Answer:
C. The use of coal
Explanation:
Answer:
C. The use of coal
Explanation:
Edge 2021
Each iron atom has a mass of about 9 x 1023 grams. Even a small grain of iron has an incredible number of atoms in. it--about 1 x 1018 atoms in one grain. Which of these is most similar to the number of atoms in a grain of iron?
Answer:
A) The number of atoms in a grain of iron is most similar to the number of meters between Earth and Vega.
The options attached to the question are missing, but out of the numbers presented in the options, 10¹⁷ is closest to 10¹⁸.
B) The mass of a grain of iron is approximately (9 × 10⁻⁵) g
Explanation:
The options attached to the question are missing, after searching online, the image of the question was obtained, but it won't be attached to this solution in order not to violate the community guidelines and lead to deletion of answer.
But, out of the numbers presented in the options, 10¹⁷ is closest to 10¹⁸, hence, the number of atoms in a grain of iron is most similar to the number of meters between Earth and Vega.
The second part of the question asks for the approximate mass of a grain of iron.
1 atom of iron has a mass of (9 × 10⁻²³) g
1 grain of iron has about (1 × 10¹⁸) atoms of iron.
So, the mass of a grain of iron = (9 × 10⁻²³) × (1 × 10¹⁸) = (9 × 10⁻⁵) g
Hope this Helps!!!
a. Which date shows a waning crescent?
Answer:
Warning means that it is getting smaller while crescent refers to the crurved shape simular to a banana or a boat. The warning crescent moon rises after midnight and is still up and visible in the morning and day sky before itsets in the afternoon.
Explanation:
What is the identity of the element whose isotopes you have selected
Answer:
Rubidium
Explanation:
Nil
The identity of the element whose isotopes you have selected is that it significantly possesses the same atomic number but a different mass number.
What is Isotope?The Isotope may be characterized as one of two or more types of atoms of a chemical element that significantly have the same number of protons but with different numbers of neutrons and therefore different atomic masses.
In a more simple sense, an isotope may be defined as an atom that has the same atomic number but different atomic mass and physical properties.
It is the identity of the element that they togetherly possess the same number of protons which leads to identical atomic numbers but due to a distinct number of neutrons, they possess different mass numbers.
Therefore, the identity of the element whose isotopes you have selected is that it significantly possesses the same atomic number but a different mass number.
To learn more about Isotopes, refer to the link:
https://brainly.com/question/160068
#SPJ2
Which of these was not proposed by john dalton in 1805?
A. All matter is made of atoms.
B. Adams are made of protons, neutrons and electrons.
C. During chemical reactions, atoms rearrange themselves.
D. The atoms of a particular element are all identical.
Answer:
Atoms are made of protons, neutrons and electrons.
Explanation:
The Dalton's atomic theory was an early attempt at describing the properties of atoms. It stipulated that atoms were the smallest indivisible particle of a substance. Chemical reactions occur as a result of a combination or separation of atoms. Atoms of the same element are exactly alike and differ from atoms of other elements. Atoms can neither be created nor destroyed.
As time went on, modern scientific evidence began to modify the original postulates of the Dalton's atomic theory. It was not postulated in 1805 that atoms were composed of subatomic particles; electrons, neutrons and protons. Dalton's theory held the atom to be 'indivisible'. However in 1897, JJ Thompson discovered the electron. Subsequently, the proton and neutrons were discovered. This shows that the atom in itself consisted of even smaller particles.
consider the balanced chemical equation below. when the chemical reaction was carried out calculated theoretical was yield for sodium bromide 162 grams but the measured yield was 150 grams what is the percent yield?
Answer:
Explanation:
% yield = (actual yield / theoretical yield) X 100
For this question,
% yield = (150g/ 162 g) X 100 = 92.6%
Answer:
92.6%
Explanation:
A sample of sugar (C12H22O11) contains
1.505 × 1023 molecules of sugar. How many moles of sugar are present in the sample? Answer without doing any calculations.
0.25 mol
0.50 mol
1.00 mol
2.50 mol
Answer:
0.25 mol
Explanation:
Use the formula n=N/NA
n= number of mols
N = number of particles
Nᵃ = Avogadros constant = 6.02 x [tex]\\10^{23[/tex]
So, n= [tex]\frac{1.505 X 10^{23} }{6.02 X 10^{23}}[/tex]
The 10 to the power of 23 cancels out and you are left with 1.505/6.02, which is approximately 1/4. This is the same as 0.25 mol.
Hope this helped :)
An empty container weighs 80.21 g. it is filled with 20.14 mL of an unknown liquid, and the total weight of the container and liquid is 105.22 g. What is the density of the liquid?
Answer:
1.242 g/mL
Explanation:
Step 1: Given data
Mass of the empty container (m₁): 80.21 g
Mass of the filled container (m₂): 105.22 g
Volume of the unknown liquid (V): 20.14 mL
Step 2: Calculate the mass of the liquid
The mass of the liquid is equal to the difference between the mass of the filled container and the mass of the empty container.
[tex]m = m_2 - m_1 = 105.22g - 80.21 g = 25.01 g[/tex]
Step 3: Calculate the density of the unknown liquid
The density of the liquid is equal to its mass divided by its volume.
[tex]\rho = \frac{m}{V} = \frac{25.01g}{20.14mL} = 1.242 g/mL[/tex]
What is the oxidation state of nitrogen in N2?
O A. +5
O B.-3
O C. +3
O D.O
Answer:
D) 0 (zero)
Explanation:
There's a rule that neutral compounds (compound) without charges have oxidation of zero. Also, another formula that if two atoms of the same element make one single molecules such as diatomics molecules are O2, N2, I2, Br2 oxidation states are zero, thus here N is 0 (Zero) as well.
Which step is this ?prophase I, Anaphase I, prophase II, Anaphase II
Answer:
Prophase 1
Explanation:
Answer:
The correct answer will be prophase I
Explanation:
During this stage, the genetic code is together and hasn't split yet therefore, the answer is prophase I hopefully this helps!
What is the molarity of a solution when 3.58 moles of NaCl are dissolved in 2.12 L of solution?
Answer:
1.69 M
Explanation:
Molarity is the ratio of moles to liters:
(3.58 moles)/(2.12 liters) = 1.6887 moles/liter ≈ 1.69 M
In a neutralization reaction with a strong acid or base, all of the hydrogens from the acid and the hydroxides from the base react to form water.
Balance the following neutralization reaction:
H3PO4 (aq) + NaOH (aq) â H2O (l) + Na3PO4 (aq)
Enter the appropriate coefficient to the left of the respective term. In the event that your coefficient would be "1" be sure to write "1" as opposed to leaving it blank.
Answer:
H3PO4 + 3NaOH ----> Na3PO4 + 3H2O
Explanation:
The balanced equation is given below
H3PO4 + 3NaOH ----> Na3PO4 + 3H2O
Answer:
[tex]H_3PO_4 (aq) + 3NaOH (aq) \rightarrow 3H_2O (l) + Na_3PO_4 (aq)[/tex]
Explanation:
Hello,
In this case, for the given reaction:
[tex]H_3PO_4 (aq) + NaOH (aq) \rightarrow H_2O (l) + Na_3PO_4 (aq)[/tex]
We must assure the law of conservation of mass is respected, so we equal the number of atoms at each side of the equation by adding the stoichiometric coefficients to the left of each compound as shown below:
[tex]H_3PO_4 (aq) + 3NaOH (aq) \rightarrow 3H_2O (l) + Na_3PO_4 (aq)[/tex]
So the coefficients are 1, 3, 3 and 1 respectively for each species in the chemical reaction.
Regards.
What disease is spread through warm climates ?
Answer:
malaria
Explanation:
PLEASE HELP BEFORE 7 A.M. PACIFIC TIME
SEE ATTACHED.
Answer:
(i) 32.9 mL; (ii) 37.5 mL; (iii) 21.73 mL
Explanation:
You should always try to read a measuring instrument to a tenth of the smallest scale division.
Here, you are measuring liquids, so you take the scale reading from the bottom of the meniscus.
(i) Graduated cylinder
There are 10 divisions between 30 mL and 40 mL, so each division represents 1 mL.
The level of the liquid appears to be between 32 mL and 33 mL. It is much closer to 33 mL (perhaps right on 33 mL).
You should report the volume to the nearest 0.1 mL. I would read the volume as 32.9 mL, but 32.8 and 33.0 are also acceptable.
Note: If you think the level is right on the 33 mark, you report the volume as 33.0 mL (NOT 33 mL).
(ii) Thermometer
The reading is about half-way between 87 ° and 88 °.
I would report the temperature as 87.5 °, but 87.4 ° and 87.6 ° would also be acceptable.
(iii) Buret
There are 10 divisions between 21 mL and 22 mL, so each division represents 0.1 mL.
You should estimate to the nearest 0.01 mL.
The liquid level is about a third of the way from 21.7 mL to 21.8 mL.
I would report the volume as 21.73 mL, but 21.72 mL and 21.74 mL are also acceptable.
In the news recently, an individual poured an unknown liquid substance over a female victim and fled on
foot. The victim sustained chemical burns to her face, neck, shoulder, and back (source: NYPD). What
could the unknown substance have been?
water
a base, only
either an acid or a base
an acid, only
Answer:
either an acid or a base
Explanation:
Especially, concentrated acids and bases tend to do enormous amounts of chemical burns. People usually think its only acids but the strongest of bases can easily melt our skin.
Watch the video to determine which of the following relationships are correct according to Boyle’s law.
1. PV∝P
2. P∝V
3. PV∝V
4. P∝1V
5. V∝1P
6. V∝P
Part B. Standard temperature and pressure (STP) are considered to be 273 K and 1.0 atm. Predict which of the following changes will cause the volume of the balloon to increase or decrease assuming that the temperature and the gas filling the balloon remain unchanged. Drag the appropriate items to their respective bins.
A. Volume increases
B. Volume decreases
C. Volume is unchanged
Part C. If a certain gas occupies a volume of 20 L when the applied pressure is 10 atm, find the pressure when the gas occupies a volume of 5.0 L. Express your answer to two significant figures, and include the appropriate units.
ki, kf =
Part D. If a certain gas occupies a volume of 18 L when the applied pressure is 9.0 atm , find the pressure when the gas occupies a volume of 4.5 L .Express your answer to two significant figures and include the appropriate units.
Answer:
Part A
Boyle's Law is given mathematically as
P ∝(1/V) or V ∝(1/P)
Options 4 and 5, if they are properly written.
Part B
At constant temperature, and according to the Boyle's law for an ideal gas,
A. What can cause a Volume increase is a corresponding decrease in pressure.
B. What can cause a Volume decrease is a corresponding increase in pressure.
C. The Volume is unchanged if the pressure of the gas is unchanged too.
Part C
The pressure when the gas occupies a volume of 5.0 L = 40 atm
Part D
The pressure when the gas occupies a volume of 4.5 L = 36 atm
Explanation:
Part A
Boyle's Law states that at constant temperature, the pressure of an ideal gas is inversely proportional to the volume occupied by the gas.
So, mathematically, Boyle's Law is given as
P ∝(1/V) or V ∝(1/P)
Part B
Inverse relationship between two quantities means that the higher the value of one of the quantities go, the lower the value of the other quantity goes and vice versa.
So, at constant temperature, and according to the Boyle's law for an ideal gas.
A. What can cause a Volume increase is a corresponding decrease in pressure.
B. What can cause a Volume decrease is a corresponding increase in pressure.
C. The Volume is unchanged if the pressure of the gas is unchanged too.
Part C
A certain gas occupies a volume of 20 L when the applied pressure is 10 atm, find the pressure when the gas occupies a volume of 5.0 L.
According to Boyle's Law for an ideal gas,
P ∝(1/V)
P = (k/V)
where k is the constant of proportionality
PV = k
Therefore,
P₁V₁ = P₂V₂ = k
P₁ = 10 atm
V₁ = 20 L
P₂ = ?
V₂ = 5.0 L
10 × 20 = P₂ × 5
P₂ = 40 atm
Part D
If a certain gas occupies a volume of 18 L when the applied pressure is 9.0 atm , find the pressure when the gas occupies a volume of 4.5 L
P₁V₁ = P₂V₂ = k
P₁ = 9.0 atm
V₁ = 18 L
P₂ = ?
V₂ = 4.5 L
9 × 18 = P₂ × 4.5
P₂ = 36 atm
Hope this Helps!!!
A compass needle normally points toward Earth’s magnetic pole, which is near the North Pole. Which best explains why the needle moves away from the pole when it comes close to a current-carrying wire? -Current within the wire weakens the magnetic force of the pole. -Magnetism surrounding the wire weakens the magnetic force of the pole. -Magnetism surrounding the wire draws the needle toward the wire.
Answer:
Magnetism surrounding the wire draws the needle toward the wire.
Explanation:
Magnetism is a force which is responsible for the attraction and repulsion of objects. Magnetism is also generated around the wire in which current is flowing. This magnetism is stronger when more current flows through the wire. This magnetism is stronger than the magnetism of the poles so when the compass brought near to the electric wire, the needle moves toward the wire.
Answer:
D. -Magnetism surrounding the wire draws the needle toward the wire.
Explanation:
A chemistry graduate student is studying the rate of this reaction:
NH4OH(aq)→NH3(aq)+H2O(aq)
She fills a reaction vessel with and measures its concentration as the reaction
proceeds: time (seconds).
1. Write the rate law for this reaction.
2. Calculate the value of the rate constant.
Answer:
See explaination
Explanation:
Please kindly check attachment for the step by step solution of the given problem
With 21 g of Zinc, and 7 g of CuCl2, how much ZnCl2 is made in grams?
Answer: 7.07 grams
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}\times{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} zinc=\frac{21g}{65g/mol}=0.32moles[/tex]
[tex]\text{Moles of} CuCl_2=\frac{7g}{134g/mol}=0.052moles[/tex]
[tex]Zn+CuCl_2\rightarrow Cu+ZnCl_2[/tex]
According to stoichiometry :
1 mole of [tex]CuCl_2[/tex] require 1 mole of [tex]Zn[/tex]
Thus 0.052 moles of [tex]CuCl_2[/tex] will require=[tex]\frac{1}{1}\times 0.052=0.052moles[/tex] of [tex]Zn[/tex]
Thus [tex]CuCl_2[/tex] is the limiting reagent as it limits the formation of product and [tex]Zn[/tex] is the excess reagent.
As 1 mole of [tex]CuCl_2[/tex] give = 1 mole of [tex]ZnCl_2[/tex]
Thus 0.052 moles of [tex]CuCl_2[/tex] give =[tex]\frac{1}{1}\times 0.052=0.052moles[/tex] of [tex]ZnCl_2[/tex]
Mass of [tex]ZnCl_2=moles\times {\text {Molar mass}}=0.052moles\times 136g/mol=7.07g[/tex]
Thus 7.07 g of [tex]ZnCl_2[/tex] will be produced from the given masses of both reactants.
A Na2CO3 standard solution is prepared by transferring 2.4817 g of primary
standard-grade sodium carbonate (fw = 106 g/mol) to a 250-ml volumetric flask.
Dissolving the sample in - 100 mL distilled water and diluted to the mark. A 25.0
mL aliquot is taken and titrated with 42.65 mL of HCl, calculate the
concentration of the HCl solution?
Answer:
0.1098 M
Explanation:
Calculate the value deltaG°
Answer:
ΔG=ΔG0+RTlnQ where Q is the ratio of concentrations (or activities) of the products divided by the reactants. Under standard conditions Q=1 and ΔG=ΔG0 . Under equilibrium conditions, Q=K and ΔG=0 so ΔG0=−RTlnK . Then calculate the ΔH and ΔS for the reaction and the rest of the procedure is unchanged.
Explanation:
An aqueous solution contains 0.30 M potassium fluoride.
One liter of this solution could be converted into a buffer by the addition of:_______.
(Assume that the volume remains constant as each substance is added.)
A. 0.15 mol NaOH
B. 0.30 mol HNO3
C. 0.29 mol HF
D. 0.29 mol KBr
E. 0.15 mol HNO3
Answer:
A. 0.15 M NaOH, and
E. 0.15 M HNO3
Explanation:
A buffer solution contains a conjugate acid-base pair with both the acid and the base in reasonable concentrations.
NaOH and HNO3 is an acid base pair with relatively equal concentrations. So, they would most likely make a buffer solution.
which compound is an electrolyte ? 1) butene 2) propane
Answer:
1.)
Explanation:
Hydrogen gas at a temperature of 22.0°C that is confined in a 5.00L cylinder exerts a pressure of 4.20atm. If the gas is released into a 10.0L reaction vessel at a temperature of 33.6°C, what will be the pressure inside the reaction vessel?
Answer:
THE NEW PRESSURE WHEN THE GAS IS RELEASED INTO A 10 L REACTION VESSEL AND AT 33.6 °C TEMPERATURE IS 2.18 atm.
Explanation:
The general gas equation will be used to calculate the new pressure.
P1V1 /T1 = P2 V2 / T2
P1 = 4.20 atm
V1 = 5 L = 5 dm3
T1 = 22°C = 22 + 273 K = 295 K
V2 = 10 L = 10 dm3
T2 = 33.6 °C = 33.6 + 273 K = 306.6 K
P2 =?
Rearranging the formula and making P2 the subject of the equation, we have;
P2 = P1V1 T2 / T1 V2
P2 = 4.2 * 5 * 306.6 / 295 * 10
P2 = 6438.6 / 2950
P2 = 2.18 atm.
So therefore, the pressure inside the reaction vessel when the gas is released into a 10 L reaction vessel and at a temperature of 33.6 °C is 2.18 atm.
Answer:
The pressure inside the reaction vessel is 2.18 atm
Explanation:
Step 1: Data given
The temperature = 22.0 °C = 295.15 K
Pressure = 4.20 atm
Volume = 5.0 L
Volume increased to 10.0 L
Temperature increased to 33.6 °C = 306.75K
Step 2: Calculate the new pressure
P1 * V1 / T1 = P2*V2 / T2
⇒with P1 = the initial pressure = 4.20 atm
⇒with V1 = the initial volume = 5.0 L
⇒with T1 = the initial temperature = 295.15 K
⇒with P2 = the new pressure = TO BE DETERMINED
⇒with V2 = the increased volume = 10.0L
⇒with T2 = the increased temperature = 306.75 K
(4.20 atm * 5.0 L) / 295.15 K = ( P2 * 10.0 L ) / 306.75 K
P2 = (4.20 * 5.0 L * 306.75 K) / (295.15 K * 10.0 L)
P2 = 2.18 atm
The pressure inside the reaction vessel is 2.18 atm
Answers only please 100pts and brainliest. you will be reported for wrong answers.
Answer:
1. 42.75 grams KOH
2. Add 150ml of water to the 250ml containing 9.8 grams 42.75 grams KOH
Explanation
1. moles KOH in 500ml in 1.5M solution = 0.500L x 1.5 mole/Liter = 0.75 mol KOH
grams KOH in 0.75 mole = 0.75 mole x 57 grams/mole = 42.75 grams KOH
2. formula weight H₃PO₄ = 98 grams/mole
9.8 grams H₃PO₄ in 250ml H₂O => 9.8g/98g·mole⁻¹/0.250Liters = 0.40M in H₃PO₄
Final volume of 0.25M H₃PO₄ solution = (0.40M)(250ml)/(0.25M) = 400ml
∴ Add 400ml - 250ml = 150ml of water to the 250ml of 0.40M H₃PO₄ solution => 400ml of 0.25M H₃PO₄ solution.
Answer:
1. 42.75 grams koh
2. add 150 ml of water to the 250 ml containing 9.8 grams 42.75 grams koh
Explanation:
Which kind of bond occurs when two atoms share an electron
Answer:
Covalent bondExplanation:
pH and pOH Formulas
Concentration Formulas
pH = -log[H30)
[H30*) = 10-PH
pOH = -log(OH)
[OH] = 10-POH
pH + POH = 14.00
[H3O+][0] = 1.0 10-14
What is the hydronium (H30*) concentration of a solution with a pH of 3.60?
A 2.5 x 10^M
B 3.0 x 10-M
C 4.0 x 10M
D.
45* 10-11M
Answer:
A. 2.5 x 10^M
Explanation:
H+=10^-pH
- Hope that helps! Please let me know if you need further explanation.
Answer:
A. 2.5 x 10^M
Explanation:
i took the test and i got it correct (edmentum)
1. Chromium metal is reacted with 40.0mL of 3.0M tin (IV) chloride in the following reaction:
4Cr + 3SnCl4 --> 4CrCl3 + 3Sn
How many grams of tin will be produced? (3 marks) Please upload your work.
(Non-anonymous question )
Answer:
14.2 g
Explanation:
40.00 mL = 0.04000 L solution of SnCl4
3.0 M = 3.0 mol/L Molarity of solution of SnCl4
3.0 mol/L * 0.04000 L = 0.12 mol SnCl4
4Cr + 3SnCl4 --> 4CrCl3 + 3Sn
from reaction 3 mol 3 mol
given 0.12 mol x mol
x = 0.12 mol Sn
Molar mass (Sn) =118.71 g/mol
0.12 mol Sn * 118.71 g/mol≈ 14.2 g
A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is a stainless-steel cylinder that measures wide and high. The maximum safe pressure inside the vessel has been measured to be .
For a certain reaction the vessel may contain up to of carbon monoxide gas. Calculate the maximum safe operating temperature the engineer should recommend for this reaction. Write your answer in degrees Celsius. Be sure your answer has the correct number of significant digits.
Answer:
T = 643K = 643-273.15 = 369.85°C = 370°C = maximum safe operating temperature
Explanation:
The actual question has following data which the question given has missing
The vessel is a stainless-steel cylinder that measures wide 25.0 cm and 30.0 cm high.
The maximum safe pressure inside the vessel is 6.60 MPa.
The vessel may contain up to 0.800 kg of carbon monoxide gas.
Volume of cylinder = pi x r^2 x h = 3.14 x (25/2)cm^2 x 30cm = 14725.78 cm^3 or 0.01472578 m^3
Now, using ideal gas law, PV = nRT
P = 6.60×10^6 Pa
V = 0.01472578 m^3
n= no. of moles = mas staken/ molar mass of CO2 = 800g/44g/mol = 18.18
moles
R = 8.314 J/mol.K
So, (6.60x10^6 ) x 0.01472578 = 18.18×8.314×T
T = 643 K = 643-273.15 = 369.85°C = 370°C = maximum safe operating temperature
Types of radioactive decay
How do you think rocks form?
Answer:
Through gradual accumulation of sediments
Explanation: