Answer:
Explanation:
Atoms are the building blocks of matter.
They are the smallest particles of an element that still have the element's properties.
All atoms are very small, but atoms of different elements vary in size.
Three main types of particles that make up all atoms are protons, neutrons, and electrons.
WHEN YOU SEE A BLUE CAR WHAT COLER IS BEING REFLECTED
Answer:
violet
Explanation:
just violet
oh and you spelled "COLER" wrong, its color or colour if you live somewhere else
Can you think of an example where hydrogen and oxygen combine and release energy with little or no release of heat energy?
When hydrogen and oxygen combine, they form water or hydrogen peroxide, and energy is released in the process.
What are oxygen and hydrogen?
Oxygen and hydrogen are the chemical elements of the periodic table, and they both are gas. Oxygen is the most important gas, which is needed for breathing. It is present at 21% in the atmosphere.
Hydrogen is another gas present in nature. It is the lightest gas, and it has diatomic molecules. It remains gas at normal pressure and temperature, but it becomes liquid at low temperature.
The oxygen and hydrogen readily react and for water, and hydrogen peroxide, the process of reaction of hydrogen and oxygen releases an amount of energy.
Hence, Energy is released during the creation of water or hydrogen peroxide when hydrogen and oxygen mix.
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H.w. balance the following equations:
a) Iron + chlorine → Iron (iii) chloride
b) Nitrogen + hydrogen → Ammonia
c) Phosphoric acid + sodium carbonate → sodium phosphate + water + carbon dioxide
d) Nitrogen dioxide + water + oxygen → Nitric acid
Answer:
3iron + chlorine=iron3 chloride
nitrogen +3hydrogen
Answer:
a) Iron + chlorine → Iron (iii) chloride
3fe+cl__fe3cl
b) Nitrogen + hydrogen → Ammonia
2N+3h2------2NH3
c) Phosphoric acid + sodium carbonate → sodium phosphate + water + carbon dioxide
2H3PO3+3Na2CO3-----2Na3PO4+3H2O+3CO2
d) Nitrogen dioxide + water + oxygen → Nitric acid
NO2+H2O+O2--NOH
sorry if mistake
Why is it necessary to run TLC in a closed container and to have the interior vapor saturated with the solvent? What error is introduced into the determination of an Rf value if the top is left off of the developing chamber?
Answer:
See explanation
Explanation:
Rf value is known as retention factor.The retention factor of a particular material is the ratio of the distance the spot moved above the origin to the distance the solvent front moved above the origin(Harper College).
TLC is carried is out in a closed container and the interior is saturated with the solvent vapor in order to have a maximum resolution between components this prevents solvent from evaporating from the system.
Peradventure the solvent for the separation is partly or wholly lost due to an open container, the Rf value would be lower than the expected value.
On the basis of the information above, a buffer with a pH = 9 can best be made by using
A pure NaH2PO4
B H3PO4 + H2PO4–
C H2PO4– + PO42–
D H2PO4– + HPO42–
E HPO42– + PO43
Answer:
D H2PO4– + HPO42–
Explanation:
The acid dissociation constant for [tex]\mathbf{H_3PO_4 , H_2PO^{-}_4 , HPO_4^{2-}}[/tex] are [tex]\mathbf{7\times 10^{-3}, \ \ 8\times 10^{-8} ,\ \ 5\times 10^{-13}}[/tex] respectively.
[tex]\mathbf{pka (H_3PO_4) = -log (7\times 10^{-3} )=2.2}[/tex]
[tex]\mathbf{pka (H_2PO_4^-) = -log (8\times 10^{-8} )=7.1}[/tex]
[tex]\mathbf{pka (HPO_4^{2-}) = -log (5\times 10^{-13} )=12.3}[/tex]
The reason while option D is the best answer is that, the value of pKa for both
[tex]\mathbf{H_2PO^{-}_4 ,\ \& \ HPO_4^{2-}}[/tex] lies on either side of the desired pH of the buffer. This implies that one is slightly over and the other is slightly under.
Using Henderson-Hasselbach equation:
[tex]\mathbf{pH = pKa + log \Big( \dfrac{HPO_4^{2-}}{H_2PO_4^-} \Big)}[/tex]
The compounds that are used for the formulation of the pH 9 buffer are [tex]\rm H_2PO_4^-\;and\;HPO_4^+[/tex]. Thus, option D is correct.
The buffers are the solutions of acids and base of appropriate pH, that are able to limit the change in pH in the reaction mixture.
Which compound is used for pH 9 buffer?The buffer pH is adjusted with the compounds that has been able to add base or acid to the solution.
For the formulation of buffer of specific pH, the acid and base solutions are required.
The compounds that are used for the formulation of the pH 9 buffer are [tex]\rm H_2PO_4^-\;and\;HPO_4^+[/tex], as they are able to provide acid and base to the solution.
Thus, option D is correct.
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It is the highest point in a wave.
Answer:
Crest is the highest point of a wave
MnO4 - is a stronger oxidizing agent than ReO4 - . Both ions have charge-transfer (LMCT) bands; however, the charge-transfer band for ReO4 - is in the ultraviolet, whereas the corresponding band for MnO4 - is responsible for its intensely purple color. Are the relative positions of the charge-transfer absorptions consistent with the oxidizing abilities of these ions? Explain
Answer:
[tex]$MnO^-_4$[/tex] is a strong oxidizing agent.
Explanation:
The 5d orbitals of Re are higher in energy than 3 d orbitals of Mn. So an LMCT ligand to metal charge transfer excitation requires more energy of [tex]$ReO^-_4$[/tex].
Also, since the molecular orbitals are derived primarily from 3d orbitals of [tex]$MnO^-_4$[/tex] are lower in energy than the corresponding MO's of [tex]$ReO^-_4$[/tex], [tex]$MnO^-_4$[/tex] is better able to accept the electrons.
So it is a better oxidizing agent.
The ligand to metal charge transfer band in ReO4- occurs in the near UV region hence ReO4 - appears colorless.
The electron configuration of Re is Xe 4f14 5d5 6s2 and the electron configuration of Mn is [Ar] 3d5 4s2. We can see that Mn^7+ and Re^7+ have empty d orbitals.
The color of MnO4 - must result from ligand to metal charge transfer hence the purple color of MnO4 -. In the case of ReO4 -, the ligand to metal charge transfer occurs at a much higher energy owing to the fact that 5d orbitals are involved. This transition occurs in the near UV region hence ReO4 - appears colorless. The ligand to metal charge transfer in MnO4- involves lower energy 3d orbitals hence it occurs in the visible region of the spectrum.
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What mass of Iron (III) acetate will be produced when 1.50 grams of iron reacts in acetic acid?
Fe + H(C2H3O2) ® Fe(C2H3O2)3 + H2(not balanced!!)
Answer:
2Fe + 6HC2H3O2 → 2Fe(C2H3O2)3 + 3H2
Explanation:
There you go
A student adds an alka-seltzer to the Koolaid and stirs. The pH meter now reads 8.3. What was released by the alka-seltzer tablet to cause this change?
Answer:
It released hydroxide ions (OH ¯).
Explanation:
A PH of 8.3 indicates that the solution has become a basic solution.
Now, for us to have a basic solution from the addition of an alka-seltzer to Koolaid, it means the Alka-seltzer released plenty of hydroxide ons (OH¯) to the solution.
9. The role of an organism in an ecosystemis called alan
O A. habitat
O B. niche
O C. evolution
D. community
What is the voltage in a circuit is the current is 3 amps and the resistance is 3 ohms
Answer:
9
Explanation:
V=I*R
3*3
Thats the answer
When the number of molecules, atoms, or ions of a particular type (here we consider H ions) is in the hundreds of millions, we can confidently speak of concentrations and analyze an average behavior.
a. True
b. False
Answer:
True.
Explanation:
When the number of molecules, atoms or ions of any element is in the hundreds of millions, we can safely speak of concentrations and analyze a standard behavior, and can even specify the different dilutions used, if there are dilutions. This allows analyzes to be clearly understood by any individual. However, it is not possible to do this if the number of molecules, atoms and ions is very small.
Select the option that best represents recycling food waste
O turning food scraps into biogas
O donating unused food to food pantries
O incinerating leftover food
O feeding scraps to livestock
Answer:
feeding leftover or scraps to livestock
Explanation:
Because feeding leftover healthy food instead of leaving livestock to eat garbage is good for health of the animals and they give good quality of milk, eggs, meat, etc in return
50 POINTS
Which of the following correctly describes a compound?
A. The atoms are bonded together, and the compound has different physical and chemical properties than the individual elements.
B. The atoms have no set ratio for how the atoms can combine, and they are not chemically bonded together.
C. The atoms can only combine in fixed ratios, and they retain their individual chemical and physical properties.
D. The atoms retain their individual chemical properties, and they can only be separated from each other by a chemical change.
Answer: A chemical compound can be described as substance composed of atoms from more than one element held together by chemical bonds in a fixed stoichiometric proportion. A compound has different physical and chemical properties from its constituent elements.
For example : compound water is made up of H and O bonded together and it has different properties from O and H.
Thus, among the given options, the one coreectly describing a compound is
a) The atoms are bonded together, and the compound has different physical and chemical properties than the individual elements.
1. How many molecules are in 4.5 moles?
Answer:
depends on what molecule you are looking for
Explanation:
In one mole of stuff (atoms, molecules, eggses), there are NA individual items of that stuff. So, there are 4.5 × NA BCl3 molecules; i.e. 4.5 × 6.022×1023 ≅ 27×1023 individual molecules of BCl3
Classify each of the following as an example of a mandatory, discretionary, or originator controlled policy, or a combination thereof. Justify your answers.
a. The file access control mechanisms of the UNIX operating system
b. A system in which no memorandum can be distributed without the author's consent
c. A military facility in which only generals can enter a particular room
d. A university registrar's office, in which a faculty member can see the grades of a particular student provided that the student has given written permission for the faculty member to see them.
Answer:
Classifications according to mandatory, discretionary, or originator controlled policy, or a combination thereof:
a. Mandatory
b. Originator
c. Discretionary
d. Mandatory and Originator combined
Explanation:
a) Mandatory control means that access to the UNIX operating system is restricted.
b) Originator controlled policy implies that the memorandum cannot be distributed without the author's consent or permission.
c) Discretionary means that only certain authorized users, for example, generals, can access the particular room.
d) Combined Mandatory and Originator means that while access is restricted to some people, the originator's consent is still required before access can be granted to the faculty member.
in the photosynthesis the energy starts as ___ energy and ends up as___energy
light heat
chemical: chemical
heat light
light chemical
Answer: Light, Chemical
Explanation: This is the answer because "photosynthesis takes place in two stages: the light-dependent reactions and the Calvin cycle. In the light-dependent reactions, which take place at the thylakoid membrane, chlorophyll absorbs energy from sunlight and then converts it into chemical energy with the use of water." - source https://opentextbc.ca/
In the photosynthesis the energy starts as Light energy and ends up as Chemical Energy. Hence option (D) is correct
What is Photosynthesis ?The process by that inexperienced plants and a few different organisms use daylight to synthesize nutrients from carbonic acid gas and water. chemical action in plants usually involves the inexperienced pigment and generates element as a by-product.
Photosynthesis may be a method employed by plants and different organisms to convert lightweight energy into energy that, through internal respiration, will later be discharged to fuel the organism's activities.
photosynthesis takes place in 2 stages: the light-dependent reactions and also the Calvin cycle. within the light-dependent reactions, that manifest itself at the thylakoid membrane, pigment absorbs energy from daylight and so converts it into energy with the employment of water.
Therefore, In the photosynthesis the energy starts as Light energy and ends up as Chemical Energy. Hence option (D) is correct
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In the laboratory, a general chemistry student measured the pH of a 0.328 M aqueous solution of acetylsalicylic acid (aspirin), HC9H7O4 to be 1.987. Use the information she obtained to determine the Ka for this acid.
Answer: [tex]K_a[/tex] for the acid is [tex]3.34\times 10^{-4}[/tex]
Explanation:
[tex]HC_9H_7O_4\rightarrow H^+C_9H_7O_4^-[/tex]
cM 0 0
[tex]c-c\alpha[/tex] [tex]c\alpha[/tex] [tex]c\alpha[/tex]
Give c = 0.328 M and [tex]pH=1.987[/tex]
[tex]1.987=-log[H^+][/tex]
[tex][H^+]=0.0103[/tex]
[tex][H^+]=c\times \alpha[/tex]
[tex]0.0103=0.328\times \alpha[/tex]
[tex]\alpha=0.0314[/tex]
So dissociation constant will be:
[tex]K_a=\frac{(c\alpha)^{2}}{c-c\alpha}[/tex]
Putting in the values we get:
[tex]K_a=\frac{(0.328\times 0.0314)^2}{(0.328-0.328\times 0.0314)}[/tex]
[tex]K_a=3.34\times 10^{-4}[/tex]
Suppose you want to prepare a buffer with a pH of 4.59 using formic acid. What ratio of [sodium formate]/[formic acid) do you need to make this buffer? Formic acid has a K, of 1.8x10 4 Enter your answer to three significant figures.
Answer:
7.08
Explanation:
To solve this problem we'll use the Henderson-Hasselbach equation:
pH = pka + log[tex]\frac{[A^-]}{[HA]}[/tex]Where [tex]\frac{[A^-]}{[HA]}[/tex] is the ratio of [sodium formate]/[formic acid] and pka is equal to -log(Ka), meaning that:
pka = -log (1.8x10⁻⁴) = 3.74We input the data:
4.59 = 3.74 + log[tex]\frac{[A^-]}{[HA]}[/tex]And solve for [tex]\frac{[A^-]}{[HA]}[/tex]:
0.85 = log[tex]\frac{[A^-]}{[HA]}[/tex][tex]10^{(0.85)}[/tex]=[tex]\frac{[A^-]}{[HA]}[/tex][tex]\frac{[A^-]}{[HA]}[/tex] = 7.08The ratio of [sodium formate] to [formic acid] needed to make the buffer is 7.08
How to determine the pKaEquilibrium constant (Ka) = 1.8×10¯⁴pKa =?pKa = –Log Ka
pKa = –Log 1.8×10¯⁴
pKa = 3.74
How to determine the ratio of [sodium formate] to [formic acid]pH = 4.59pKa = 3.74Ratio of [sodium formate] to [formic acid] =?pH = pKa + Log[sodium formate]/[formic acid]
4.59 = 3.74 + Log[sodium formate]/[formic acid]
Collect like terms
4.59 – 3.74 = Log[sodium formate]/[formic acid]
0.85 = Log[sodium formate]/[formic acid]
Take the anti-log of 0.85
[sodium formate]/[formic acid] = anti-log 0.85
[sodium formate]/[formic acid] = 7.08
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5. Write the two resonance hybrids for the carbocation that would be formed by protonation at C-1 of 2-methyl-1,3-pentadiene. Without doing a calculation, would you expect C-2 or C-4 (the two end carbons of the allylic cation) to have the most positive charge on it
Answer:
Follows are the solution to this question:
Explanation:
Please find the complete solution in the attached file.
Methanol has the formula of CH3OH and can be produced by the reaction of carbon monoxide with hydrogen gas. CO + 2 H2 === CH3OH + heat Using the above chemical reaction, determine how each of the following actions would affect the equilibrium of the system. a. heating the mixture b. adding an excess of carbon monoxide c. removing the methanol as it is formed d. adding a substance that reacts with carbon monoxide
Answer:
See explanation below
Explanation:
Let's answer this by parts.
a) As the reaction is naturally exothermic (Exerts heat), increasing temperature means that the reaction will move forward the direction where its absorbing heat
, so the equilibrium will be favored to the reactant side.
b) In this case, the addition of CO, which is a reactant will favor the reaction to the product side. This is because putting more quantity in the reactants will cause that the equilibrium constant K, increase it's innitial value, and this favors the product side.
c) In this case, it happens something similar to case b. This will cause that the reaction will have to work to cover the loss of methanol, therefore, equilibrium will move to the product side too.
d) In this case, we are adding another substance that reacts with CO, so it means that the other reactant is being removed, therefore, the reaction will work to cover this loss but also to cover the adding of the new substance, causing that the K decrease it's value, so equilibrium will be favored to the reactants side.
Hope this helps
the ph of a naoh solution is 12.05. what is the concentration of [oh-] of the naoh solution? express your answer in standard notation
Answer:
0.01 M
Explanation:
NaOH (sodium hydroxide) is a strong base, so it is completely dissociated into ions in aqueous solution:
NaOH ⇄ Na⁺ + OH⁻
So, we have OH⁻ ions in solution.
From the problem, we have the pH value. The pH is calculated as:
pH = -log [H⁺]
As NaOH is a base, we can also calculate the pOH:
pOH = -log [OH⁻]
Thus. we can use the relation between pH and pOH to calculate the pOH and then use it to calculate [OH⁻]:
pH + pOH = 14 ⇒ pOH = 14 - pH = 14 - 12.05 = 1.95
pOH = -log [OH⁻] ⇒ [OH⁻] = [tex]10^{-pOH}[/tex]= [tex]10^{1.95}[/tex]= 0.0112 M ≅ 0.01 M
Answer:
0.0112
Explanation:
They said that was the answer.
how many elements are in 2o2
Answer: hope this helps
Explanation: I’m not sure but after some research here’s what I gathered The molecule has 3 calcium atoms, 2 phosphate atoms and 8 O atoms in it also rate this and pls thank me follow and as as many questions as you need.
What volume (mL) of 0.250 M HNO3 is required to titrate (neutralize) a solution containing 0.276 g of KOH?
Answer:
Volume = 19.68 ml
Explanation:
The equation of the reaction is given as;
HNO3 + KOH ---> KNO3 + H2O
1 mol of HNO3 reacts 1 mol of KOH
Converting 0.276 g of KOH to mol;
Number of moles = Mass / Molar mass
Number of moles = 0.276g / 56.1056 g/mol
Number of moles = 0.00492
Since the mole relationship is 1 = 1;
This means 0.00492 mol of HNO3 reacts with 0.00492 mol of KOH
The relationship between molarity and volume id given as;
Molarity = Number of moles / Volume
Volume = Number of moles / Molarity = 0.00492 mol / 0.250 M
Volume = 0.01968 L
Volume = 19.68 ml
Which of the following statements about steroid hormones is true?
A. They bind with receptor proteins in the plasma membrane.
B. They bind to carrier proteins in order to be transported in the blood to
their target cells.
C. They are synthesized from epinephrine in the adrenal gland.
D. They are mostly derivatives of the amino acid tyrosine.
Answer:
B. They bind to carrier proteins in order to be transported in the blood to
their target cells.
Explanation:
Steroid hormones are belongs to the class of chemical compound called steroid. Steroid hormones are majorly secreted by three glands - ovaries, testes and adrenal cortex.
Steroid hormones are released in the blood and are allowed to bind to the specific carrier proteins such as corticosteroid-binding globulin and albumin which helps them to carry to the target cells for the functioning.
The steroid hormone binds to receptor proteins in the target cell and not in the plasma membrane
Hence, the correct answer is "B. They bind to carrier proteins in order to be transported in the blood to their target cells."
According to the graph, what is the instantaneous speed of the object at 5 seconds? *
Captionless Image
4 m/s
7 m/s
0.25 m/s
3 m/s
Answer:4m/s
Explanation:The reason why that the answer is because I am Smart.
A hydrogen atom is removed from the first carbon atom of a butane molecule and is replaced by a hydroxyl group.
Required:
Draw the new molecule formed.
Answer:
See answer below
Explanation:
In this case, let's draw the butane molecule:
CH₃ - CH₂ - CH₂ - CH₃
According to what the exercise states, we removed an atom of hydrogen from the frist carbon. This could be any of the terminals. I'll grab the first from left to right.
CH₂⁺ - CH₂ - CH₂ - CH₃
When this happens, the atom of carbon is lacking one space and it forms a carbocation.
Followed this step, an hydroxile group replace the atom of hydrogen. The hydroxile is the OH, and when we have an alkane with an OH group in the molecule, we are actually converting this molecule into an alcohol, therefore the molecule formed is:
OH - CH₂ - CH₂ - CH₂ - CH₃Hope this helps
what is the fundamental building unit
Answer:
The basic building blocks that make up matter are called atoms.
I hope it's helpful!
3
A student has a 5.00 gram sample of calcium chloride (CaCl2) solid. How many moles of calcium chloride are
contained in this sample?
Answer: 0.0450 moles of [tex]CaCl_2[/tex]
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
[tex]\text{Number of moles of} CaCl_2=\frac{5.00g}{110.98g/mol}=0.0450moles[/tex]
Thus there are 0.0450 moles of [tex]CaCl_2[/tex]
2.)what is the place value of 7 in 970 123 885
3.)in 292.145,what number is in the thousands place?
4.)what is the place value of 9 in 6547.965?
5.)in 476.8976,what is the
value of underline digi?...si number 7 po naka underline.
Answer:
2.place value is 70 000 00