the cell concentration is 100mM
now we apply the Nernst equilibrium potential equation;
Chlorine ion valency is z = –1
So
[tex]E_{eq}[/tex] = 62/z × log(ion outside/ ion inside) [for Cl‐ ions]
[tex]E_{eq}[/tex] = (62 / –1) x log( 100 / 1 )
[tex]E_{eq}[/tex] = -62 x 2 =
[tex]E_{eq}[/tex] = –124mV
Therefore, the electrical potential be when the system attains equilibrium is –124mV
Option b) –124mV is the correct answer
Which bond will each pair of elements form?
Explanation: Sodium is a metal with a low electronegativity it will form an ionic bond with a non metal with a high electronegativity.
Both Florine and Sulfur are non metals with high electronegativity.
Neon is a noble gas family VIII A and normally doesn't form any bonds at all.
MARK ME BRAINLIST
19. Which wind water interaction is responsible for cycling nutrient-rich waters
from the ocean floor to the sea surface?
A. upwelling
B.storm surge
C.downwelling
D.surface currents
Explanation:
ksiiaisisjjsjajajhahajajjalañLzlzl
Explanation: A . upwelling .
Question 101 pts The ideal gas law tends to become inaccurate when Group of answer choices the pressure is raised and the temperature is lowered. the pressure is lowered and molecular interactions become significant. the temperature is raised above the temperature of STP. large gas samples are involved. the volume expands beyond the standard molar volume.
Answer:
the pressure is raised and the temperature is lowered
Explanation:
According to the ideal gas law, there is no interaction between the molecules of an ideal gas. This implies that the molecules of an ideal gas are largely separated from each other and move around at great velocities in the vessel.
However, when the pressure is raised, molecules come into closer proximity with each other, similarly, when the temperature is lowered, the average kinetic energy of gas molecules is also lowered and intermolecular interaction become significant under these conditions. Hence, the ideal gas law now become inaccurate.
One mole of a metallic oxide reacts with one mole of hydrogen to produce two moles of the pure metal
and one mole of water. 5.00 g of the metallic oxide produces 2.32 g of the metal. What is the metallic
oxide? (Use molar masses)
Answer:
Lithium oxide, Li₂O.
Explanation:
Hello!
In this case, according to the given amounts, it is possible to write down the chemical reaction as shown below:
[tex]M_2O+H_2\rightarrow 2M+H_2O[/tex]
Which means that the metallic oxide has the following formula: M₂O. Next, we can set up the following proportional factors according to the chemical reaction:
Thus, we perform the operations in order to obtain:
[tex]\frac{10X}{(2X+16)}=2.32[/tex]
So we solve for x as shown below:
[tex]10X=2.32(2X+16)\\\\10X=4.64X+37.12\\\\X=\frac{37.12}{10-4.64}\\\\X= 6.93g/mol[/tex]
Whose molar mass corresponds to lithium, and therefore, the metallic oxide is lithium oxide, Li₂O.
Best regards!
Can someone help me please ??
Answer:
11. C
12. A
13. C
14. A
Explanation:
1.
How many miles per hour is 30.5 m/s?
Answer:
68.22656
Explanation:
I think this is the answer.
Hope it's correct!
Answer:
68.22656
Explanation:
Speed
30.500001382
Meter per second
=
68.22656
Miles per hour
Formula
multiply the speed value by 2.237
(hope this helps can i plz have brainlist :D hehe)
A 25 liter balloon holding 1.5 moles of carbon dioxide leaks. If we are able to determine that 0.9 moles of carbon dioxide escaped before the container could be sealed, what is the new volume of the container?
Answer:
10 Litre
Explanation:
Given that ::
v1 = 25L ; n1 = 1.5 mole ; v2 =? ; n2 = (1.5-0.9) = 0.6 mole
Using the relation :
(n2 * v1) / n1 = (n2 * v2) / n2
v2 = (n2 * v1) / n1
v2 = (0.6 mole * 25 Litre) / 1.5 mole
v2 = 15 / 1.5 litre
v2 = 10 Litre
convert
chloroethane
into enene
God Has Given wing To Birds
Answer:
and birds can fly without wings es hora de vomer