Answer:
the effects that the scientists are causing by manipulating varuables
A sample of g of pure aluminum metal is added to mL of M hydrochloric acid. The volume of hydrogen gas produced at standard temperature and pressure is
Answer:
V = 11.2L are produced
Explanation:
... Sample of 27g of pure aluminium, 3added to 333 mL of 3.0 M HCl..
Based on the chemical reaction:
2Al(s) + 6HCl(aq) → 2AlC₃(aq) + 3H₂(g)
Where 3 moles of hydrogen are produced when 6 moles of hydrochloric acid reacts with 2 moles of Al.
To solve this question, we need to determine limiting reactant converting each reactant to moles. With limiting reactant and the chemical reaction we can find moles of hydrogen and its volume at STP (T=273.15K; P=1atm), thus:
Moles Al-Molar mass: 26.98g/mol-:
27g * (1mol / 26.98g) = 1mol of Al
Moles HCl:
333mL = 0.333L * (3mol/L) = 1mol HCl
For a complete reaction of 1 mole of HCl are required:
1mol HCl * (2mol Al / 6mol HCl) = 0.333 moles of Al. As there is 1 mole of Al, Al is in excess and HCl is limiting reactant.
Moles of Hydrogen produced are:
1mol HCl * (3 moles H₂ / 6 mol HCl) = 0.5moles H₂ are produced.
Using ideal gas law:
PV = nRT
V = nRT/P
Where V is volume
n are moles: 0.5mol
R is gas constant: 0.082atmL/molK
T is absolute temperature: 273.15K
P is pressure: 1atm.
Solving for V:
V = 0.5mol*0.082atmL/molK*273.15K / 1atm
V = 11.2L are producedways of preventing rusting
Answer:
Here is your answer......
The successive ionization energies for a given element are listed. How many valence electrons does it have?
Answer:
3 valence electrons
Explanation:
Let us first find the amount increased for everything.
From 1st to 2nd, 1048 - 620 = 428
428 increased from 1st to 2nd.
From 2nd to 3d, 2144 - 1048 = 1096
1096 increased from 2nd to 3rd.
From 3rd to 4th, 8724 - 2144 = 6580
6580 increased from 3rd to 4th.
From 4th to 5th, 10141 - 8724 = 1417
From 3rd to 4th, it increased the most. Therefore, we assume that those are the beginning core electrons and not valence electrons. Also, starting from 3rd, they are all core electrons.
For the 1st and 2nd, we can assume they are valence electrons because the kJ/mol didn't increase that much.
Since the core electrons started from the 3rd, we most likely have 3 valence electrons.
So the final answer is 3.
Hope it helped!
what element is this
Answer:
neon
Explanation:
there are 10 protons
A Gold ring is a what?
Element
Compound
Colloid
Alloy
Answer: Alloy
Explanation: gold is an alloy, or mixture of metals
Which is the weakest type of intramolecular force/bond?
a. Polar covalent b. Ionic c. Metallic d. Nonpolar covalent
Answer:
Non polar covlant
Explanation:
Which of the following monosaccharides is not an aldose?
Select one:
a, erythrose
b. fructose
c. glucose
d. glyceraldehyde
Answer:
fructose
Explanation:
because fructose is a ketonic sugar.
g A chemist must prepare of hydrochloric acid solution with a pH of at . He will do this in three steps: Fill a volumetric flask about halfway with distilled water. Measure out a small volume of concentrated () stock hydrochloric acid solution and add it to the flask. Fill the flask to the mark with distilled water. Calculate the volume of concentrated hydrochloric acid that the chemist must measure out in the second step. Round your answer to significant digits.
The question is incomplete, here is the complete question:
A chemist must prepare 550.0 mL of hydrochloric acid solution with a pH of 1.60 at [tex]25^oC[/tex]. He will do this in three steps: Fill a 550.0 mL volumetric flask about halfway with distilled water. Measure out a small volume of concentrated (8.0M) stock hydrochloric acid solution and add it to the flask. Fill the flask to the mark with distilled water. Calculate the volume of concentrated hydrochloric acid that the chemist must measure out in the second step. Round your answer to 2 significant digits.
Answer: The volume of concentrated hydrochloric acid solution is 1.7 mL.
Explanation:
To calculate the hydrogen ion concentration, we use the formula:
[tex]pH=-\log [H^+][/tex]
We are given:
pH = 1.60
Putting values in above equation, we get:
[tex]1.60=-\log [H^+][/tex]
[tex][H^+]=antilog (-1.60)[/tex]
[tex][H^+]=0.0251M[/tex]
To calculate the volume of concentrated solution, we use the equation:
[tex]M_1V_1=M_2V_2[/tex]
where,
[tex]M_1\text{ and }V_1[/tex] = molarity and volume of concentrated acid solution
[tex]M_2\text{ and }V_2[/tex] = molarity and volume of diluted acid solution
We are given:
[tex]M_1=8.0M\\V_1=?mL\\M_2=0.0251M\\V_2=550mL[/tex]
Putting values in above equation, we get:
[tex]8.0\times V_1=0.0251\times 550\\\\V_1=\frac{0.0251\times 550}{8.0}=1.7mL[/tex]
Hence, the volume of concentrated hydrochloric acid solution is 1.7 mL.
9. Which of these is not a mixture? *
Solution
Alloy
Amalgam
They are all mixtures.
Answer:
They are all mixture
Explanation:
last option
How many moles are 5.55 x 104 atoms of Mg?
Answer:
23 atoms. I hope this helped u
Explanation:
How are molecules built?
Bonding
Atomic Rays
Phase Changes
All of these
Number of atoms in 4.5 moles of Au?
How can you identify a redox reaction?
O A. The number of protons has changed in an atom.
O B. Electrons have transferred from one atom to another.
O C. The charges on each side of the equation cancel.
O D. Metal atoms have rearranged in the compounds.
SUBMIT
PREVIOUS
Answer: The Correct Answer is Choice B.
Explanation: I just took the quiz.
ANSWER:
B. Electrons have transferred from one atom to another.
EXPLANATION:
An oxidation-reduction (redox) reaction is a reaction which involves the change in oxidation number of the atoms involved. Since the oxidation number changes, this means that one atom has to lose electrons and another has to accept electrons. The reactant that loses electrons is called REDUCING AGENT while the reactant that gains electrons is called OXIDIZING AGENT.
For example, in a reaction between iron and oxygen as follows:
4Fe+ 3O2→2Fe2O3
Iron is reduced from +2 to 0 because it accepts electrons from oxygen while oxygen is oxidized from -2 to 0 because it transfers electrons to iron.
Hence, a redox reaction can be identified by the transfer of electrons from one atom to another.
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the earth's crust is part of which sphere?
Answer:
Lithosphere
Explanation:
The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below.
MARK ME AS BRAINLIEST PLS
What element corresponds to period 5, group 2
Answer:
Strontium is the second element placed in the 5th period
Hope this will help you if not so advance sorry :)
When baking soda and vinegar react, the surface bubbles. What does this most likely indicate?
a chemical change, because a precipitate is being formed
a chemical change, because a gas is being formed
a non chemical change, because a precipitate is being formed
a non-chemical change, because a gas is being formed
Answer: B
a chemical change, because a gas is being formed
Explanation:
Answer:
B
Mark Brainliest please
Explanation:
Light is a form of _____? A. gamma rays B. sound C. energy D. radio waves
Answer:
Explanation:
Energy
A 52 gram sample of an unknown metal requires 714 Joules of energy to heat it from
30.5◦C to 82◦C. What is the specific heat of
this metal?
Answer in units of J/g ·
◦ C.
Answer: Approximately [tex]0.267 \frac{\text{J}}{\text{g}^{\circ}\text{C}}[/tex]
===================================================
Work Shown:
We have the following variables
Q = 714 joules = heat requiredm = 52 grams = massc = specific heat = unknown[tex]\Delta t[/tex] = 82-30.5 = 51.5 = change in temperaturenote: the symbol [tex]\Delta[/tex] is the uppercase Greek letter delta. It represents the difference or change in a value.
Apply those values into the formula below. Solve for c.
[tex]Q = m*c*\Delta t\\\\714 = 52*c*51.5\\\\714 = 52*51.5*c\\\\714 = 2678*c\\\\2678*c = 714\\\\c = \frac{714}{2678}\\\\c \approx 0.26661687826737\\\\c \approx 0.267\\\\[/tex]
The specific heat of the unknown metal is roughly [tex]0.267 \frac{\text{J}}{\text{g}^{\circ}\text{C}}[/tex]
How many moles of each element are in one mole of Sr(HCO,),? (3 points)
O 1 mole of strontium, 1 mole of hydrogen, 1 mole of carbon, 5 moles of O
O1mole of strontium, 2 moles of hydrogen, 2 moles of carbon, 6 moles of O
O 2 moles of strontium, 2 moles of hydrogen, 2 moles of carbon, 5 moles of O
O2 moles of strontium, 2 moles of hydrogen, 2 moles of carbon, 6 moles of O
Answer: 1 mole of strontium, 2 moles of hydrogen, 2 moles of carbon, 6 moles of O
Explanation: i think i’m not sure
A mole corresponds to the mass of a substance that contains particles of the substance.
The concept of moles are used in various ways:-
Chemical equation. Law of constant proportion.
According to the question, the formula required is:-
[tex]n=\frac{Number\ of\ molecules}{na}[/tex]
The Na is defined as the Avogadro constant is the proportionality factor that relates the number of constituent particles in a sample with the amount of substance in that sample.
According to the question, the compound is [tex]Sr(HCO_{3})_{2}[/tex].
Hence the correct option is 2, that is 1 mole of strontium, 2 moles of hydrogen, 2 moles of carbon, 6 moles of oxygen.
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QUESTION 3 What mass (in g) of glucose, C6H1206, must be added to 300.7 g of water to prepare a 0.322 molal solution? Enter your answer with 3 significant figures and no units.
Answer:
17.42 g of glucose, C₆H₁₂O₆
Explanation:
From the question given above, the following data were obtained:
Mass of water = 300.7 g
Molar solution = 0.322 M
Mass of glucose =.?
Next, we shall convert 300.7 g to L. This can be obtained as follow:
1000 g = 1 L
Therefore,
300.7 g = 300.7 g × 1 L / 1000 g
300.7 g = 0.3007 L
Next, we shall determine the number of mole of glucose in the molar solution. This can be obtained as follow:
Volume of solution = 0.3007 L
Molar solution = 0.322 M
Mole of glucose =?
Molar solution = mole / Volume
0.322 = mole of glucose / 0.3007
Cross multiply
Mole of glucose = 0.322 × 0.3007
Mole of glucose = 0.0968 mole
Finally, we shall determine the mass of glucose, C₆H₁₂O₆, needed to produce prepare the solution. This can be obtained as follow:
Mole of C₆H₁₂O₆ = 0.0968 mole
Molar mass of C₆H₁₂O₆ = (12×6) + (1×12) + (16×6)
= 72 + 12 + 96
= 180 g/mol
Mass of C₆H₁₂O₆ =?
Mole = mass /Molar mass
0.0968 = Mass of C₆H₁₂O₆ / 180
Cross multiply
Mass of C₆H₁₂O₆ = 0.0968 × 180
Mass of C₆H₁₂O₆ = 17.42 g
Thus, 17.42 g of glucose, C₆H₁₂O₆ is needed to prepare the molar solution.
V2S3 chemical compounds?
Answer:
Hence the name of the compound is vanadium (III) sulfide
The chemical symbol for the vanadium(III) sulfide compound is [tex]V_2S_3[/tex]. In this chemical, vanadium (V) is found in +3 oxidation state and sulfur (S) is found in the form of sulphide ions.
The compound contains two vanadium ions, as indicated by the numerical prefix "di-" before the element symbol V. An inorganic compound having a crystal structure that produces a solid is called vanadium(III) sulfide.
It is composed of sulfide anions and vanadium cations arranged in a certain way. Vanadium(III) sulfide has many uses in various industries. It can be used as a catalyst in chemical reactions, as part of some types of batteries, and as a raw material for batteries to produce ceramics and materials with specific electrical and magnetic properties.
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the ______ biodiversity in ecosystem is, the more sustainable it will be.
i think that the more diverse an ecosystem is the more sustainable it will be. do you have a picture of your problem?
The smallest unit of an element, which cannot be broken by any chemical means is called?
atom
compound
element unit
molecule
How many representative particles are in 11.5 moles Ag?
Answer:
24 silver atoms.
Explanation:
11.5 moles of silver atoms will have = 11.5×6.022×1023=6.925×1024 11.5 × 6.022 × 10 23 = 6.925 × 10 24 silver atoms.
Hope this helps!
Brain-List?
According to Avogadro's number, there are 6.926×10²⁴ representative particles in 11.5 moles of silver.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number or number of moles×Avogadro's number=11.5×6.023×10²³=6.926×10²⁴ atoms.
Thus, there are 6.926×10²⁴ representative particles in 11.5 moles of silver.
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Enzymes are catalysts in reactions. What statements describe functions of enzymes?
a. Enzymes are specific in their actions.
b. Once an enzyme binds to a substrate, it cannot be used again.
c. Enzymes lower the energy of activation needed for a reaction
d. Enzymes change the amount of free energy produced
e. Enzyme activity can be affected by temperature.
Answer:
a. Enzymes are specific in their actions.
c. Enzymes lower the energy of activation needed for a reaction
e. Enzyme activity can be affected by temperature.
Explanation:
Enzymes are proteinous structures that acts as biological catalysts in chemical reactions that occur within a system. Like every other catalyst, which speedens the rate of chemical reactions, enzymes possess certain characteristics that makes them have the catalytic nature. They include:
- Enzymes are specific in their actions: Enzymes are substrate-specific, meaning that an enzyme can only act on a substrate it recognizes and binds to.
- Enzymes lower the energy of activation needed for a reaction: Enzymes like other catalyst speed up the rate at which a reaction occurs by lowering the activation energy needed for the reaction to take place.
- Enzyme activity can be affected by temperature: Since enzymes are proteinous i.e made of proteins, they can be easily denatured by temperature. Hence, when exposed to high temperature, enzymes can lose its shape and ultimately its function.
a. Enzymes are specific in their actions.
c. Enzymes lower the energy of activation needed for a reaction
e. Enzyme activity can be affected by temperature.
What are Enzymes?
Enzymes are structures that acts as biological catalysts in chemical reactions that occur within a system. Like every other catalyst, which increases the rate of chemical reactions, enzymes possess certain characteristics that makes them have the catalytic nature. They include:- Enzymes are specific in their actions: Enzymes are substrate-specific, meaning that an enzyme can only act on a substrate it recognizes and binds to.
- Enzymes lower the energy of activation needed for a reaction: Enzymes like other catalyst speed up the rate at which a reaction occurs by lowering the activation energy needed for the reaction to take place.
- Enzyme activity can be affected by temperature: As enzymes are proteinous i.e. made of proteins, they can be easily denatured by temperature. Hence, when exposed to high temperature, enzymes can lose its shape and ultimately its function.
Therefore, option a, c and e are correct.
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Compare the orbital notations of the substances investigated in this experiment with their attraction to the magnet. What unique feature in the orbital notation could be used to predict an attraction to a magnet
Answer:
Number of unpaired electrons
Explanation:
We know that for the compounds listed, the nature of the electrons in the d orbitals affects their interaction with an applied magnetic field.
If there are unpaired d electrons present, the compound is paramagnetic and is more strongly attracted to a magnetic field.
Similarly, if there are paired d electrons, the compound is diamagnetic and is less strongly attracted to a magnetic field.
Using the diagram above, answer the following questions:
6. True or False. The arrow labeled C represents a transfer of chemical energy to mechanical energy. Explain why this is true or false. –
7. True or False. The arrow labeled A represents a transfer of solar energy to chemical energy. Explain why this is true or false. –
8. Which arrow or arrows represent a release of carbon dioxide? What process is occurring at the arrow(s) you selected?
9. Which arrow or arrows indicate a process that cycles carbon from living or nonliving organisms? Describe the process or processes you selected.
10. Which arrow or arrows represent reactions that demonstrate a conservation of mass and energy? Explain your answer.
PLEASE HELP!
Answer:
6. false.
chemical energy to heat and mechanical. Mechanical that runs the factory in the photo, and Heat energy that rises up in the atmosphere to join the other carbon
molecules in the air. 7. True. The arrow letter A is the transfer of solar power
from the sun, to a chemical reaction to produce food for the plant, which is
called photosynthesis. The leaves in the plant has chlorophyll that absorbs light
energy and transforms it to food.8. The answer would be letter C and F. C because It is
during the burning of the fossil fuels that the carbon dioxide is release into
the atmosphere. When burning the fossil fuels the carbon that was inside the
fossils is released. This also happens with diesel and other forms of natural
gas. While, F is because plant
respiration releases some of the carbon remains of the photosynthesis. While
plants do absorb carbon dioxide, part of their end product also includes reformed
carbon dioxide. Most of the other processes in the phot uses carbon or absorbs
carbon dioxide to aid their sustenance.9. A carbon cycle for living things would be A or B to F
wherein the plants absorb carbon dioxide to aid their production of food, and
then releasing carbon dioxide again as a by product of their food production.
This also happen to aquatic plants.An example of a non-living carbon cycle would be, D or E to
C. This would be the absorption of the carbon on our sea waters or to our soil,
this then gets trapped in there until it is release like through the forms of
fossil fuel burning.10. The law of conservation of mass and energy states that
matter can neither be created nor destroyed, this is very much evident in the
carbon cycle. Because the carbon from the light energy from the sun, or in our
atmosphere, ends up back to our atmosphere just to continue its cycle. The fact
that the carbon cycle is a cycle not just a linear equation proves that energy
can neither be created nor destroyed.
Explanation:
The number of electrons in 1.6 gram CH, is:
Answer:
6.022 x 10²³ electrons
Explanation:
What is the systematic name of the following compound?
Li2S
Answer:
the systematic name is called Lithium sulfide.
An inorganic substance composed of the elements lithium (Li) and sulfur (S) is known as lithium sulfide [tex](Li_2S)[/tex].
It is a substance that solidifies in the shape of a crystal. Lithium ions in lithium sulfide have a positive charge, while sulfide ions have a negative charge. The chemical lithium sulfide is important in many industries. It is often employed in the synthesis of various lithium compounds, the manufacture of lithium batteries, and the manufacture of ceramics. Due to their high energy density, lithium batteries are often employed in portable electronics and electric vehicles.
Lithium sulfide is an ionic compound that has a high melting point in terms of physical characteristics. Although it is insoluble in water, many organic solvents can help dissolve it.
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electromagnetic waves can travel through matter as well as across space.
True or false
true becouse i sed so
