Answer:
B.
Explanation:
I just did the edge nuity assignment
A sample of unknown pressure occupies 0. 776L at a temperature of 298K. The sample of gas is then tested under known
conditions and has a pressure of 32. 6 kPa and occupies 0. 664L at 303K. What was the original pressure of the gas?
A. 27. 43 kPa
B. 38. 62 kPa
C. 58. 73 kPa
D. 84. 11 kPa
Answer: A. 27.43 kPa
Explanation:
Use the formula: PV/T = PV/T →
P(.776) / (298) = (32.6)(.664) / (303) →
.0026P = .07144 →
P = 27.43 kPa :)
How is a precipitate evidence for a chemical reaction?
Formation of precipitate is usually an evidence of a chemical change. The precipitate is a new substance that gets created due a chemical reaction between two or more different substances. The precipitate can be the formation of a solid within a liquid or the formation of a solid within a solid due to a chemical reaction or change. The solid formation within a liquid is known as precipitate. This kind of chemical reaction can be seen in normal and daily life, as well as in laboratories.
Can some one help me ASAP with the 3rd and 4th answer please! This is due at 7:30 in the morning
Answer:
3. add water to develop the procedure.
4. of course,, because sugar dissolves and sand does not.
why Kw does not change when the concentration of hydrogen ions increases
Answer:
hope it helps...
Explanation:
it is determined by the concentration of hydrogen ions, the percentage of hydrogen ions contained in the solution.
Let's take water as an example.
As you know, the formula for water is H2O. Most of the molecules in water are in that extremely stable form we know as H2O.
However, a very tiny percentage of those molecules have broken up into hydrogen ions (H+) and hydroxide ions, (OH-), as illustrated in the figure.
Actually, this balance of hydrogen ions and hydroxide ions determines the pH of the water.
When the hydrogen ions outnumber the hydroxide ions, the solution is acidic. If the reverse is true, then the solution is alkaline.
In pure water, the hydrogen ion (hydroxonium ion) awareness has to be equal to the hydroxide ion awareness. For every hydrogen ion fashioned, there may be a hydroxide ion shaped as nicely which means that you can update the [OH-] term inside the Kw expression with some other.
What occurs when the concentration of hydrogen ions increases?As the awareness of hydrogen ions in the solution grows, the greater acidic the solution becomes. As the extent of hydroxide ions will increase the greater primary or alkaline, the solution turns into.
Learn more about hydrogen ions here: https://brainly.com/question/26424076
#SPJ2
An atom contains 15 protons and 17 neutrons. How many electrons does this atom have and what is its atomic number?
Number of electrons: Atomic Number:
Answer: Electrons: 15 Atomic number :15
Explanation:
which element has the same electron configuration as the following:
1s22s22p63s23p64s23d104p65s24d
Lab Report
Ocean Currents
It’s time to complete your Lab Report. Save the lab to your computer with the correct unit number, lab name, and your name at the end of the file name (e.g., U2_ Lab_OceanCturrents_Alice_Jones.doc).
Introduction
What was the purpose of the experiment?
Type your answer here:
Answer:
The purpose of the experiment is to see how water of different temperature and salinity affect the density.
Explanation:
Temperature and salinity directly affect the density of the water. Water of low temperature is more dense than water of high temperature, BUT, (fresh)water with no salt is less dense than (sea)water with more salt, so temperature and salinity change density of water.
Answer:
Please post the answers for the other questions on my page!! I will give you brainiest!! Please :(
Explanation:
Can someone identify all these crystals?
Ah, yes, these are all very special, and have different looks and textures, to learn about these awesome rocks,
Take a look at the chart shown.
Can y’all just list 3 evidence for evolution. Total 3 sentences!!!
(WILL MARK BRAINLIEST) promise :)
:D
Off the top of my head I only have one example of evolution on humans lol
Wisdom teeth
Explanation:
Our ape-like ancestors used to use wisdom teeth to chew on bark and other hard foods. Today, we don't use them at all, and we're even at the point that some people are born with no wisdom teeth at all.
Answer:
Evolution is a change in the genetic makeup of a population over time.
A few evidences are:
Anatomy. Species may share similar physical features because the feature was present in a common ancestor (homologous structures).
Molecular biology. DNA and the genetic code reflect the shared ancestry of life. DNA comparisons can show how related species are.
Biogeography. The global distribution of organisms and the unique features of island species reflect evolution and geological change.
Fossils. Fossils document the existence of now-extinct past species that are related to present-day species.
Direct observation. We can directly observe small-scale evolution in organisms with short lifecycles.
Hope this helps! :D
do all isotopes decay over time ?
Certain naturally occurring radioactive isotopes are unstable: Their nucleus breaks apart, undergoing nuclear decay. ... All elements with 84 or more protons are unstable; they eventually undergo decay. Other isotopes with fewer protons in their nucleus are also radioactive.
these are materials that allow heat to flow easily
Answer:
materials that allow heat to flow easily conductors of heat. For examples, aluminum, iron and copper.
Explanation:
Hope it helps!!!
How does desert pavement form?
Answer:
A common theory suggests that desert pavements are formed through gradual removal of sand and other fine particles by the wind and intermittent rains leaving behind the large fragments. ... Once the pavement is formed the removal of fine particles ceases because the pavement acts as a barrier to further erosion.
Explanation:
60 point! please help me please!
Answer:
[tex]\huge\boxed{\sf 21.6\ moles\ of\ MgO}[/tex]
Explanation:
Here,
for 1 mol of O₂, 2 moles of MgO are produced.
Also,
At STP:
1 mol of O₂ = 22.4 dm³/mol molar value
Moles in 242 L of O₂:
= volume / molar value
= 242 / 22.4
= 10.8 mol
Since:
1 mol of O₂ = 2 moles of MgO
10.8 mol of O₂ = 2 × 10.8 moles of Mgo
10.8 moles of O₂ = 21.6 moles of MgO
[tex]\rule[225]{225}{2}[/tex]
help asap If an engine does 200 J of work in 5 s, how much power was generated?
A. 4 W
B. 4000 W
C. 40 W
D. 400 W
[tex]p = \frac{e}{t} [/tex]
where e is the energy.
& t is the time.
[tex]p = \frac{200}{5} = 40 \: w[/tex]
How much energy is required when a 142.1 gram sample of aluminum goes from 25.5°C to 46°C? (the specific heat of aluminum is 0.90 J/g °C).
Answer:
2621.75 j heat is required to increase the temperature 25.5°C to 46°C.
Explanation:
Given data:
Mass of sample = 142.1 g
Initial temperature = 25.5°C
Final temperature = 46°C
Specific heat capacity of Al = 0.90 J/g.°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 46°C - 25.5°C
ΔT = 20.5°C
Q = 142.1 × 0.90 J/g.°C × 20.5°C
Q = 2621.75 j
Thus, 2621.75 j heat is required to increase the temperature 25.5°C to 46°C.
what is an element?
Answer:
an element is a substance that cannot be broken down into any other substance. each element is made up of its own type of atom, which is why each element is different and unique than the other.
Answer:
In chemistry, an element is a pure substance which cannot be broken down by chemical means, consisting of atoms which have identical numbers of protons in their atomic nuclei. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number
hope this helps! :) :) :)
The carbon atoms in cellulose found in a log originally came from _____ absorbed by the plant. Group of answer choices
Answer: Your answer is carbon dioxide in the air
Hope this helps!
a 50.o mL beaker contains 680. g mercury what is the density of mercury?
Answer:
13.6 m/v
Explanation:
d=m/v
d=680/50
d=13.6
ЗАl2(SO4)3
How many oxygen atoms are present?
Answer:
12 oxygen atoms
Explanation:
Multiply 3x4 and get 12 that's the easiest way I can explain it lol
Cells in this organism have different functions (jobs). Unicellular Organism or Multicellular Organism?
Answer:
Multicellular Organism
Explanation:
Unicellular organisms are made of one cell. For example, bacteria. Multicellular organisms are made up of more than one cell. For example, humans.
If the entire organism is one cell, that one cell carries out all the functions. In contrast, we have different cells to carry out different jobs. E.g. blood cells, skin cells, stomach cells and many more.
Is helium and neon a noble gas?
Answer: Yes
Helium (He) and Neon (Ne) are both noble gases. They are very common in our lives. Helium has a atomic number of 2, and neon has one of 10.
Hope this helps you!
write chemical equation of zinc granule
Thermochemical Equations Project: Modeling Energy Changes
DOES ANYONE HAVE THIS DONE AND IS WILLING TO SEND MY WAY. NEED ASAP. ON EDGE.
Answer:
In this assignment, you will write and balance a chemical equation. Then,you will use a table of enthalpy values to calculate the energy change in the reaction. Next, you will create a model of the energy change in the reaction.Finally, you will write an explanation that describes the energy change in the reaction.
Explanation:
In the diatomic molecule HCl, the H and the Cl share a pair of
electrons. By doing so, the hydrogen atom attains the electron
configuration of while chlorine attains the electron
configuration of
Answer:
helium and argon
Explanation:
The helium dimer is a van der Waals molecule containing two helium atoms with the formula He2. This chemical is the biggest diatomic molecule, which is a molecule made up of two atoms that are bound together. This dimer's connection is so weak that it will break if the molecule spins or vibrates too much.The noble gases (helium, neon, argon, krypton, xenon, and radon) are also monatomic gases at STP. To distinguish them from other gases that are chemical compounds, homonuclear diatomic gases and noble gases are referred to as "elemental gases" or "molecular gases."Oxygen gas is prepared in the laboratory through the catalytic decomposition of hydrogen peroxide. Define a catalyst
Answer:
Catalyst:
Explanation:
A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
Calculate the volume of an object that has a mass of 20.00 g and a density of 2.45 g/cm^3.
Answer:
2450000 gram
Explanation:
v= m × ρ= 1 cubic meter × 2.45 gram/cubic centimeter= 1000000 cubic centimeter × 2.45 gram/cubic centimeter= 2450000 gram
Explanation:
v=m over D
mass=20.oog
Density=2.45g
20.00-2.45
ans is 17.46
Which of the following is a possible pH for distilled water that has lime (a base) dissolved in it?
a. 1
b. 3
c. 7
d. 9
Answer:
Explanation:
Distilled water has a pH of 7. Anything below that is acidic. One is very acidic. So a b and c cannot be the answer.
Lime is a base. That means that when it is put in water, the pH is going to be greater than 7,
The only possible answer is D
this element has a mass of 500.5 g. How much
volume does it have?
Answer:
element A has a mass of 2 units, while an atom of element B
has a mass of 5 units, what would be the mass of the
compound A3 B2
Explanation:
how would you separate salt and sugar
Answer:
Evaporation
Explanation:
If the water is completely evaporated we will get separated sugar from the mixture. If we dissolve the mixture in alcohol we will get the salt separated while sugar will be dissolved in alcohol.
Aluminum has a specific heat of 0.900 J/(g°C). How much energy in kJ is needed to raise the temperature of a 625 g block of aluminum from 30.7°C to 82.1°C?
Answer:
About 28.9 kJ.
Explanation:
Recall the formula for specific heat:
[tex]\displaystyle q = mC\Delta T[/tex]
Where q is the amount of heat released, m is the mass of the substance, C is its specific heat, and ΔT is the change in temperature.
Therefore, by substitution, we have that:
[tex]\displaystyle \begin{aligned} q & = (625\text{ g})\left(\frac{0.900 \text{ J}}{\text{g-$^\circ$C}}\right)\left(\frac{1 \text{ kJ}}{1000 \text{ J}}\right) \left(82.1^\circ\text{C}-30.7^\circ \text{C}\right) \\ \\ & = (625\text{ g})\left(\frac{0.900 \text{ J}}{\text{g-$^\circ$C}}\right)\left(\frac{1 \text{ kJ}}{1000 \text{ J}}\right)(51.4^\circ\text{C}) \\ \\ & = 28.9\text{ kJ}\end{aligned}[/tex]
In conclusion, about 28.9 kJ of energy is needed.