Answer:
4.5 × 10²³ number of atoms Al
Explanation:
Given data:
Mass of Al = 20 g
Number of atoms of Al = ?
Solution:
The given problem will solve by using Avogadro number.
'It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance" .The number 6.022 × 10²³ is called Avogadro number.
We will calculate the number of moles of Al first:
Number of moles = mass/molar mass
Number of moles = 20 g/ 27 g/mol
Number of moles = 0.74 mol
1 mole = 6.022 × 10²³ number of atoms
0.74 mol × 6.022 × 10²³ number of atoms / 1 mol
4.5 × 10²³ number of atoms Al
The required number of atoms is [tex]4.46\times 10^{23}[/tex]
Atomic Weight:Atomic weight, also called relative atomic mass, ratio of the average mass of a chemical element’s atoms to some standard.
Given that,
Mass=[tex]20[/tex] grams
1 mole of aluminum [tex]= 27g = 6.023\times10^{23}[/tex] number of atoms 27g of aluminum contains [tex]6.023\times10^{23}[/tex] a number of atoms.
Therefore,20 grams the number of atoms is,
[tex]6.023\times10^{23}\times\frac{20}{27} =4.46\times10^{23}[/tex]
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which common substance is an acid?
Answer:
sulfuric acid, phosphoric acid, and nitric acid, citric acid
Explanation:
what is the correct parent name for an organic compound just one carbon
Answer:
Meth- its full name is Methane
Explanation:
1 methane
2 ethane
3 propane
4 butane
5 pentane
6 hexane
7 heptane
8 octane
9 nonane
10 decane
11 undecane
12 dodecane
How many moles of Nitrogen in 40.0 g of N2O?
.14 g
25.5 g
14.5 g
Answer:
To do this question. we first have to find the mass% of nitrogen in N2O and then, using that percentage, we can simply find the number of moles of N from the number of moles of N2O
Mass % of Nitrogen:
Mass% of nitrogen = (Molar mass of N2 / Molar mass of N2O)*100
Mass% nitrogen = (28 / 44)*100
Mass% of Nitrogen = 0.63 * 100
Mass% nitrogen = 63%
Mass of Nitrogen:
So, now we can say that in any given mass of N2O. 63% of the total mass is the mass of Nitrogen
Hence, total mass * 63/100 = Mass of Nitrogen
Replacing the variables
40 * 0.63 = Mass of Nitrogen
Mass of Nitrogen = 25.2 grams
Which of the following is an example of a reaction that you've seen in your everyday life?
Question 5 options:
Ice melting
Salt dissolving
Water freezing
Fire burning
Answer:
water freezing
Explanation:
i think so
In the modern Periodic Table of the Elements, in order of what property are the elements arranged?
atomic number?
date of discovery?
number of neutrons?
Reactivity with hydrogen?
Answer:
They are organized by atomic number, hence the reason for 1,2,3,4, you get where im goin'?
Explanation:
Aspirin is not as____
in water as sugar is.
Answer:Soluble
Explanation:Soluble:(of a substance) able to be dissolved, especially in water.
Common human behavior that seems to be programmed or directed by genes or hormones?
Answer:
There's a lot...lying...rolling eyes...aggression...mating...parenting...sadness...basically alot
Explanation:
What reagent is
used to test for starch
Answer:
iodine
Explanation:
In the presence of starch, iodine turns a blue/black colour. It is possible to distinguish starch from glucose (and other carbohydrates) using this iodine solution test. For example, if iodine is added to a peeled potato then it will turn black. Benedict's reagent can be used to test for glucose.
1. The elements in a compound
a. Combine by reacting with each other
b. Join in a specific ratio
c. Can be separated using chemical means
d. All of the above
Answer:
d.All of the above
Explanation:
They can do all of the above
Foods cook faster when placed in a pressure cooker. This is because the pressure on the surface of the water is
Answer:higher than and higher than
Explanation:
Determine the volume of 200 g of hydrogen gas.
Which statement best describes the nuclear model of the atom. A) negative charges dispersed in a positively charged cloud B) positive charges dispersed in a negatively charged cloud C) small, dense positive nucleus surrounded by a diffuse negatively charged cloud D) small, dense negative nucleus surrounded by a diffuse positively charged cloud
Answer:
D.) small, dense negative nucleus surrounded by a diffuse positively charged cloud
Explanation:
I am not 100% sure but the reason I think this is the answer is because Protons and Neutrons are in the nucleus. Protons being positively charged and neutrons being negatively charged. Again, I do not know for sure, but I think D is the answer.
The statement that best describes the nuclear model of the atom is C) small, dense positive nucleus surrounded by a diffuse negatively charged cloud.
The atom is made up of 3 kinds of particles: protons, neutrons and electrons.
Protons (positive charge) and neutrons (zero charge) are in the nucleus, which concentrates 99% of the mass of the atom in 1% of the space. This is why is it positive and very dense.
Electrons (negative charges) are orbiting the nucleus in diffuse negatively charged clouds known as orbitals.
The statement that best describes the nuclear model of the atom is C) small, dense positive nucleus surrounded by a diffuse negatively charged cloud.
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Which of the following could not be responsible for the acceleration of an object?
wind
gravity
density
friction
Answer:
i believe its friction
Explanation:
friction slows down objects
What is the end
result of a chemical reaction?
Chemical reactions occur when chemical bonds between atoms are formed or broken. The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products.
The end of a chemical reaction is the product.
What is a chemical reaction?
A chemical reaction contains a reactant that reacts to form products. The reactant can be more than two, and the product can be two or more.
Food spoiling is a chemical reaction because it has an unpleasant odor, taste, and color change. Fruits undergo a chemical shift as they ripen. For instance, both the texture and color may change.
When we balance a chemical process, the number of moles or atoms on the left must match the amount on the right. Thus, the atoms participating in such a chemical process are discovered to have mass.
Chemical elements are uncontaminated by impurities or other elements and are pure substances made up of just one type of atom. They are found in the crust of the earth. Carbon, hydrogen, and oxygen are some examples.
Therefore, the end is the product.
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Order the steps required to extract a dichloromethane solution with aqueous hydrochloric acid.
Transfer the "Organic Layer" back to the empty separatory funnel.
b. Add an equivalent volume of aqueous acid to the dichloromethane layer in the separatory funnel.
h. Label this beaker "Aqueous Layer".
Remove the cap.
Label the beaker "Organic Layer".
Make sure the stopcock is closed.
Repeat all steps. Drain the bottom layer into a labeled beaker.
C. Cap the separatory funnel with a glass or Teflon stopper.
e. Place the separatory funnel back in the Iron ring.
Remove the funnel from the iron ring and shake vigorously to mix the layers, periodically venting to release pressure. Drain the remaining liquid into a labeled beaker. Suspend a separatory funnel using an iron ring and ring stand. g.
Allow the layers to physically separate in the funnel. Transfer the organic (dichloromethane) layer to the funnel.
The formatting of the question is a bit scrambled: I'm not sure if there are separate steps that have been unintentionally consolidated into a seemingly discrete step, nor am I sure which letters actually correspond with which step(s). So, for clarity's sake, I treated every sentence as its own step and arranged all of them accordingly. Hopefully, you can then reorganize them according to the labeled steps as you have been provided.
Suspend a separatory funnel using an iron ring and ring stand. Make sure the stopcock is closed. Transfer the organic (dichloromethane) layer to the funnel. Add an equivalent volume of aqueous acid to the dichloromethane layer in the separatory funnel. Cap the separatory funnel with a glass or Teflon stopper. Remove the funnel from the iron ring and shake vigorously to mix the layers, periodically venting to release pressure. Place the separatory funnel back in the Iron ring. Allow the layers to physically separate in the funnel. Remove the cap.Drain the bottom layer into a labeled beaker. Label the beaker "Organic Layer". Drain the remaining liquid into a labeled beaker. Label this beaker "Aqueous Layer". Transfer the "Organic Layer" back to the empty separatory funnel. Repeat all steps.Notes:
The letters have been replaced with numbers only to clarify the order of the steps. No changes were made to the steps themselves, including any stylistic errors.A very few set of sequential steps might be interchangeable, but the steps as separated and organized above is in accordance with standard liquid-liquid extraction protocol.Determining which layers are the "organic" and "aqueous" layers (i.e., whether the organic/aqueous layer, or vice-versa, is on the bottom/top ) is a nontrivial step; for this reason, when actually doing such extractions, the beakers (or whatever vessel) into which the layers are drained at any step are sometimes labeled "top layer" and "bottom layer" in case you misidentify which layers are, in fact, the organic and aqueous layers. Oftentimes, the organic layer is on top of the aqueous layer as many common organic solvents are less dense than water. Halogenated organic solvents, like dichloromethane, are one of the exceptions, and so will generally comprise the bottom layer.A system initially has a pressure of 12 atm and a volume of 9 L. What is the volume if the pressure is decreased to 6 atm?
Answer:
The answer is 18 LExplanation:
In order to find the volume , we use the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the final volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
From the question
P1 = 12 atm
V1 = 9 L
P2 = 6 atm
We have
[tex]V_2 = \frac{12 \times 9}{6} = \frac{108}{6} \\ [/tex]
We have the final answer as
18 LHope this helps you
True or False: A chemical reaction ALWAYS results in a ne product being formed
Answer:
True
Explanation:
A chemical reaction will always result in a new product or substance being formed
that is what makes it a chemical reaction.
This image represents what?
A) Atom of nitrogen
B) mixture of nitrogen atoms
C) compound containing nitrogen
D) molecule of diatomic nitrogen
Answer:
IT’S D)molecule of diatomic nitrogen
Explanation:
Thx to the person above though..........
Answer:
D
Explanation:
HURRY PLEASE HELP!! The combustion of methane begins with 1 carbon atom and 4 hydrogen atoms in the compound CH4 How many hydrogen atoms will be
found as a product?
A. 3
B. 4
C. 1
D. 2
Answer:
B, 4.
Explanation:
i just took this
How many moles of sodium sulfate are present in .100 g of the compound?
2.126 x 10^-3 mol
174.3 mol
7.040 x 10^-4 mol
Answer:
7.040 x 10^-4 mol
Explanation:
A gas in a large syringe has a volume of 300ml at 45°C. The temperature is lowered to 30°C. What is the new volume of the gas in the syringe? (N and p are constant). Hint:Convert temperature to kelvin before calculating (°C+273=K)
Answer:
V1=300ml
V2= x ml
T1= 45 Celsius
T2= 30 celcius
Do the math....
you will get
318x=90900
divide by 318
x=285.8 ml (rounded)
Explanation:
you have to add 45 and 30 (separately because the temp. has to be in kelvin) to 273... so V2 equals 2858.8 ml
The energy associated with motion is
a. kinetic energy
b. elastic potential energy.
c. gravitational potential energy.
d. nuclear energy
Answer:
Kinetic Energy
Explanation:
The form of energy associated with the motion, position, or shape of an object is called mechanical energy. An object's mechanical energy is a combination of its potential energy and its kinetic energy. The basketball has both potential energy and kinetic energy.
30 points!! please help chem question
the state of y at room temperature is gas, good luck!
Will IO- and NaOH form a buffer?
Answer:
this is the answer for will NaOH be a buffer
Explanation:
The compound CH 3NH 3Cl is a salt made from that weak base, so the combination of these two solutes would make a buffer solution. NH 3 is a weak base, but NaOH is a strong base. The combination of these two solutes would not make a buffer solution
Particles in a warmer block will have ________ kinetic energy and move ______than the particles in the colder block.
Question options:
more/faster
less/slower
less/faster
more/slower
Answer:
More and Faster
Particles in a warmer block will have more kinetic energy and move faster than the particles in the colder block.
What is kinetic energy?
Kinetic energy is defined as a form of energy that an object or particle has by the reason of its movement.
It is also defined as the measure of the work that an object does by the virtue of its motion.
Kinetic energy can be expressed as
KE = 1/2mv²
Kinetic energy is produced when potential energy is released, triggered into motion by gravity, or chemical reaction among other crystals.
Thus, particles in a warmer block will have more kinetic energy and move faster than the particles in the colder block.
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how many oxygen atoms are there in six dinitrogen monoxide molecules? express your answer as an integer
Answer:
6 oxygen atoms
Explanation:
Step 1: Given data
Number of dinitrogen monoxide molecules (N₂O): 6
Number of oxygen atoms (O): ?
Step 2: Calculate the appropriate ratio
The ratio of dinitrogen monoxide molecules to oxygen atoms is 1:1.
Step 3: Use the ratio to calculate the number of oxygen atoms
6 molecule N₂O × (1 atom O/1 molecule N₂O): 6 atom O
1. An oxide of chromium is found to have the following % composition: 68.4% Cr
and 31.6% 0. Determine this compound's empirical formula.
Answer:
Empirical formula is Cr₂O₃.
Explanation:
Given data:
Percentage of Cr = 68.4%
Percentage of O = 31.6%
Empirical formula = ?
Solution:
Number of gram atoms of Cr = 68.4 / 52 = 1.3 2
Number of gram atoms of O = 31.6 / 16 = 1.98
Atomic ratio:
Cr : O
1.32/1.32 : 1.98/1.32
1 : 1.5
Cr : O = 1 : 1.5
Cr : O = 2(1 : 1.5)
Empirical formula is Cr₂O₃.
Earth is a single interconnected system. True False
Answer:
True
Explanation:
Earth is a single interconnected system but it can be subdivided into smaller systems.
Fran finds a dark-colored rock that she identifies as basalt. Which property gives the rock its dark color?
O its shape
O its banding
its grain size
O its mineral content
Answer:
Mineral Content.
Explanation:
shape has nothing to do with the color displayed.
Nor does the grain size.
I don't know what banding is. Whatever it is, it is not the answer.
D: mineral content.
Which of the following is an example of a buoyant force acting on a piece of
bread?
O A. The piece of bread floats on the surface of a lake.
B. The piece of bread travels in uniform circular motion.
C. The piece of bread remains still despite an applied force.
D. The piece of bread travels with straight-line horizontal
acceleration.
An example of the buoyant force on a piece of bread is the piece of bread floats on the surface of body water such as a lake.
What is the buoyant force?This is a force experienced by objects when they are in a body of water. This force implies objects have an upward force, which in many cases causes them to float.
What are some examples of this force?Any object that is submerged in water but floats or shows to have an upward force is an example of this force. Based on this, the option that clearly shows the buoyant force is a bread floating on a lake.
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Answer:
A
Explanation: