The mole is used in chemistry
A) to count large numbers of very small particles, such as atoms or molecules.
B) to relate the mass and the number of particles of a substance to each other.
C) to relate the mass and the volume of a substance to each other.
D) all of these are true.
Is magnesium reacting with oxygen an exothermic reaction?
Answer:
is it a yes or no question
if it is yes
Explanation:
for an electron to move from an energy level that was close to the nucleus to an energy level that is far from the nucleus would it need to gain or lose energy ?
Answer:
it would need to lose energy
Explanation:
I don't really have an explanation
As the electrons gets closer to the nucleus, by the electrostatic force of attraction electrons are tightly bound to the nucleus. To move the inner electron to outer shell, high energy have to applied to weaken the nuclear force.
What is nuclear force?Nuclear force is the force by which the nucleon are bind in the nucleus and electrons are attracted towards the nucleus. The positively charged protons inside the nucleus electrostatically attracts the negatively charged electrons.
The minimum amount of energy required to remove an electron from the valence shell by overcoming the nuclear force is called ionization energy.
To bring an electron which is closer to the nucleus to the outer shell needs much energy to reduce the nuclear attractive pull. The energy need to gain.
Find more on ionization energy:
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I need help working these
Answer:
1) 7.80 X 10^22[tex]\frac{1}{6.02*10^{23} }[/tex] = .13
2) 5.6 [tex]\frac{6.02*10^{23} }{1}[/tex] = 3.4 X 10^24
3)3.81 [tex]\frac{1}{74.55}[/tex] X [tex]\frac{6.02*10^{23} }{1}[/tex] = 3.08 X 10^22
4) 399.91 [tex]\frac{4.05*10^{23} }{6.02*10^{23} }[/tex] = 269
5)4.32 [tex]\frac{1}{18.01}[/tex] X [tex]\frac{22.4}{1}[/tex] = 5.37
Explanation:
For 2 the correct answer is 3.4 instead of 3.2. The 3.4 is rounded from 3.37. Sadly I couldn't figure out the bonus.
The number 6.02 x 1023 is called...
i need help what is the name for 6.02 x10^23
El salmón percibe la presencia del 2-feniletanol (C5H5-CH2-CH2-OH) en el agua, en cantidades tan bajas como 0.03 mole en cien trillones (1*10^18) de litros de agua, ¿cuál es la masa, en gramos, de esa sustancia? ¿Qué cantidad de moléculas equivale a esa sustancia?
Answer:
3.66 g de 2-feniletanol (C5H5-CH2-CH2-OH)
1.8 * 10 ^ 22 moléculas
Explanation:
Sabemos que podemos obtener la masa de una sustancia a partir del número de moles presentes de la siguiente manera;
número de moles = masa / masa molar
masa molar de 2-feniletanol (C5H5-CH2-CH2-OH) = 122,16 g / mol
masa = 0.03 moles * 122.16 g / mol = 3.66 g de 2-feniletanol (C5H5-CH2-CH2-OH)
Si 1 mol = 6.02 * 10 ^ 23 moléculas
0.03 moles = 0.03 moles * 6.02 * 10 ^ 23 moléculas = 1.8 * 10 ^ 22 moléculas
15 points
5. CFC's
A. are short for chlorofluorocarbons
B. are man-made chemicals
C. attack the ozone layer
D. all of the above
Answer:
D. all of the above
Explanation:
it is short for chlorofluorocarbons,are man-made chemicals and attack the ozone.
Now you will focus on a second hypothesis. This hypothesis can be very similar to the first, but this time you want to focus only on the second variable in question, speed. What could be a hypothesis that would illustrate the relationship between speed and kinetic energy? Use the format of "if…then…because…” when writing your hypothesis.
Answer:
If the mass of an object increases, then its kinetic energy will increase proportionally because mass and kinetic energy have a linear relationship when graphed.
Explanation:
is correct answer
Answer:
Sample Response: If the speed of an object increases, then its kinetic energy will increase proportionally because speed and kinetic energy have a linear relationship when graphed.
Explanation:
What is the molar mass of carbon?
give reason unit of volume is a derived unit
Answer:
A derived unit is defined as the unit that is created from a product of SI base units. Volume is an example of derived unit because it is not possible to measure volume directly using any measuring device For eg., Volume of water in bucket is can not be measured using rule, or scale, or any other measuring device.
Hence, volume is a derived unit.
Can someone help me plz!!!
Calculate the mass, in grams, of 2 moles of CaCl2.
Answer:
222.2 grams of CaCl2 in 2 moles
Explanation:
Mole=given mass/gram mass formula
2moles=x/Gram Mass Formula
(Gram Mass Formula of CaCl2):
Ca=40.1
Cl= 35.5 x 2= 71
-----------------------
GFM=111.1
2 moles = x/111.1 g
x=222.2
What is the reactant(s) in the chemical equation below?
Answer:
C. 3CO(g) + Fe2O3(s)
Explanation:
The substance(s) to the hath left of the arrow in a chemical equation art hath called reactants. A reactant is a substance yond is presenteth at the starteth of a chemical reaction. The substance(s) to the right of the arrow art hath called products. A product is a substance yond is presenteth at the endeth of a chemical reaction
So in this example, 3CO(g) + Fe2O3(s) art the reactants.
The 2Fe(S) + 3CO2(G) art the products.
Desire I holp! Has't a most wondrous day!
Hope I helped! Have a great day!
Natural Causes of Climate Change:
Pick one cause of natural climate change. Explain what it is and how
it causes dimate change. What is the effect of the climate change?
Helpp plzzz
Answer:
cause of climate change: The earth's climate is affected and changed through a lot of natural causes like volcanic eruptions.
how it causes change: Volcanoes can be extremely dangerous to earth because it can impact climate change. During major explosive eruptions huge amounts of volcanic gas, aerosol droplets, and ash are injected into the stratosphere.
what is the effect of the change: Major eruptions alter the Earth's radiative balance because volcanic aerosol clouds absorb terrestrial radiation, and scatter a significant amount of the incoming solar radiation, an effect known as "radiative forcing" that can last from two to three years following a volcanic eruption.
i hope you get it correct!! <3 can i plz get a brainlest!
How the lead (II) carbonate can be separated and collected from the product mixture with ammonium nitrate?
Answer:
fgedhwkmgfvhcdnxj
Explanation:
gtryijdohuygfvbhgfy
The pressure in a bicycle tire is 105 psi at 25˚C in Fresno. You take the bicycle up to Huntington, where the temperature is – 5˚C. What is the pressure in the tire?
Answer:
94.4 Psi
Explanation:
Given that;
P1 = 105 psi
T1 = 25˚C + 273 = 298 K
P2 = ?
T2 = – 5˚C + 273 = 268 K
P1/T1 = P2/T2
P1 T2 = P2T1
P2 = P1T2/T1
P2 = 105 * 268/298
P2= 94.4 Psi
chemistry question help please
Answer:
xii. B. Smelting
xiii. D. Carbon
Explanation:
Smelting is known to be a process by which a metal is gotten. It is gotten either as the element or as a simple compound. This is obtained from metal's ore by heating. The heating can be done ordinarily in the presence of oxidizing agents, like air, or reducing agents, carbon e.g coke.
Zinc is gotten after Zinc oxide is heated in the presence of carbon.
This process is smelting.
Concentrated tetraoxosulphate acid is a strong dehydrating agent. It has the ability to char wood, paper, or sugar, leaving a carbonaceous residue. The charring effect is as a result of the carbon that is found in the wood.
The acid sucks in the oxygen and hydrogen, leaving behind the carbon; this results in the charring effect.
According to the chemical formula shown below, all of the following elements are found in phosphoric acid EXCEPT
A. Hydrogen
B.Oxygen
C.Phosphorus
D.Potassium
Please asap i need help
PLS HELP THIS IS DUE TODAY!!
Answer:
I think it would be Yellow
If the [OH-] of a solution is 2.7 x 10-4 mol/L the pOH of the solution is
Answer:
14/2.1 thats just what i do
Explanation:
If the [OH⁻] of a solution is 2.7 × 10⁻⁴ mol/L the pOH of the solution is 3.569.
What is pH ?pH is used to measure whether the substance is acidic, basic or neutral and the range is 0-14.
How to find the pOH of the solution ?To calculate the pOH it is expressed as:
pOH = - log[OH⁻]
= - log[2.7 × 10⁻⁴]
= - [log 2.7 + log 10⁻⁴] [log a × b = log + log b]
= - [log 2.7 - 4 log 10] [log aˣ = x log a]
= - [log 2.7 - 4 × 1] [log 10 = 1]
= - [log 2.7 - 4]
= - [0.431 - 4]
= - [-3.569]
= 3.569
Thus, from above conclusion we can say that If the [OH⁻] of a solution is 2.7 × 10⁻⁴ mol/L the pOH of the solution is 3.569.
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48g of magnesium and 32g of oxygen react to form 80g of magnesium oxide. 2Mg + O2 --> 2MgO What mass of oxygen is needed to make 20g of MgO?
Answer:
8g
Explanation:
1mole of oxygen -->2moles MgO
32g --> 80g
?g --> 20g
(20x32)÷80
= 8g oxygen
Answer:
Mass of oxygen needed = 8 g
Explanation:
Given data:
Mass of oxygen needed = ?
Mass of MgO formed = 20 g
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of MgO:
Number of moles = mass/molar mass
Number of moles = 20 g/ 40 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of MgO and O₂:
MgO : O₂
2 : 1
0.5 : 1/2×0.5 = 0.25 mol
Mass of oxygen needed:
Mass = number of moles × molar mass
Mass = 0.25 mol × 32 g/mol
Mass = 8 g
If a sample of gas of valume 605 mL and temperature of 39 OC, has 0,00803 moles. What is it’s pressure?
Answer:
The pressure of the gas is 0.35 atm.
Explanation:
We can find the pressure of the gas by using the Ideal Gas Law:
[tex] P = \frac{nRT}{V} [/tex]
Where:
V: is the volume = 605 mL = 0.605 L
n: is the number of moles = 0.00803 moles
T: is the temperature = 39 °C = 312 K
R: is the gas constant = 0.082 L*atm/(K*mol)
Hence, the pressure is:
[tex] P = \frac{0.0083 moles*0.082 L*atm/(K*mol)*312 K}{0.605 L} = 0.35 atm [/tex]
Therefore, the pressure of the gas is 0.35 atm.
I hope it helps you!
a clown in the park gave a child a balloon filled with 7.00 L of helium at 301 K. What will the volume of the balloon be when the child takes it into an air conditioned house at 295 K?
Answer:
6.9L
Explanation:
Brent is doing research to make a type of baby bottle out of plastic that is free from harmful chemicals. What type of research is this?
Applied
Descriptive
Quantitative
Experimental
Answer:
Applied
Explanation:
Since Brent is using his existing scientific knowledge to create a new product or invention then this falls under the category of Applied Research. Applied research includes using any theoretical or proven information in order to create something physical that can be used in our real-life world. Usually, this research focuses on solving a problem through the use of technology. Thisis exactly what Brent is trying to do by creating a new plastic that does not have harmful chemicals that can hurt babies in the long term.
Answer:applied
Explanation:
How many grams of KClO3 will dissolve in 300g of water at 50°C?
Answer:
50 g
Explanation:
Please brainiest
Does anyone know what I should put for number 2 if you KNOWW plssss
What patterns do you notice between the three maps? Using the concepts
you've learned in this lesson, construct an explanation for these patterns in your
Science Notebook or in the space below.
Answer:
A spatial pattern is a perceptual structure, placement, or arrangement of objects on Earth. It also includes the space in between those objects. Patterns may be recognized because of their arrangement; maybe in a line or by a clustering of points.
Explanation:
Most of the volume of a gas is ______________________.
Group of answer choices
A. a vacuum
B. dark
C. gone
D. empty space
Please help!
Answer:
D. empty space
Explanation:
Most of the volume of a gas is empty space, which allows gases to be easily compressed. Gas particles are in constant motion, moving rapidly in straight paths. When gas particles collide, they rebound and travel in new directions. Every time they hit the walls of the container, they exert pressure.
PLEASE ANSWER ASAP!!!!!!!!!!!! The Relative Surface Gravity is 27.551 on _____.
Saturn
the Moon
the sun
Jupiter
Answer:
its the sun
Explanation:
The substance that cannot be broken down into a simpler form by ordinary chemical means is called a __ ?
Answer:
Elements
Explanation:
An element is any substance that cannot be broken down into simpler form by ordinary chemical means.
Elements are distinct substances that cannot be split up into simpler substances. .
Such substances consist of only one kind of atom. There are over hundred elements known till date. Elements are made up of unique atoms. In a chemical reaction, elements combines and rearranges.
How many molecules are equal to 10.35 g of pyridine?
Answer:
0.78× 10 ²³ molecules
Explanation:
Given data:
Mass of pyridine = 10.35 g
Number of molecules = ?
Solution:
Number of moles of pyridine:
Number of moles = mass/molar mass
Number of moles = 10.35 g/ 79.1 g/mol
Number of moles = 0.13 mol
Number of molecules;
1 mole contain 6.022× 10 ²³ molecules
0.13 mol × 6.022× 10 ²³ molecules / 1mol
0.78× 10 ²³ molecules