The Δ Hrxn, in kJ/mol, for this reaction= 11.04 kJ/mol
Further explanationGiven
0.848 g ammonium nitrate
The enthalpy change : +0.117 kJ
Required
Δ Hrxn, in kJ/mol
Solution
Delta H reaction (ΔH) is the amount of heat change between the system and its environment
The value of ° H ° can be calculated from the change in enthalpy of standard formation:
∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)
mass of NH4NO3 = 0.848 g
mol of NH4NO3(MW = 80 g/mol)
mol = 0.848 : 80
mol = 0.0106
The Δ Hrxn :
= 0.117 kJ : 0.0106 mol
= 11.04 kJ/mol
2. Convert 5.3 x 1025 molecules of CO2 to moles.
ANSWER:
moles CO2 = 88 mol
EXPLAIN:
In order to go from molecules of CO2 to moles of CO2, we have to use the following relationship:
I usually set up dimensional analysis questions like this:
Quantity sought = Quantity given x conversion factor
Quantity sought → mol CO2Quantity given → 5.3×1025 moleculesConversion factor → 1mol/6.02×10∧23Now we just plug the values into the format I have above (make sure your units cancel out as you are going through this process, that's how you know if you are doing the calculations correctly or not):
moles CO2 = 5.3×10∧25 molecules×1mol/6.02×10∧23 molecules
moles CO2 = 88 mol
Bohr's model of the atom attempts to explain the idea that
the atom is mostly empty space
O all atoms of one type of element are identical
O energy is quantized
O protons and neutrons are found in the nucleus
Answer:
O energy is quantized
Explanation:
Bohr's model of that atom attempts to explain the idea that energy is quantized within an atomic space.
In 1913 Neils Bohr put forward his own model of the atom based on the quantum mechanics developed by Planck. He suggested that the extranuclear part consists of electrons in specific spherical orbits around the nucleus. As one moves outwards from the nucleus the energy level increases.Give the name of one of the 3 common acids used in chemistry
Answer:
Common strong acids include hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid. Common weak acids include acetic acid, boric acid, hydrofluoric acid, oxalic acid, citric acid, and carbonic acid.
A sample of He has volume of 4.40 L at 555 torr and 33.0 C. Find the new pressure if the volume decreases to 3.50 L and the temperature increases to 44.0 C.
723 torr
504 torr
800. torr
612 torr
Answer:
723 torr
Explanation:
Using the formula;
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (torr)
V1 = initial volume (Litres)
T1 = initial temperature (°C)
P2 = final pressure (torr)
V2 = final volume (L)
T2 = final temperature (°C)
Based on the information provided in this question, V1 = 4.40L, P1 = 555 torr, T1 = 33.0 °C + 273 = 306K, V2 = 3.50 L, P2 = ?, T2 = 44.0 °C + 273 = 317K.
Using the formula above:
555 × 4.4/306 = P2 × 3.5/317
2442/306 = 3.5P2/317
Cross multiply;
2442 × 317 = 306 × 3.5P2
774114 = 1071 P2
P2 = 774114 ÷ 1071
P2 = 722.79
P2 = 723 Torr
A solution is oversaturated,Which could be done to decrease the oversaturation?
dilute the solution
add more solute
cool the solution
add a different solute
A solution is oversaturated,Which could be done to decrease the oversaturation?
dilute the solution
add more solute
cool the solution
add a different solute
Answer:
AAAAAAAAAAAAA i just finished the exam
Explanation:
How do you measure density?
Density over mass
Mass over volume
Volume over density
Mass over density
Answer:
Mass over Volume........
Star A and star B are the same distance away from earth. From earth, star A seems brighter than star B. Which star has the highest absolute brightness?
Answer:
Star B
Explanation:
Star B, this is because, usually in the discussions about stars, the more luminous star or say, the brighter star usually is the one that possesses the smaller absolute brightness.
That being said, succinctly put, if we have two stars A and star B, if star A is brighter than star B, then star A has a lower absolute brightness. Also, if star B is less brighter than star A, then it has the higher absolute brightness.
Answer:
STAR B
Explanation:
How many atoms are in 162.0 g of magnesium?
Answer:
3,938.22
Explanation:
(correct me if I'm wrong)
How many moles of gas would be present in a gas trapped within a 0.1 L vessel at
25.0 °C at a pressure of 2.50 atm?
Answer:
Number of moles = 0.01 mole
Explanation:
Given data:
Volume of gas = 0.1 L
Number of moles = ?
Temperature of gas = 25.0°C
Pressure of gas = 2.50 atm
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
25+273K = 298 K
by putting values,
2.50 atm × 0.1 L = n × 0.0821 atm.L/ mol.K × 298 K
0.25 atm.L = n × 24.47atm.L/ mol
n = 0.25 atm.L /24.47atm.L/ mol
n = 0.01 mol
In some areas of Texas, rainfall quickly soaks through layers of porous rock and is stored naturally underground. The water is then pumped into homes for people to use. What would have the greatest impact on the amount of water available for people in this area?
Explanation:
The amount of rainfall would have the greatest impact on the amount of water available for people in this area. The more the rainfall the more water soaks through layers of porous rocks.Hence, level of water table will remain sufficient for easy pumping of water to the homes.Texas receives plenty of rainfall in a year.In a single year the region can receive up to 48 inches (1,200 mm) of precipitation, and flooding is common near rivers and in low-lying areas. Therefore water table remains intact throughout the year.
Methane is a gas that easily catches fire. This statement is describing a _____.
Answer:
I believe the answer would be chemical reaction.
how many atoms are in 2.45 moles of hydrogen
Answer:
There are 1.4754246675000002e+24 atoms of Hydrogen within the measurement of 2.45 moles of hydrogen!
Explanation:
Balance the Chemical Equation
Pb(OH)2 + HCl ---> H2O + PbCl2
Please help
Answer:
Pb(OH)2 + 2 HCl ---> 2H2o + PbCl2
Explanation:
- How many grams are in 4.6 x 1016 molecules of phosphorus trichloride (PCI)?
Answer:
0.0000101 grams.
Explanation:
First of all, use Avogadro's number to convert from molecules to moles.
Avogadro's number is 6.02 x 10^23.
Second of all, to convert from moles to grams, find the substance formula of phosphorus trichloride. After finding the substance formula, then find the molar mass of phosphorus trichloride.
Phosphorus trichloride is PCl3
Now find the molar mass of PCl3
P = 31.0 amu
Cl = 35.5 amu
They are three chlorine atoms and one phosphorus atom. So you do this.
31.0(1) + 35.5(3) = 137.5 g/mol
Now use dimensional analysis to show your work
4.6 x 10^16 grams of PCl3 * 1 mol/ 6.02 x 10^23 * 137.5 g/mol / 1 mol
The grams and the moles cancel out.
So now do [(4.6 x 10^16) / (6.02 x 10^23)] x 137.5
and you will get 0.000010507
4.6 has the fewest digits which is 2.
So use sig figs and the answer rounds to the nearest millionths.
0.000010507 rounds to 0.0000101
So the final answer is 0.0000101 grams(don't forget the units)
Hope it helped!
Which process is an example of a chemical change?
a. cooking a steak
b. chopping a tree
c. heating a cup of tea
d. drying clothes in the dryer
Answer:
A is the closest thing. You change the composition of the steak. You don't in any of the others.
Explanation:
Usually when you cook something, you are doing something to the composition of the object being cooked. A steak might not be obvious, but boiling an egg should be.
Chopping a tree is something physical. You are removing mass in such a way that the tree will fall. There's nothing chemical about that.
Heating a cup of tea looks like it might be chemical. After all steam is sometimes given off which looks like it is chemical. It's not. The water in the tea is just changing phase.
Drying clothes in a dryer. Again, this looks like something might have changed. After all the mass of the clothes just became less. But all you are doing is separating two masses (leaving one of them behind).
You have a particle of length 68 nm. What is this in meters? ( need help asap)
Answer:
B
Explanation:
how many moles of oxygen atoms are in one mole of the molecule Ca5(PO4)3OH?
Answer:
13
Explanation:
There are 13 moles O in a mole of Ca5(PO4)3OH because there are 13 oxygen atoms in every molecule of Ca5(PO4)3OH. Convert moles oxygen to number of atoms of oxygen. One mole is 6.022*10^23, so your conversion factor would be 6.022*10^23 atoms O/mol O.
Making Sense
1. School bus drivers are extra careful when they cross railroad tracks. They stop before they cross railroad tracks to be sure that there is no
train coming. Yet, trains typically move more slowly through towns than cars do. If trains usually move more slowly than cars, why can
they do more damage if they hit something in their path?
=
2
11
B
1
GO
III
un
III
X2
Saved January 15, 2021 07:35:00 PM
Answer: I think that trains move faster then cars! Buttt, The trains are much stronger and bigger, then cars or trucks. Even if they move slowly they can still crush something smaller then them.
Explanation: ( didnt really understand the question, but i tried)
The reactants of two reactions are shown,
Reaction 1: C and O2
Reaction 2: K2SO4, and CaCl,
Which reaction is likely to be a redox reaction? (1 point)
Only Reaction 2, because potassium and calcium ions will interchange their positions
Both, because the electrostatic charge on cations will change during each reaction
Both, because the electrostatic charge on anions will change during each reaction
Only Reaction 1, because the charge of carbon changes during the reaction
Answer:
Only reaction 1
Explanation:
C + O2 → CO
the charge of C in CO is +2 (oxidation)
from 0 to +2
the charge of O in CO is -2 (reduction)
from 0 fo -2
Hence it is a redox (reduction-oxidation) reaction
This is also valid for,
C + O2 → CO2
the charge of C in CO2 is +4 (oxidation)
charge increases from 0 to +4
the charge of O in CO2 is -2 (reduction)
charge decreases from 0 to -2
hence, it is a redox reaction
K2SO4 + CaCl → KCl + CaSO4
none of the charges changes in this reaction
please recheck, for this may not be the correct answer
Determine the empirical formula for a compound with 68.4% Cr and 31.6% O. Show your work in the space below.
Answer:
Cr2O3
Explanation:
To find the empirical formula, which is the smallest whole number ratio of a compound, the following is done:
68.4% Cr = 68.4g of Chromium
31.6% O = 31.6g of Oxygen
Since, Cr = 52, O = 16, divide each mass by their respective atomic mass to convert to moles.
Cr = 68.4/52 = 1.315 mol
O = 31.6/16 = 1.975 mol
- Next, we divide each mole value by the smallest value (1.315mol)
Cr = 1.315/1.315 = 1
O = 1.975/1.315 = 1.50
The ratio or Cr to O is 1:1.5
We multiply this ratio by 2 to get the whole number ratio as follows:
2 × 1: 2 × 1.5
2:3
Hence, the empirical formula of Cr and oxygen is Cr2O3.
If you mix aqueous solutions of potassium nitrate and iron(II)sulfate what will be the precipitate, if there is one at all?
Answer:
No one will precipitated because these all are soluble in water
Explanation:
2KNO3 + FeSO4 -----> K2SO4 + Fe(NO3)2
Which elements are found only along a zigzag line that divides columns 13 through 18 on the periodic table?
A. Metalloids
B. Metals
C. Nonmetals
D. Representative metals
Answer:
A. Metalloids.
Explanation:
Metalloids. Metalloids, also called semiconductors, are the elements that border the zigzag line on the periodic table.
Is Ni(NO3)3 ionic or covalent and why
The Ni ( NO₃ )₃ is an anhydrous covalent compound. Ni ( NO₃ )₃ is prepared by the reaction of red fuming nitric acid and nickel nitrate hemihydrate.
What is covalent compound ?An electron exchange that results in the formation of electron pairs between atoms is known as a covalent bond. Bonding pairs or sharing pairs are the names given to these electron pairs. Covalent bonding is the stable equilibrium of the attractive and repulsive forces between atoms when they share electrons.
At room temperature, covalent compounds can be found in all three of their physical states and often have low boiling and melting temperatures. Because covalent compounds lack charged particles with the ability to carry electrons, they do not conduct electricity.
Two atoms sharing a pair of electrons make a covalent connection. Because the electron pair is drawn to both nuclei, the atoms are kept together.
Thus, The Ni ( NO₃ )₃ is an anhydrous covalent compound.
To learn more about covalent compound, follow the link;
https://brainly.com/question/21505413
#SPJ2
How do you draw a lewis structure?
Answer:
How to Draw a Lewis Structure.
Step 1: Find the Total Number of Valence Electrons.
Step 2: Find the Number of Electrons Needed to Make the Atoms "Happy".
Step 3: Determine the Number of Bonds in the Molecule.
Step 4: Choose a Central Atom.
Step 5: Draw a Skeletal Structure.
Step 6: Place Electrons Around Outside Atoms.
Explanation:
Hope this helped! :)
HELLLPPPPPPPPPP
Match each substance with either acid or base.
Lemon juice:
Baking soda:
Ammonia:
Vinegar:
PLZ DON'T GUESS THE ANSWER
Answer:
Lemon Juice - Acid
Baking Soda - Base
Ammonia - Base
Vinegar - Acid
Which section of the ocean floor is near the coastline of all continents
why water is not used as a thermometric substance
Answer:
Water can be used as the thermometric liquid. It expands and contracts with temperature so it can be used. It's just not a very good choice because: It's thermal expansion is not very large compared to other liquids like mercury.
Explanation:
Hope this help
Someone please tell me what the epithelial tissue does. This question gives you 20 points btw if you answer
Answer:
They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception
Explanation:
They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception
. The kidneys are _______________ to the liver.
a. Dorsal
b. Ventral
c. Medial
d. Superior
HEEEEELP PLZ
Which conclusion is most logical, based on the data?
Answer:
its the last one
Answer:
D
Explanation: