Explanation:
b. What useful functions do oxidation numbers serve?
It is used to show oxidation and reduction (loss and gain of electrons)
b. How many molecules are in 1 mole of molecules?
1 mole = 6.022 * 10^23 molecules
c. What is the name given to the number of molecules in 1 mole?
Avogadro's Number of molecules
21. a. What is the molar mass of an element?
This is the mass of an element divided by the number of moles.
Molar mass = Mass / Number of moles
b. Write the molar mass rounded to two decimal places of carbon, neon, iron and uranium.
amu = Atomic Mass Unit
Carbon = 12.01 amu
Neon = 20.18 amu
Iron = 55.85 amu
Uranium = 238.03 amu
How many moles are in 281 g of Ca(OH)2?
Answer:
3.79 moles
Explanation:
To convert moles to gams of a substance we need to find the molar mass of the substance. For Ca(OH)₂ th molar mass is:
1Ca = 40.08g/mol
2O = 2*16g/mol = 32g/mol
2H = 2*1.01g/mol = 2.02g/mol
The molar mass is:
40.08g/mol + 32g/mol + 2.02g/mol = 74.1g/mol
And moles are:
281g * (1mol / 74.1g) =
3.79 molesWhich system controls organs in times of stress?
Answer:
The autonomic nervous system has a direct role in physical response to stress and is divided into the sympathetic nervous system (SNS), and the parasympathetic nervous system (PNS). When the body is stressed, the SNS contributes to what is known as the “fight or flight” response.
Explanation:
According to Banquo, the King "Sent forth great largess to your offices." What
gift does King Duncan bring for Lady Macbeth?
Answer:
Diamond
Explanation:
The answer is gotten from Act 2, Scene 1 of the play by Shakespeare titled "Macbeth". In this scene, we see that Banquo met Macbeth late in the night where they had a profound conversation about the gift of diamond which king Duncan had given to Banquo to deliver to Macbeth.
What holds more salt warm or cold water?
Why is Newton's first law of motion is sometimes called the law of inertia
Answer:
The reason why Newtons first law of motion is sometimes called the law of inertia is because it states that if the object is in motion, it will not rest unless an unbalanced force acts on the object.
what kind of chemical reaction is this?
Please someone help me ...............
Answer:
Q58. number of moles(n) and relative formula mass(Mr)
Q59. a) 2 H2S + O2 --> 2 H2O + 2 S
b) After the balanced equation you should able to draw it yourself - I cannot draw it on here :)
Explanation:
help plsssssssssssssssssssssss
Answer:
b chemical - thermal and mechanical
Explanation:
energy stored in food in is chemical, so it would only make sense of b) was the answer
What 3 things will you do to dissolve a solid (salt) faster in a liquid (water)
Answer:
There are three ways to make solids dissolve faster: Break the solute into smaller pieces. Stir the mixture. * Heat the mixture.
Explanation:
Substances can dissolve in water three ways—by dissociation, dispersion, and ionization.
Which reactions are oxidation-reduction reactions? Check all that apply.
(1) 2 upper N a plus upper C l subscript 2 right arrow 2 upper N a upper C l.
(2) Upper P b (upper O upper H) subscript 2 right arrow upper P b upper O plus upper H subscript 2 upper O.
(3)Upper C u plus 2 upper A g upper N upper O subscript 3 right arrow upper C u (upper N upper O subscript 3)subscript 2 plus 2 upper A g.
(4)Upper Z n upper B r subscript 2 plus 2 upper A g upper N upper O subscript 3 right arrow 2 upper A g upper B r plus upper Z n (upper N upper O subscript 3) subscript 2.
(5)Upper C upper H subscript 4 plus 2 upper O subscript 2 right arrow upper C upper O subscript 2 plus upper H subscript 2 upper O.
answer- 1,3, & 5
explanation- I did it on edge 2021
Answer:
the 1st 3rd and 5th ones
EDGE 2021
Explanation:
Answer:
A
C
E
Explanation:
a 2.7 L of N2 is collected at 121kpa and 288 K . if the pressure increases to 202 kpa and the temperature rises to 303 K , what volume will the gas occupy?
Answer:
The gas will occupy a volume of 1.702 liters.
Explanation:
Let suppose that the gas behaves ideally. The equation of state for ideal gas is:
[tex]P\cdot V = n\cdot R_{u}\cdot T[/tex] (1)
Where:
[tex]P[/tex] - Pressure, measured in kilopascals.
[tex]V[/tex] - Volume, measured in liters.
[tex]n[/tex] - Molar quantity, measured in moles.
[tex]T[/tex] - Temperature, measured in Kelvin.
[tex]R_{u}[/tex] - Ideal gas constant, measured in kilopascal-liters per mole-Kelvin.
We can simplify the equation by constructing the following relationship:
[tex]\frac{P_{1}\cdot V_{1}}{T_{1}} = \frac{P_{2}\cdot V_{2}}{T_{2}}[/tex] (2)
Where:
[tex]P_{1}[/tex], [tex]P_{2}[/tex] - Initial and final pressure, measured in kilopascals.
[tex]V_{1}[/tex], [tex]V_{2}[/tex] - Initial and final volume, measured in liters.
[tex]T_{1}[/tex], [tex]T_{2}[/tex] - Initial and final temperature, measured in Kelvin.
If we know that [tex]P_{1} = 121\,kPa[/tex], [tex]P_{2} = 202\,kPa[/tex], [tex]V_{1} = 2.7\,L[/tex], [tex]T_{1} = 288\,K[/tex] and [tex]T_{2} = 303\,K[/tex], the final volume of the gas is:
[tex]V_{2} = \left(\frac{T_{2}}{T_{1}} \right)\cdot \left(\frac{P_{1}}{P_{2}} \right)\cdot V_{1}[/tex]
[tex]V_{2} = 1.702\,L[/tex]
The gas will occupy a volume of 1.702 liters.
What is the percent composition of Br in CuBr3?
Answer:
about 79% (79.04369332 to be exact)
Explanation:
Percent composition=(Molar mass of element x amount of it)/Molar mass of compound x 100
Br= 3 x 79.9/303.25 x100=79.04369332
Which of the following is an example of acceleration?
A. A boat sits on a boat trailer.
B. A car moves in a straight line at 60 km/hr.
C. A plane moves in air at a steady speed of 850 km/hr.
D. A bus moves on a straight road and then
makes a right turn.
Answer:
it's either B. or C.. hope this helps!
Explanation:
Answer:
D. A bus moves on a straight road and then makes a right turn.
Explanation:
Acceleration is a change in direction or speed. All of the other examples involve straight lines or constant speed.
How many particles are in one mole of copper (II) sulfate, CuSO4?
True or False: The reactants and the products of a chemical equation always have the same number of atoms.
Answer: True
Explanation: It always has the same number because the both have or are using the same product.
The genetic information found in DNA, chromosomes, and determines
A. the traits of the organism
B. the organism as an animal
C. the safety of the nucleus
D. the type of cell
Answer:
a
Explanation:
the traits of the organism
The effective nuclear charge of a neutral atom aluminum, Al with atomic number 13 is
Answer:
wala hindi ko yan alam ty
If a reaction is endothermic,
1 point
More energy is released when the bonds in the products are formed than is used to
break the bonds in the reactants
The temperature increases
The same amount of energy is used to break the bonds of the reactants as is released
when the bonds in the products are formed
О O
It takes more energy to break the bonds of the reactants than is released when the
bonds in the products are formed
Answer: It takes more energy to break the bonds of the reactants than is released when the bonds in the products are formed
Explanation:
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat. Thus it takes more energy to break the bonds of the reactants than is released when the bonds in the products are formed
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat. Thus More energy is released when the bonds in the products are formed than is used to break the bonds in the reactants
When magnesium is added to hydrochloric acid, a gas is formed. Explain what happens in the reaction, how the gas is collected and how it could be tested to prove what it is.
Answer:
Explained below.
Explanation:
Formula when magnesium reacts with hydrochloric acid is given by;
Mg(s) + 2HCl(aq) = MgCl2(aq) + H2(g)
So, from the equation, we can see that the gas formed is hydrogen.
This hydrogen gas is collected by a method known as water displacement.
This gas can be tested for by holding a burning splint near to the top of the test container. The resulting effect should be a high pitched pop sound because the hydrogen gas will react with the oxygen gas in the air to result in a small explosion.
How many grams are there in 9.03 x 1023 molecules of CO2?
Answer:
The correct answer is - 66g.
Explanation:
Given:
molecules of CO2 = 9.03 x 10^23
We know:
1 mole of any substance = 6.02x10^23 molecules. (Avogadro's number)
M (CO2) = 12 + (2x16) = 12 + 32 = 44g
Solution:
The mass of CO2 with 9.03x10^23 molecules would be:
44g of CO2 = 6.02x10^23 molecules.
So, the mass in grams of CO2 (X) = 9.03x10^23 molecules
Xg of CO2 = (44x9.03x10^23)/6.02x10^23 = 66g
Thus, the correct answer would be - 66gm.
Calculate the percent by mass of benzene in a solution containing 14.2 g of benzene in 28.0 g of
carbon tetrachloride
Answer:
33.65%
Explanation:
total weight of solution=14.2+28=42.2g
benzene=14.2/42.2*100=33.65%
A doctor tapes a patients knees with a hammer to test the reflex which can provide information about the condition of the _____
Answer:
lol this is what you get for not answering my question and stealing points
Explanation:
If each image represents one mole of the substance pictured, which contains the greatest
amount of substance?
A)molecules
B) atoms
C)formula units
D)none; all amounts are the same
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, all amounts are the same. The correct option is option D.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Calculating the amount of a chemical in grams from moles is among the most often chemistry computations. You will employ the mole ratio of reactants to reagents when balancing equations.
Therefore, all amounts are the same. The correct option is option D.
.To know more about mole, here:
https://brainly.com/question/15209553
#SPJ2
How much sugar can be dissolved of the 0.3 ml of water is heated to 1000C?
Please help me on this.
Answer: true
Explanation:
i hope this helps
How many lone pairs are in SO4 2-
Answer:
None
Explanation:
There are two S=O. bonds and two S-O bonds in sulfate ion lewis structure. Sulfur atom is the center atom and four oxygen atoms are located around sulfur atom. There are no lone pairs in the last shell of sulfur atom.
If the mass of all the reactants in a chemical reaction is 100g, what will the mass of all products be?
To investigate the effect of salt water on a cell, a researcher places one cell sample in freshwater and a second cell sample in salt water. After six hours, the researcher observes and sketches the two cells as shown. What change in the cells occurred during the six hours the cells remained undisturbed? A.Osmosis occurred in the salt water cell sample because the water from inside the cell moved out of the cell to a lower concentration, causing the cell to shrink. B.Osmosis occurred in the freshwater cell sample because the water from outside the cell moved into the cell to a higher concentration, causing the cell to grow. C.Osmosis occurred in the salt water cell sample because the salt from outside the cell moved into the cell to a lower concentration, causing the cell to shrink. D.Osmosis occurred in the freshwater cell sample because the salt from inside the cell moved out of the cell to a higher concentration, causing the cell to grow.
Answer:
MARK ME BRAINLIEST
Explanation:
MARK ME BRAINLIEST
For the reaction, ?N2 + ?H2 → ? NH3,
What is the maximum amount of NH3 which could be formed from 12.26 mol of N2 and 2.11 mol of H2? Answer in units of mol.
Explanation:
➢number of moles. Moles and Chemical Reactions. Chapter 4. 3 H2. + N2. →. 2 NH3 ... How many grams of NH3 would form if 2.11 moles of N2 reacted with ...
Which system is responsible for the production of red blood cells?
hormone erythropoietin (EPO) is responsible for the production of red blood cells.