Answer:
He discovered the electron- J.J Thompson
He discovered periodic changes in properties of elements when they are listed in order of their atomic weights- Dimitri Mendeleev
He experimented with the deflection of cathode rays by a magnetic field- J.J Thompson
He carried out experiments, using gold foil, that measured the scattering of positively charged alpha particles by heavy atoms- Ernest Rutherford
He proposed that atoms are the basic units of matter- John Dalton
He proposed the model of the atom had most of its mass concentrated in a very small nucleus- Ernest Rutherford
He proposed that in a chemical reaction, atoms are neither created nor destroyed-John Dalton
Explanation:
J.J Thompson was the discoverer of the electrons. He also worked hard to show that they were negatively charged particles after he experimented with them using a magnetic field. He named them cathode rays.
Dimitri Mendeleev found that, when all the known chemical elements were arranged in order of increasing atomic weight, the resulting table displayed a recurring pattern, or periodicity, of properties within groups of elements(Encyclopedia Britannica).
Ernest Rutherford demonstrated by experiment using a thin gold foil and alpha particles that the atoms are composed of a positive massive core called the nucleus.
John Dalton proposed that matter is composed of atoms. Also, in a chemical reaction, atoms are neither created nor destroyed.
WHAT IS A PLACE WHERE BOOKS ARE CLASSIFIED! I NEED HELP!
Answer:
From the Online Catalog to the Shelf
Libraries in the United States generally use either the Library of Congress Classification System (LC) or the Dewey Decimal Classification System to organize their books. Most academic libraries use LC, and most public libraries and K-12 school libraries use Dewey.
Explanation:
Answer:
From the Online Catalog to the Shelf
Libraries in the United States generally use either the Library of Congress Classification System (LC) or the Dewey Decimal Classification System to organize their books. Most academic libraries use LC, and most public libraries and K-12 school libraries use Dewey.
You are working with a concentrated solution of ammonium hydroxide which place of safety equipment is most important to have on hand
The mass spectrum of compound A shows the molecular ion at m/z 85, an M +1 peak at m/z 86 of approximately 6% abundance relative to M, and an M+2 peak at m/z 87 of less than 0.1% abundance relative to M. Assuming that compound A has only C, H, and one N atoms, determine the molecular formula, and then draw a possible structure if compound A has IR absorption at 1620-1680 cm^-1 but not at 3010-3090 cm^-1 .
Answer:
(1). CH3-CH=N-CH2-CH2-CH3.
(2). CH3-CH2-CH =N-CH2-CH3.
(3). CH3-CH2-CH2-CH=N-CH3.
(3). CH3-CH2-CH2-CH2-CH=N.
Explanation:
This is a spectroscopy question. Spectroscopy is an important part of chemistry which is used in the identification of chemical compounds.
So, without mincing words let's dive straight into the solution to the question.
Starting from values of IR given, the absorption at 1620-1680 cm^-1 shows the presence of C = N.
From the question, it is given that there is no signal showing on the spectrum at 3010 - 3090 cm^-1. The absorption at 3010 - 3090 cm^-1 shows the presence of N - H. But, it is not show on the spectrum. Hence, there is no N - H in the compound. That's, there are no Hydrogen atoms attached to Nitrogen atom.
We are given that the mass spectrum of compound A shows the molecular ion at m/z 85, therefore the molar mass of the compound is 85.
Also, from the question the elements present are carbon, Hydrogen and Nitrogen. Therefore, the compound is likely to be C5H11N.
The likely compounds are given below;
(1). CH3-CH=N-CH2-CH2-CH3.
(2). CH3-CH2-CH =N-CH2-CH3.
(3). CH3-CH2-CH2-CH=N-CH3.
(3). CH3-CH2-CH2-CH2-CH=N.
the pH of a solution prepared by the addition of 100mL 0.002M HCL to 100mL distilled water is closest to:
a.1.0
b.1.5
c.2.0
d.3.0
Answer:
d.3.0
Explanation:
Step 1: Calculate the final volume of the solution
The final volume is equal to the sum of the volumes of the initial HCl solution and the volume of distilled water.
V₂ = 100 mL + 100 mL = 200 mL
Step 2: Calculate the final concentration of HCl
We will use the dilution rule.
C₁ × V₁ = C₂ × V₂
C₂ = C₁ × V₁/V₂ = 0.002 M × 100 mL/200 mL = 0.001 M
Step 3: Calculate the pH of the final HCl solution
Since HCl is a strong acid, [H⁺] = HCl. We will use the definition of pH.
pH = -log [H⁺] = -log 0.001 = 3
How many moles of a gas would be held by a 6 L container of nitrogen gas at 2 atm and 300 Kelvin?
Answer:
I think you would have to multiply 6 times 2, which it equals 12. And then just divide it by 300, and that's your answer. Hope I was able to help!
Explanation: Have a good day!
Which weather event usually occurs when a cold front moves into an area?
O A. mild weather, because cold air pushes warmer air to the side
O
B. mild weather, because cold air pushes warmer air up
C. a storm, because cold air pushes warmer air up
O D. a storm, because cold air pushes warmer air to the side
What's the pollen tube also known as
Answer:
The stigma.
Explanation:
You're welcome. :)
A container of water and an equal-sized container of oil are heated at the same rate. After several minutes, the temperature of the oil has risen 20 degrees C, but the temperature of the water has only increases by 8 degrees C. What explains this?
Question 6 options:
Heat moves from the water to the oil.
It takes more energy to increase the temperature of water than to increase the temperature of oil
The water contains more atoms, so it has more thermal energy
More heat was added to the oil than to the water.
Answer: It takes more energy to increase the temperature of water than to increase the temperature of oil.
Explanation:
yes
Draw the bridged bromonium ion that is formed as an intermediate during the bromination of this alkene. Include hydrogen atoms, nonbonding electrons, and formal charge(s) in your structure. The starting alkene is a 4 carbon chain with a double bond between carbons 2 and 3. The substituents on the alkene are on opposite sides of the alkene. This reacts with B r 2 to give the intermediate ion.
Answer:
See explanation and image attached
Explanation:
The reaction of bromine molecule with an alkene passes through a bridged intermediate known as the brominium ion.
It is a cyclic intermediate that contains a positively charged bromine ion as i have shown in the image attached.
The brominium ion is first formed during the bromininaton of alkenes.
what are the characteristics of elastic energy
The bonds between the atoms of an item or substance store elastic energy. When these bonds are under stress, they absorb energy and release it when they are relaxed.
What is elastic energy ?Elastic energy is the mechanical potential energy held in a material's or a physical system's configuration while it is subjected to elastic deformation as a result of work being done on it.
Elastic energy is created when things are momentarily crushed, stretched, or otherwise distorted. Calculations of mechanical equilibrium locations using the elastic potential energy equation.
The energy is potential because when the item is permitted to return to its original shape by its elasticity, it will change into other types of energy, such as kinetic energy and sound energy.
Thus, The bonds between the atoms of an item or substance store elastic energy.
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Aqueous hydrochloric acid will react with solid sodium hydroxide to produce aqueous sodium chloride and liquid water . Suppose 14. g of hydrochloric acid is mixed with 6.55 g of sodium hydroxide. Calculate the minimum mass of hydrochloric acid that could be left over by the chemical reaction. Round your answer to significant digits.
Answer:
8.02 g of HCl could be left over by the chemical reaction
Explanation:
We propose the reaction:
HCl(aq) + NaOH (s) → NaCl (aq) + H₂O (l)
Ratio is 1:1. First of all, we determine the moles of reactants:
14 g . 1mol / 36.45g = 0.384 mol of acid
6.55 g. 1mol / 40g = 0.164 mol of base
If a determined mass of HCl, could be left; this means that the acid is the excess reagent.
For 0.164 moles of NaOH, we need 0.164 moles of HCl.
As we have 0.384 moles, (0.384 - 0.164) = 0.220 moles of acid are left over in the reaction. We convert the moles to mass:
0.220 mol . 36.45 g /1mol = 8.02 g
I have tried the answer 3.9149 and 3.914, it is incorrect
Answer:
Yea pretty much it's 3.49
Explanation:
Given that a 0.130 M HCl(aq) solution costs $39.95 for 500 mL, and that KCl costs $10/ton, which analysis procedure is more cost-effective
Answer:
KCl is cost effective
Explanation:
In order to know this, we need to see how much it cost 1 g of each reactant. Let's begin with HCl
HCl:
In this case, let's calculate the moles of HCl in a 0.130 M solution and then, the mass of HCl using the molecular weight of 36.5 g/mol, to get the cost the HCl at the end using the given price:
nHCl = 0.130 moles/L * 0.5 L = 0.065 moles
mHCl = 0.065 moles * 36.5 g/mol = 2.3725 g
Cost HCl = 39.95 $ / 2.3725 g = 16.84 $/g
Conclusion, 1 g of HCl costs 16.84 $
KCl:
In this case, it's pretty obvious that 1 ton of KCl cost 10$, so, there is no need to do further calculations because 1 ton (or more than 1000 kg of the salt) it's just 10$. This is less expensive than the 16.84$ for just 1 g of HCl, so, final conclusion, KCl is more cost-effective.
Hope this helps
three molecules of oxygen react with four molecules of hydrogen to produce water molecules write a balanced chemical equation
Answer:
ExpC
H
4
+
2
O
2
→
C
O
2
+
2
H
2
O
This is the balanced reaction equation for the combustion of methane.
Explanation:
The Law of Conservation of Mass basically states that matter can neither be created nor destroyed. As such, we must be able to show this in our chemical reaction equations.
If you look at the equation above, you'll see an arrow that separates the reaction equation into two parts. This represents the direction of the reaction.
To the left of the arrow, we have our reactants.
To the right of the arrow, we have our products.
The quantity of each individual element in the left must equal the quantity of each individual element in the right.
So if you look below, you'll see the unbalanced equation, and I'll try to explain how to balance the reaction.
C
H
4
+
O
2
→
C
O
2
+
H
2
O
Our reactants in this equation are
C
H
4
and
O
2
.
Our next step is to break these down into individual atoms.
We have:
1 C atom, 4 H atoms & 2 O atoms.
If you're confused by this, look to see the little number to the bottom right of each element, the subscript, and it tells you how many of each atom are in the molecule. Make sense?
Now we look to the other side of the equation.
Here we see our products are
C
O
2
+
H
2
O
Again, we break these down into individual atoms again.
We have:
1 C atom, 2 H atom, 3 O atom
Convert 65.4 m to mm.
Helppp please
Answer:65.4 meters= 65400 millimeters
magnesium and copper react with dilute acids to make salts and hydrogen gas
True
False
Answer:
True
Explanation:
magnesium and copper react with dilute acids to make salts and hydrogen gas
Why is it important to keep detailed records and notes about evidence and the crime scene
Answer:
It is important to record the crime scene in order to view how it was originally found so when items are removed, it can still be investigated and viewed.
Explanation:
A certain reaction with an activation energy of 185 kJ/mol was run at 505 K and again at 525 K . What is the ratio of f at the higher temperature to f at the lower temperature
Answer:
The ratio of f at the higher temperature to f at the lower temperature is 5.356
Explanation:
Given;
activation energy, Ea = 185 kJ/mol = 185,000 J/mol
final temperature, T₂ = 525 K
initial temperature, T₁ = 505 k
Apply Arrhenius equation;
[tex]Log(\frac{f_2}{f_1} ) = \frac{E_a}{2.303 \times R} [\frac{1}{T_1} -\frac{1}{T_2} ][/tex]
Where;
[tex]\frac{f_2}{f_1}[/tex] is the ratio of f at the higher temperature to f at the lower temperature
R is gas constant = 8.314 J/mole.K
[tex]Log(\frac{f_2}{f_1} ) = \frac{E_a}{2.303 \times R} [\frac{1}{T_1} -\frac{1}{T_2} ]\\\\Log(\frac{f_2}{f_1} ) = \frac{185,000}{2.303 \times 8.314} [\frac{1}{505} -\frac{1}{525} ]\\\\Log(\frac{f_2}{f_1} ) = 0.7289\\\\\frac{f_2}{f_1} = 10^{0.7289}\\\\\frac{f_2}{f_1} = 5.356[/tex]
Therefore, the ratio of f at the higher temperature to f at the lower temperature is 5.356
Define these terms: (a) unimolecular reaction (b) bimolecular reaction (c) elementary reaction (d) overall reaction
Answer:
See explanation
Explanation:
A unimolecular reaction is an elementary reaction in which the rearrangement of a single molecule produces one or more molecules of product(Chem Purdue).
A bimolecular reaction refers to the chemical combination of two molecular entities in a reaction that can be considered either reversible or irreversible(Springer).
Elementary reaction refers to any reaction that takes place in a single reactive encounter.
Overall reaction is the sum of all the steps of a non-elementary reaction.
Soda pop is carbonated with CO2. Mark puts one bottle of soda pop in the refrigerator and leaves the other out in the hot sunlight. After one hour, he opens both bottles. Which bottle will likely have more fizzing and bubbles? Why?
Answer:
The one left in the hot sunlight.
Explanation:
The solubility of gases decreases when temperature increases. The gas in the soda pop (CO2) left in the sun will not stay dissolved as much as the on left in the refrigerator.
Soda is a carbonated drink with soda or water and a sweetener. Soda pop in the fridge will have more fizzing and bubbles.
What is carbonated?Carbonated drinks are drinks or beverages that contain dissolved carbon dioxide. They have small bubbles and fizz of the carbon dioxide present in them.
Carbonation of the drinks is linked to the temperature as at high temperature, liquid tends to lose the carbon dioxide fizz. The carbon dioxide bubbles are retained at low temperatures as the solubility of the carbon dioxide is increased.
Therefore, the bottle kept in the refrigerator will have more bubbles and fizz.
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Silver oxide a compound, an element, homogeneous mixture or heterogeneous mixture
Answer:
Element
Explanation:
Answer:
Silver oxide is a chemical compound
Explanation:
Silver oxide is the chemical compound with the formula Ag2O.
What is the total pressure in atmosphere (atm) of a gas mixture containing argon gas at 0.28 atm, helium gas at 760 mm Hg, and nitrogen gas at 760 torr?
Answer:
I dont know, sorry!
Question 3 (5 points)
Potassium chlorate decomposes into potassium chloride and oxygen gas according to
the following equation:
2 KCIO3 --> 2 KCl + 3 02
Use the equation above to answer the questions that follow:
How many grams of oxygen will be produced from the decomposition of 425 g of
potassium chlorate?
Do not put the answer in scientific notation. Do not include the substance as part of
your unit. Units should be all lowercase letters and singular (not plural) and no
spaces among units. You will choose from the following units:
Answer:
332.918g O2
Explanation:
I'm having some issues with the work however, your final answer should be 332.918g O2
Hope this helped!
What are the missing coefficients for the skeleton equation below? Cr(s) + Fe(NO3)2(aq) → Fe(s) + Cr(NO3)3(aq)
Answer:
2 3 3 2
Explanation:
which metals take part in chemical reactions when exposed to the air?
Answer:
sodium metal take part when exposed to air
The most important commercial ore of chromium is chromite (FeCr2O4). One of the steps in the process used to extract chromium from the ore is the reaction of chromite with coke (carbon) to produce ferrochrome (FeCr2). 2 C(s) FeCr2O4(s) FeCr2(s) 2 CO2(g) What mole ratio would you use to convert from moles of chromite to moles of ferrochrome
Answer:
1 mole FeCr2/ 1 mole FeCr2O4
Explanation:
We have to write down the equation of the reaction before we can answer the question;
2C(s) + FeCr2O4(s) -------> FeCr2(s) + 2CO2(g)
By inspection of this reaction equation, we can clearly see that the mole ratio of the reactants and products is 2:1:1:2.
Specifically, the ratio of chromites to ferrochrome is 1:1
Hence;
The mole ration required to convert chromites to ferrochrome is;
1 mole FeCr2/ 1 mole FeCr2O4
What is the balanced equation of:
2Mg+ H2So4
Answer: CH3COO)2Mg + H2SO4 = MgSO4 + CH3COOH
Explanation:
Hope. This helps
A sample of 7.34 g of solid calcium hydroxide is added to 34.5 mL of 0.380 M Aqueous hydrochloric acid.Write the balanced chemical equation for the reaction. Physical states are optional.
Answer: [tex]Ca(OH)_2(s)+2HCl(aq)\rightarrow CaCl_2(aq)+2H_2O(l)[/tex]
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced chemical equation is:
[tex]Ca(OH)_2(s)+2HCl(aq)\rightarrow CaCl_2(aq)+2H_2O(l)[/tex]
Some hypothetical alloy is composed of 25 wt% of metal A and 75 wt% of metal B. If the densities of metals A and B are 6.17 and 8.00 g/cm3 , respectively, and their respective atomic weights are 171.3 and 162.0 g/mol, determine whether the crystal structure for this alloy is simple cubic, facecentered cubic, or body-centered cubic. Assume a unit cell edge length of 0.332 nm
Answer:
Simple cubic
Explanation:
The density of metal A (ρa) = 6.17 g/cm³, The density of metal B (ρb) = 8 g/cm³, The atomic weight of metal A (Aa) = 171.3 g/mol, The atomic weight of metal B (Ab) = 162 g/mol, the unit cell edge length (a) = 0.332 nm, concentration of metal A (Ca) = 25%, concentration of metal B (Cb) = 75%
The average density is given by:
[tex]\rho_{ave}=\frac{100}{\frac{C_a}{\rho_a} +\frac{C_b}{\rho_b} } \\\\\rho_{ave}=\frac{100}{\frac{25}{6.17} +\frac{75}{8} } =7.45\ g/cm^3\\\\The\ average\ atomic\ weight\ is:\\\\A_{ave}=\frac{100}{\frac{C_a}{A_a} +\frac{C_b}{A_b} } \\\\A_{ave}=\frac{100}{\frac{25}{171.3} +\frac{75}{162} } =164.23\ g/mol\\\\The\ number\ of\ atoms\ per\ unit(n)\ is:\\\\n=\frac{\rho_{ave}*a^3*N_A}{A_{ave}} \\\\N_A=Avogadro\ constant=6.02*10^{22} \ mol^{-1},a=0.332\ nm=3.32*10^{-8}cm\\\\Substituting:\\\\[/tex]
[tex]n=\frac{\rho_{ave}*a^3*N_A}{A_{ave}} =\frac{7.45*(3.32*10^{-8})^3*6.02*10^{23}}{164.23} \\\\n=0.999\\[/tex]
n≅1
Since n≅1, the crystal structure for this alloy is simple cubic
Abu Ali al-Hasa invented the words____and___
A.hypothesis, theory
B.scientific, theory
C.science, hypothesis
D.solution, science
Abu Ali al-Hasa invented the words hypothesis and theory. option A is correct.
What is hypothesis and theory?The hypothesis is a concept in which the experiment is to be performed for which the research is going to be done and the conclusion or the results of that experiment tell about the some things from which scientists make some hypothesis which are not confirmed information.
The theory of any experiment is about the conformation of that particular research by which the further studies is to be held for further researches these two words given by Abu Ali al-Hasa.
Therefore, Abu Ali al-Hasa invented the words hypothesis and theory. option A is correct.
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