Answer:
The postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
Explanation:
The law of constant composition (or definite proportion) states that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
This law implies that irrespective of the source of the sample of the compound or the method by which the sample was prepared, as long as the sample is pure, the elements present in the compound are always combined in a specific ratio by mass. For example, water has the molecular formula H₂O. Irrespective of the water source, for example, tap-water, lake, stream, river or rainfall, each pure sample of water will have the constant composition of 2 atoms of hydrogen to one atom of oxygen.
The given compound exists as XO in nature. Therefore, irrespective of the source or method of preparation, every sample of this compound should have the formula XO. Since the compound prepared by the scientist was XO₂, therefore, the postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass was violated by the scientist. The scientist must have prepared a different compound of the elemental compositions.
Calculate the percentage composition of Aluminum, Sulfur & Oxygen in the compound of Al(SO4)3
Answer:
Percentage of O = 56.1 %
Percentage of Al =15.8%
Percentage of S = 28.1 %
Explanation:
Given compound Al₂(SO₄)₃
Molar mass of compound:
27×2 + 32×3 + 16×12 = 342 g/mol
Percentage of Al = ( Mass of Al / Total mass ) × 100
Percentage of Al = 54 /342 × 100
Percentage of Al =15.8%
Percentage of S = ( Mass of S / Total mass ) × 100
Percentage of S = 96 /342 × 100
Percentage of S = 28.1 %
Percentage of O = ( Mass of O / Total mass ) × 100
Percentage of O = 192 /342 × 100
Percentage of O = 56.1 %
There are 2 grams of sulfur and 0.45 grams of copper. What is the
percent composition of coppper in the sample.
A. 18.3 %
B. 5.44 %
C. 81.6 %
D. 1.25%
Answer:
18.3%
Explanation:
Add the numbers together, and then take the number of grams of the substance, in this case copper, not coppper lol. divide the .45 by 2.45 to get 18.3
Covalent bonds can be single, double, or triple.
How many electrons are shared in a molecule, like O2 that has a double bond?
4
6
12
2
This chemical equation represents a chemical reaction H2SO4 + 2LiOH Li2SO4 + 2H2O which two chemicals are the products of the chemical reaction shown?
Answer:
Lithium sulphate (Li₂SO₄) and water (H₂O
Explanation:
H₂SO₄ + 2LiOH —> Li₂SO₄ + 2H₂O
The equation represented above indicates a neutralization reaction.
A neutralization reaction is a reaction involving acid and base which result in the production of salt and water.
In the equation above,
Reactant:
H₂SO₄ (acid)
LiOH (base)
Product:
Li₂SO₄ (salt)
H₂O (water)
Thus, lithium sulphate (Li₂SO₄) and water (H₂O) are the products of the reaction
In _____ , materials move from an area of higher concentration to an area of lower concentration through a cell membrane.
1.selective permeability
2.active transport
3.passive transport
a sample of methane gas at a pressure of 0.727 atm and a temperature of 26.9 occupies a volume of 726 ml. if the gas is allowed to expand at constant temperature until its pressure is 0.412 atm, the volume of the gas sample will be _ mL
Answer:
1280L
Explanation:
Given parameters:
Initial pressure = 0.727atm
Temperature = 26.9°C
Initial volume = 726mL = 0.726L
New pressure = 0.412atm
Unknown:
New volume of the gas sample = ?
Solution:
To solve this problem, we apply boyles law;
P1V1 = P2V2
P and V are pressure and temperature
1 and 2 are initial and new state
0.727 x 0.726 = 0.412 x V2
V2 = 1.28mL = 1280L
Write the name for the IONIC compound that contains two aluminum atoms and three sulfur atoms. (Need help ASAP)
. The kidneys are _______________ to the liver.
a. Dorsal
b. Ventral
c. Medial
d. Superior
If the [H+] of a solution is 6.8 x 10-9 mol/L the pH is
Answer:
8.2
Explanation:
To solve this problem;
The concentration of [H⁺] = 6.8 x 10⁻⁹mol/L
So, we need to convert this to pH:
pH = -log [H⁺]
So;
pH = -log 6.8 x 10⁻⁹ = 8.2
Can someone answer ASAP if you hurry I will mark brainliest
Answer:
Electrical and magnetic
You exert a gravitational force on the pupil and the pupil exerts an equal gravitational force on you. ... The size of the gravitational force depends on the mass of the objects involved. The greater the mass, the greater the gravitational force.
Explanation:
Plss answer the question in the picture.
How many different methods can you list for how we generate electricity in this country. Which of those methods do we use the most, and which of them should we invest more in
Answer:
1. Broadly, there are three different methods for how electricity is generated in the United States. They include; Fossil fuels, Nuclear energy, and Renewable energy sources.
2. Fossil fuels, are used the most, with Natural gas topping the list by 38%.
3. More should be invested into renewable gas. It is a clean source of energy and investing in it would bring about a cleaner and safer environment.
Explanation:
Fossil fuels arise from plants and animals that have been long dead and can can now be converted to sources of energy. Examples include; coal natural gas, crude oil. etc.
Nuclear energy arises from the fission of uranium atoms, nuclear decay, and nuclear fusion. They are safe since green house gases are not emitted. Thermal energy can be generated as the byproduct of these reactions.
Renewable sources of energy are generated from natural sources which are always available. Examples are; sun, wind, biomass, water, and geothermal sources,
Calculate the molar mass of NaNO3-
AYOO SMART PEOPLE I NEED HELP on number 6
Answer:
6.) mixture
8.) compound
Something that causes a response in an organism is called a(n) _____.
An atom of chlorine with a mass number of 37 contains __ protons and __ neutrons.
Answer:
Its in the Explanation
Explanation:
Here's what I got.
Aluminium-27 is an isotope of aluminium characterized by the fact that is has a mass number equal to
27
.
Now, an atom's mass number tells you the total number of protons and of neutrons that atom has in its nucleus. Since you're dealing with an isotope of aluminum, it follows that this atom must have the exact same number of protons in its nucleus.
The number of protons an atom has in its nucleus is given by the atomic number. A quick looks in the periodic table will show that aluminum has an atomic number equal to
13
.
This means that any atom that is an isotope of aluminum will have
13
protons in its nucleus.
Since you're dealing with a neutral atom, the number of electrons that surround the nucleus must be equal to the number of protons found in the nucleus.
Therefore, the aluminium-27 isotope will have
13
electrons surrounding its nucleus.
Finally, use the known mass number to determine how many neutrons you have
mass number
=
no. of protons
+
no. of neutrons
no. of neutrons = 27 − 13 = 14
Your welcome :)
What is the role of the nervous system?
Answer:
Explanation:
The major regulation, regulatory, and communicating system in the body is the nervous system. It is the foundation of all mental operation, including thinking, learning, and memory. The nervous system, along with the endocrine system, is responsible for controlling and sustaining homeostasis.
Which is a property of potassium (K)?
A. It is dull and brittle.
B. It is extremely reactive.
C. It is not reactive.
D. It is white and hard.
Answer:
B: It is extremely reactive
Explanation:
Potassium metal is also soft and white with a silvery lustre, has a low melting point, and is a good conductor of heat and electricity.
Answer: Properties, occurrence, and uses. Potassium metal is soft and white with a silvery lustre, has a low melting point, and is a good conductor of heat and electricity. Potassium imparts a lavender colour to a flame, and its vapour is green.
Explanation: hope it helps
Consider the reaction below.
2 Na + O2 → Na2O2
If 10.0 g of sodium metal reacts with excess oxygen gas how many grams of sodium oxide will be produced?
Show your work below. Make sure to show ALL units and each step of the process:
Answer:
I think 5
Explanation:
What is it that lives if it is fed, and dies if you give it a drink
Answer:
fire
Explanation:
Answer:
ants if you splash a ant with sum water that shít is dead
is reacts with acid a chemical or physical property? (WORTH 30 Points.)
Answer:
Metals in general have they chemical property of reacting with an acid. Zinc reacts with hydrochloric acid to produce hydrogen gas. This is a chemical property. Chemical change results in one or more substances of entirely different composition from the original substances.
Metal reacts with acid is a chemical property.
Metals react with acids which causes the production of salt and hydrogen gas is released. This is a chemical property because the reactions of reactant produces new type of products which is totally change from the parent material or reactants. The chemical property is refers to change of one type of matter into another type so we can conclude that reaction of metals with acid is a chemical property.
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Did Adam Jackson win by
Answer:
by a number
Explanation:
Answer:
Hm may you edit the question and put in the full question all it says is "Did Adam Jackson win by"
Explanation:
.
What is the product(s) of the reaction below?
2Al(s) + Fe2O3(s) ---> Al2O3(s) + 2Fe(s)
A. Solid aluminum oxide and solid iron
B. Solid aluminum
C. Saturated aluminum oxide and saturated iron
D. Iron(III) oxide and aluminum oxide
Answer:
A. Solid aluminum oxide and solid iron
Explanation:
The reaction equation is given as:
2Al + Fe₂O₃ → Al₂O₃ + 2Fe
The species on the left hand side are the reactants
Those on the right hand side of the expression are the products.
The products are:
Al₂O₃ and Fe
These are solid aluminum oxide and solid iron
___co+__ Na2s--> ___ Na+ ___ cos2
Answer: [tex]Co+2Na_2S\rightarrow 4Na+CoS_2[/tex]
Explanation:
According to law of conservation of mass, mass can neither be created nor be destroyed. The atoms on the reactant side must be equal to the number of atoms on the product side so that the mass remains the same on reactant and product side. Thus the reactions are balanced.
Single displacement reaction is one where a more reactive element replaces the lesser reactive one.
The balanced chemical reaction will be:
[tex]Co+2Na_2S\rightarrow 4Na+CoS_2[/tex]
Suppose that 3.33 g of acetone at 25.0 °C condenses on the surface of a 44.0-g block of aluminum that is initially at 25 °C. If the heat released during condensation goes only toward heating the metal, what is the final temperature (in °C) of the metal block?
Answer:
68.6 °C
Explanation:
From conservation of energy, the heat lost by acetone, Q = heat gained by aluminum, Q'
Q = Q'
Q = mL where Q = latent heat of vaporization of acetone, m = mass of acetone = 3.33 g and L = specific latent heat of vaporization of acetone = 518 J/g
Q' = m'c(θ₂ - θ₁) where m' = mass of aluminum = 44.0 g, c = specific heat capacity of aluminum = 0.9 J/g°C, θ₁ = initial temperature of aluminum = 25°C and θ₂ = final temperature of aluminum = unknown
So, mL = m'c(θ₂ - θ₁)
θ₂ - θ₁ = mL/m'c
θ₂ = mL/m'c + θ₁
substituting the values of the variables into the equation, we have
θ₂ = 3.33 g × 518 J/g/(44.0 g × 0.9 J/g°C) + 25 °C
θ₂ = 1724.94 J/(39.6 J/°C) + 25 °C
θ₂ = 43.56 °C + 25 °C
θ₂ = 68.56 °C
θ₂ ≅ 68.6 °C
So, the final temperature (in °C) of the metal block is 68.6 °C.
The final temperature of the metal block is 74.97°C
What is the specific heat?The specific heat of a substance is the required quantity of heat needed to raise the temperature of 1 gram of the substance by 1° C.
From the parameters given:
The mass of acetone = 3.33 gThe number of moles of acetone is:
[tex]\mathbf{= 3.33 g \times \dfrac{mol}{58.08 \ mol}}[/tex]
= 0.0573 mol
At standard conditions, the heat of vaporization of acetone is:
[tex]\mathbf{\Delta H = 32.0 \ kJ/mol \times 0.0578 \ mol } \\ \\ \mathbf{\Delta H = 1.8496 \ kJ } \\ \\ \mathbf{ \Delta H = 1.85 \times 10^3 \ J}[/tex]
Given that:
The mass of the metal (m) = 44.0 gThe initial temperature [tex]\mathbf{T_1}[/tex] = 25° CThe final temperature [tex]\mathbf{T_2 = ???}[/tex]The specific heat of the aluminum is = 0.903 J/g° C
The heat energy can be computed as:
q = msΔT
q = 41 g × 0.903 J/g° C × (x - 25°C)
Using the calorimetry principle, heat energy lost by metal = heat energy gained by acetone.
i.e.
[tex]\mathbf{q_{(acetone)} gain = q_{(metal)} lost }[/tex]
[tex]\mathbf{-1.85 \times 10^3 \ J = - 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]
[tex]\mathbf{1.85 \times 10^3 \ J = 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]
[tex]\mathbf{(x - 25 ^0 C) = \dfrac{1.85 \times 10^3 \ J }{ 41 g \times 0.903 \ J/g^0 C}}[/tex]
[tex]\mathbf{(x - 25 ^0 C) = 49.97^0 C}}[/tex]
[tex]\mathbf{x = 49.97^0 C+25 ^0 C}}[/tex]
x = 74.97 °C
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5. Explain why both diet and regular soft drinks can
damage the enamel on the surface of teeth.
Answer:
diet soda has artificial sugar and regular soda has insane amounts of sugar
The diagram shows a parent hydra with an offsprinly.
Offspring
Which statement best explains why the offspring has no genetic variation
from the parent?
A. It received genes for producing traits different from the parent's.
B. It received a mix of genes from two different parents.
O C. It received genes that are exactly the same as the parent's genes.
O D. It received chromosomes with many different genes.
Answer:
C. It received genes that are exactly the same as the parent's genes
In asexual reproduction in hydra,offspring has no genetic variation from the parent because it received genes that are exactly the same as the parent's genes.
What is asexual reproduction?Asexual reproduction is a type of reproduction where the offsprings are not produced by the combination of genetic material of two individuals which are of different sexes rather they are produced by a single parent.
It is the not the dominant form of reproduction in living beings.Here, the offsprings are identical to their parents as there is no recombination of genetic material.It is observed in both unicellular or multicellular organisms.
There is no fertilization or gamete formation taking place.Types of asexual reproduction include budding, binary fission,fragmentation,etc.
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#SPJ2
If you were to descend through the ocean in a submersible, what changes in the ocean water could you observe?
Answer:
it would become darker. there would be a higher level of water pressure. and there would be less animals, or different alimals.
how can balancing equations support the law of conservation
Answer:
detail is given below.
Explanation:
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
For example:
In given photosynthesis reaction:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
The given equation is balanced chemical equation of photosynthesis. There are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
If equation is not balanced,
CO₂ + H₂O → C₆H₁₂O₆ + O₂
It can not follow the law of conservation of mass because mass is not equal on both side of equation.
can we seperate naphthalene from sugar by filtration to obtain pure sugar?
Answer:
As Naphthalene undergoes sublimation, we use sublimation process. On condensing naphthalene can be separated.
