Answer:
There is 0.75moles in the solution
Answer:
Explanation:
concentration=no.of moles/volume in dm3
which is
1.5mol/dm3 multiply by 500/1000
=0.75moles
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]
Which of the following would best be classified as a chemical change? *
Firecracker explosion
Freezing water into ice
Magnetizing a nail
Alcohol evaporating on your skin
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
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]
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.
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
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.
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!
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:
Which of the two waste products from combustion has been known to cause
harmful changes to our environment?
a. CO2
b. H2O
I need help on this question
Answer:
The way its parts are arranged ....I think
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.
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!
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!!!
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.
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! :) :) :)
Please help brainiest is award.
Answer:
4
Explanation:
nonmetals are brittle and dull.
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 :)
write chemical equation of zinc granule
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:
Select all 3 of thy chemical properties below:
A Malleable
B Flammable
c Ductile
D Toxicity
E Density
F Oxidation
G Boiling/Melting Point
Answer:
B.
F.
Explanation:
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:
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.
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."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:
do chemical equations with no reaction still have to be balanced
Answer:
The same number of atoms of each element must appear on both sides of a chemical equation. However, simply writing down the chemical formulas of reactants and products does not always result in equal numbers of atoms. You have to balance the equation to make the number of atoms equal on each side of an equation.
Explanation:
how many moles is 784.616 g of H2SO4?
Take the given weight (784.616g) and divide it by the atomic weight of H2SO4.
The atomic mass can be found under the element symbol on the periodic table. You must add the atomic mass for each element in H2SO4 to get the total. The total atomic mass for H2SO4 will be about 98g.
Then divide the weight by this number.
784.616g/98g = 8.006 moles
Therefore, there is approximately 8 moles.
witch color has the longest wavelength
Answer:
Red light.
Explanation:
On one end of the spectrum is red light, with the longest wavelength. Blue or violet light has the shortest wavelength. White light is a combination of all colors in the color spectrum. It has all the colors of the rainbow.
Answer:
red
Explanation:
red has a wavelength of 630-700 nm
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.