Answer:
the main use of coal in the United States is to generate electricity.
Coal is a combustible black or brownish-black sedimentary rock with a high amount of carbon and hydrocarbons
Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.
A geologist is attempting to date a layer of sedimentary rock. He performs radioactive dating using uranium-235, which has a half-life of 703 million years. He determines that the uranium-235 has undergone 3 half-lives. Approximately how old is the rock?
710 billion years
2.11 billion years
710 million years
235 million years
2.11 million years
none of the above
Answer:
2.11 billion years.
Explanation:
I hope this helps! Have a great rest of your day!
Please help me with 1,2,3,4,5,6
Answer:
1a 2b 3c 4d 5c 6c that is the answer to your quesrion i believe
A student collects 25 mL of gas at 0.98 bar. What volume would this gas occupy at 1.013 bar? * 3 points 25.8 mL 24.2 mL .09 mL 34.7 mL
Answer:
24.2 mL.
Explanation:
Assuming constant temperature, we can solve this problem using Boyle's law, which states:
P₁V₁=P₂V₂Where:
P₁ = 0.98 barV₁ = 25 mLP₂ = 1.013 barV₂ = ?We input the data:
0.98 bar * 25 mL = 1.013 bar * V₂And solve for V₂:
V₂ = 24.18 mLThe closest option is the second one: 24.2 mL.
Please help me with this homework
What coefficients would balance the following equation?
__Al + __O2 → __Al2O3
A. 2Al + 3O2 → 1Al2O3
B. 2Al + 3O2 → 2Al2O3
C. 3Al + 3O2 → 2Al2O3
D. 4Al + 3O2 → 2Al2O3
A Pitot-static probe is used to measure the speed of an aircraft flying at 3000 m. If the differential pressure reading is 3100 N/m2, determine the speed of the aircraft in m/s. The density of air at an altitude of 3000 m is 0.909 kg/m3. The speed of the aircraft is km/h.
Answer:
82.59 m/s or 297.324 km/h
Explanation:
From the question,
Applying
V = √[2(P'/ρ)].................. Equation 1 ( From
Where V = Speed of the aircraft, Differential Pressure of the air craft, ρ = Density of air at an altitude of 3000 m.
Given: P' = 3100 N/m², ρ = 0.909 kg/m³
Substitute into equation 1
V = √[2(3100/0.909)]
V = √(2×3410.34)
V = √(6820.68)
V = 82.59 m/s
V = 297.324 km/h
Hence the speed of the aircraft is 82.59 m/s or 297.324 km/h
If an atom of Phosphorous has 17 neutrons, what is its mass number?
a) 31
b) 32
c) 15
D) 17
which is BEST used to describe a chemical reaction that also produces a change in heat?
a. exothermic reaction
b. chemical reaction
c. thermochemical reaction
d. nuclear reaction
will give brainliest
Answer:
I think it's thermochemical reaction and sorry if it's wrong
Pls help me I don’t know what to dooooo
Fractional distilation of liquid air usually produces nitrogen and oxygen as major products . Substance used to remove carbon iv oxide from air before its changed to liquid
Answer:
Caustic soda
Explanation:
The fractional distillation of air is carried out on liquid air. Before air is liquified, the carbon dioxide content of air is removed using caustic soda. The air is then compressed to a pressure of about 200 atm, sudden expansion of the gas leads to cooling. The process continues until air becomes liquid at -200°C.
Fractional distillation of liquid air usually produces nitrogen and oxygen as major products. nitrogen in obtained first since it has a lower boiling point than oxygen. The gases are then dried, compressed and stored in cylinders.
How many grams of H2O would be made from 7.9 moles of H2? (Round to one decimal place)
Answer:
2.01588 grams
Explanation:
structure of periodic table explain
Explanation:
Elements are arranged from left to right and top to bottom in order of increasing atomic number. ... The number of electrons in a period increases as one moves down the periodic table; therefore, as the energy level of the atom increases, the number of energy sub-levels per energy level increases.
which deflects winds to the right or left
a) jet streams
b) land breeze
c) sea breeze
d) coriolis effect
Answer: right and what are the answers for?
Explanation:
What is the molarity of a solution in which 175.8
grams of NaCl is dissolved in 1.5 L of water?
water is at 0 degrees celsius if we continue to remove energy from the water what phase changes would occur
Answer:
Solid/freezing
Explanation:
Solid has the least energy of all of the phase changes and the more energy is lost the colder its gets then water turns into a solid called ice hope i helped!
if you push the head of a nail against your skin and then push the point of the same nail against your skin with the same force the point of the nail may pierce your skin while the head of the nail will not why is that
Answer:
Sure I'll help you!
Explanation:
The head of the nail is flat and isn't sharp enough to cut anything, If you stab someone with a sword then hit them with a shield would it have the same effect? Of course not.
Se valoró una alícuota de 10ml de HCl con NaOH AL 0.0548M de la cual se gastó 17.9ml. La concentración molar del ácido es:
Answer:
se lonh hion ffyuk jlngvn
Balance the following chemical equation by providing the correct coefficients:
[ ]N2 + [ ]H2 -> [ ]NH3
Nitrogen + hydrogen produces ammonia (NH3)
Answer:
1 N2 + 3 H2 --> 2 NH3 :))) !!
1) A 45.7 g sample of glass was brought to thermal equilibrium with boiling water and then transferred to 250.0 g of water that was at 22.5 °C. This combination reached thermal equilibrium at 24.2 °C. What is the specific heat capacity of glass?
2) What mass of silver at 100.0 °C, when added to 150.0 g of water at 21.0 °C, would raise the water’s temperature to 24.0 °C ?
3) The molar heat of fusion of H2O is 6.1 kJ/mole. What amount of energy would be needed to melt 376 g of ice at 0.0 °C?
1) A 45.7 g sample of glass was brought to thermal equilibrium with boiling water and then transferred to 250.0 g of water that was at 22.5 °C. This combination reached thermal equilibrium at 24.2 °C. What is the specific heat capacity of glass?
2) What mass of silver at 100.0 °C, when added to 150.0 g of water at 21.0 °C, would raise the water’s temperature to 24.0 °C ?
3) The molar heat of fusion of H2O is 6.1 kJ/mole. What amount of energy would be needed to melt 376 g of ice at 0.0 °C?
pb(No3)2(aq) +2KCI(aq)---PbCl2(s)+KNO2(aq). how many grams of PbCl2 solution will react with a 0.46 L of a 0.101m KCI solution
Answer:
6.3986g
Explanation:
The balanced chemical equation of this reaction is as follows:
Pb(NO3)2(aq) + 2KCl (aq) → PbCl2(s) + 2KNO3(aq)
In this equation, 2 moles of KCl solution will produce 1 mole of PbCl2.
To calculate the number of moles of PbCl2 produced, we use the formula:
Molarity = number of moles (n) ÷ volume (V)
0.101 = n/0.46
n = 0.046mol of KCl
If 2 moles of KCl solution will produce 1 mole of PbCl2
Then, 0.046mol of KCl will be react to produce (0.046 × 1/2) of PbCl2
0.046 × 1/2 = 0.023mol of PbCl2
To find the mass of PbCl2 using mole = mass ÷ molar mass
Molar mass of PbCl2 = 207.2 + 35.5(2)
= 207.2 + 71
= 278.2g/mol
0.023 = mass/278.2
mass = 6.3986g
Answer:
Can you help me with other question please
The measured amount of product obtained from a chemical reaction
is the.
An unknown compound in the lab is either LiOH, CaF2, or LiF. If the sample has a mass of 260 grams and contains 3.33 moles, what is the identity of the compound?
Answer:
CaF2
Explanation:
1 mole of CaF2 = 78.0748064 grams
78 times 3.33= 259.74
the others multiplied were nowhere near 260 grams either
According to the Law of Conservation of Energy, energy ______.
Is a mixture with the same composition throughout
Answer:
A homogeneous mixture
Explanation:
A homogeneous mixture has the same composition throughout
Explain how the cardiovascular system helps your body function
Answer:
The blood circulatory system (cardiovascular system) delivers nutrients and oxygen to all cells in the body. It consists of the heart and the blood vessels running through the entire body. The arteries carry blood away from the heart; the veins carry it back to the heart.
Explanation:
You're welcome!
Stay Safe!
Write the expressions for the equilibrium constants of the reactions below.
a. N2 + 3H2 ⇌ 2NH3
b. Br2 + H2 ⇌ 2HBr
c. CO + H2O ⇌ H2 + CO2
In general, for a given chemical reaction in equilibrium
[tex]aA + bB \rightleftharpoons cC + dD[/tex]
the equilibrium constant, Keq, will be
[tex]K_{eq}=\frac{\mathrm{[C]^c}[D]^d}{\mathrm{[A]^a[B]^b}}.[/tex]
Usually, only aqueous and gaseous species are included in the equilibrium constant; the concentration of any pure solid or liquid is omitted. While the states of the reactants and products in the reactions for this problem aren't given, these three particular reactions all happen to be ones where they can (and, in fact, do) occur where all the species are in the gaseous state. So, all the reactants and product(s) are included in the equilibrium constants below, but this will not always be the case.
a.
[tex]K_{eq}=\frac{\mathrm{[NH_3]^2}}{\mathrm{[N_2][H_2]^3}}[/tex]
b.
[tex]K_{eq}=\frac{\mathrm{[HBr]^2}}{\mathrm{[Br][H_2]}}[/tex]
c.
[tex]K_{eq}=\frac{\mathrm{[H_2][CO_2}]}{\mathrm{[CO][H_2O]}}[/tex]
The equilibrium constant has to do with the value that shows the extent to which reactants are converted into products.
What is equilibrium constant?The term equilibrium constant has to do with the value that shows the extent to which reactants are converted into products.
The following are the expressions for the equillibrium constant of each reaction;
[tex]K = [NH3]^2/[N2] [H2]^3[/tex][tex]K = [HBr]^2/[Br2] [H2][/tex][tex]K= [H2] [CO2]/[CO] [H2O][/tex]Learn more about equilibrium constant:https://brainly.com/question/10038290
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The driver of an 1,840 kg race car applies the brake to come to a complete stop. If the car
accelerates at -3.4 m/s2 what is the net force acting on the race car?
a) -541 N
b) 630 N
c) -1.8 N
d) -6,256 N
Push and pull subjected to an object is called force and is given in newtons. The net force acting on the race car is -6,256 N.
What is force?Force is the product of the mass of the object in kg and the acceleration in meters per second square. It is given by the formula:
[tex]\rm F = m \times a[/tex]
Given,
Mass of the race car = 1,840 kg
Acceleration of the race car = -3.4
Substituting values in the above equation:
[tex]\begin{aligned} \rm F &= \rm m \times a \\\\&= 1840 \times -3.4\\\\&= -6,256 \;\rm N \end{aligned}[/tex]
Therefore, option D. -6,256 N is the force acting on the car.
Learn more about force here:
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The density of a gas was found to be 19.1 g/L at 2.25 atm and 19.3°C. What is the molar mass of
the gas?
Answer:
Explanation:
Recall that the density of a gas is its mass to volume ratio,
ρ
=
m
V
. Therefore, if we can determine the mass of some volume of a gas, we will get its density. The density of an unknown gas can used to determine its molar mass and thereby assist in its identification. The ideal gas law, PV = nRT, provides us with a means of deriving such a mathematical formula to relate the density of a gas to its volume
The element cobalt displays many similarities to the element iron and is also attracted to magnets. Based on this information, is it likely that cobalt forms magnetic domains? Explain your answer.
In ferromagnetic materials, smaller groups of atoms band together into areas called domains, in which all the electrons have the same magnetic orientation. That's why you can magnetize them.
What is the meaning of magnetic domains?A portion of a ferromagnetic material where the magnetic moments are aligned with one another because of interactions between molecules or atoms.
In ferromagnetic materials, the atoms form structures called domains.
A domain is a region inside of a material where groups of magnetic moments naturally align in the same direction.
There can be numerous domains within an object.
Learn more about magnetic domains here:
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What is the specific heat of a 22.8 g sample of metal that absorbs 1,450 Joules of heat from 21.8 degrees Celsius to 75.0 degrees Celsius?
Answer: The specific heat of given metal is [tex]1.195 J/^{o}C[/tex].
Explanation:
Given: Mass of sample = 22.8 g
Heat energy = 1450 J
Initial temperature = [tex]21.8^{o}C[/tex]
Final temperature = [tex]75^{o}C[/tex]
Formula used to calculate the specific heat is as follows.
[tex]q = m \times C \times (T_{2} - T_{1})[/tex]
where,
q = heat energy
m = mass of substance or sample
C = specific heat
[tex]T_{1}[/tex] = initial temperature
[tex]T_{2}[/tex] = final temperature
Substitute the values into above formula as follows.
[tex]q = m \times C \times (T_{2} - T_{1})\\1450 J = 22.8 g \times C \times (75 - 21.8)^{o}C\\C = \frac{1450 J}{22.8 \times 53.2^{o}C}\\= 1.195 J/^{o}C[/tex]
Thus, we can conclude that the specific heat of given metal is [tex]1.195 J/^{o}C[/tex].