Answer:
4Al + 3O2 ------> 2Al2O3
the mole ratio is 4:2
you divide 250 by 2
you get 125 and that's the mass produced
Can you please help me it’s not a hard question
The atomic number of calcium is 20. This number means that calcium has 20 protons. The atomic mass of calcium is 40. How many neutrons does calcium have? (Remember: protons + neutrons = atomic mass.)
ASAP NOW PLS
Answer:
Otherwise, positive charge means that the element lost an electron and negative charge means it gained an electron. (3) The atomic mass is equal to the sum of the number of protons and number of neutrons. An atom of the calcium-40 isotope has 20 neutrons in its nucleus.
500mL of air are trapped in a tube over mercury at 25°C. It is found that, after six
days, the air has expanded so that 32mL have escaped the tube. What total
temperature change occurred over this period if the pressure remained constant?
Answer:
The new temperature is 19.072 K.
Explanation:
Charles's Law consists of the relationship that exists between the volume and the temperature of a certain quantity of ideal gas, which is maintained at a constant pressure. This law says that as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases because the temperature is directly related to the energy of the movement of the gas molecules.
In summary, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the quotient that exists between the volume and the temperature will always have the same value:
[tex]\frac{V}{T}=k[/tex]
Assuming that a certain volume of gas V1 that is at a temperature T1 at the beginning of the experiment varies up to a volume of gas V2, then the temperature will change to T2, and it will be true:
[tex]\frac{V1}{T1}=\frac{V2}{T2}[/tex]
In this case:
V1= 500 mLT1= 25 C= 298 KV2= 32 mLT2= ?Replacing:
[tex]\frac{500 mL}{298 K}=\frac{32 mL}{T2}[/tex]
Solving:
[tex]T2=32 mL*\frac{298 K}{500 mL}[/tex]
T2= 19.072 K
The new temperature is 19.072 K.
Which statement about Bohr’s model of the atom is false?
A. Electrons cannot be between energy levels.
B. Electrons orbit the nucleus.
C. An electron’s path is not known exactly.
D. Electrons exist in energy levels.
The statement which is false about Bohr's model is option C, "an electron's path is not known exactly". Electron's path can be determined using the knowledge of different energy levels.
What are energy levels?Energy levels in an atom is circular paths having fixed energy through which the electrons are revolving around the nucleus. This model of atom was proposed by Niels Bohr.
According to Bohr's atomic model, electrons are revolving through fixed energy levels around the nucleus, where the velocity and momentum of electron and the radius of the atom can be determined using the model.
Bohr's model of atom contributed well to the atomic structure and helped to determine the energy of electronic transitions.
Hence, the statement an electron's path is not known is false.
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which one is? Will give brainliest
Answer: 2Cr + 3Br2 Yields 3CrBr3
Explanation:
We know that 4a is not balanced because there are 3 Nitrogen atoms on the reactants side and 2 on the products side.
We know that 4c is not balanced because there are 4 Chlorine atoms on the reactants side and 2 on the products side. (Remember there are 2 Cl2 atoms. Therefore, 2 times 2 means there are 4 Chlorine atoms on the reactants side)
Finally, we know the answer is not 4d because there is 1 Potassium on the reactants side and 2 potassiums on the products side.
Therefore, the answer must be 4b, which contains 2 Chromium atoms and 6 bromine atoms on each side
1. identify a metal that matches each of the following descriptions. There may be more than one possible metal.
a Reacts slowly with cold water to form a hydroxide.
b Does not react with oxygen when heated.
c Reacts slowly with dilute acid.
d Reacts very vigorously in cold water to form hydroxide.
Answer:
I don't think there is any metal matches with this condition
5. Para la siguiente reacción: KClO3 (s) KCl(s) + O2
Si se descomponen 500 gramos de una muestra impura de clorato de potasio y se recogen 100 litros de O2 medidos bajo condiciones normales de presión y temperatura. Determine la pureza de la muestra.
Answer:
72.95%
Explanation:
Para resolver esta pregunta, debemos hallar las moles tóricas que se producirían en la reacción asumiendo que los 500g son únicamente de clorato de potasio haciendo uso de la reacción balanceada:
2KClO₃(s) → 2KCl(s) + 3O₂(g)
Donde dos moles de clorato de potasio producen tres moles de oxígeno.
Después de hallar las moles teóricas de oxígeno debemos hallar las moles producidas usando PV = nRT. La pureza SERÁ:
Moles producidas / moles Teóricas * 100
Moles clorato -Masa molar: 122.55g/mol-:
500g KClO₃ * (1mol / 122.55g) = 4.08 moles KClO₃
Moles O₂ teóricas:
4.08 moles KClO₃ * (3 moles O₂ / 2 moles KClO₃) = 6.12 moles
Moles producidas:
PV / RT = n
Donde P = 1atm a STP
V es volumen = 100L
R es constante de los gases = 0.082atmL/molK
T =273.15K a STP
Reemplazando:
1atm*100L / 0.082atmL/molK*273.15K = 4.46 moles
La pureza de la muestra es:
4.46 moles / 6.12 moles * 100 = 72.95%
I need help with this question
Which type of solute would have the greatest impact on a colligative property?
A. C6H12O6
B. NaCl
Where do animals obtain their chemical energy? I WILL MARK BRAINLEST HELP ASAP!!!
from plants only
from plants and animals
from animals only
directly from solar energy
Answer:
from plants and animals.
1 point
have specific requirements that need to be met in order for an
entrepreneur to be considered.
O Loans
O Investments
O None of the other answers
O Grants
What does chemistry mean?
Answer:
The definition of chemistry is a branch of science that deals with the form and properties of matter and substances or the interaction between individuals.
Determine the expected mass of the copper after 24 hours
The expected mass of copper element after 24 hours as per graph is 288 grams.
What is an element?It is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.In every 10 minutes 2 mg of copper is produced thus after 24 hours that is 1440 minutes copper amount will be 1440×2/10=288 mg.
Thus, the expected mass of copper element after 24 hours as per graph is 288 grams.
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Transcribe the following piece of DNA ........AAG-CCA-TGA-ACA
Answer:
TTC-GGT-ACT-TGT I could be wrong because A could eather be considered a U or a T, but u could also use UUC-GGU-ACU-UGU
someone pls help me!
Answer:
I think its A-When the car is cruising straight down a highway
HELP DUE IN 7 minutes TwT
Which product forms from the synthesis reaction between sodium (Na) and
sulfur (S)?
O A. Nasz
B. Nas
C. Na2S
O D. Na2S2
Answer:
Answer is C
Explanation:
the valency of sulphur is 2 ans sodium is 1
by crossing it forms NA2S
heeeeeeeeeeeeeeelpheeeeeeeeeeeeeeelp
Answer:
the mirror forms a virtual inlarged image
Explanation:
What is the standard cell notation of a galvanic cell made with aluminum and
nickel?
A. Ni(s) | Ni2+ || A13+(aq) | Al(s)
B. Al(s)| A13+(aq) || Ni2+(aq) | Ni(s)
C. Ni2+(aq) | Ni(s) || Al(s) | A13+(aq)
D. A13+(aq) | Al(s) || Ni(s) | Ni2+(aq)
D. A13+(aq) | Al(s) || Ni(s) | Ni2+(aq). The standard cell notation of a galvanic cell made with aluminum and nickel is A13+(aq) | Al(s) || Ni(s) | Ni2+(aq).
How do you represent galvanic cells in cell notation?The anode is on the left, and the cathode is on the right. The convention specifies that metals come first and then the metal ions present in the electrolyte represent the cell. And a vertical line is required to separate these two.
What does common cell notation entail?Voltaic or galvanic (spontaneous) cells are denoted by cell notations in shorthand. This special shorthand describes the anode, cathode, and electrode components as well as the reaction circumstances (pressure, temperature, concentration, etc.).
What materials make up a galvanic cell?A galvanic cell is made up of two distinct metals (electrodes), connected externally to complete a circuit and through a conducting liquid (an electrolyte).
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Help!!! Would give brainliest
Answer: Acids have a pH of less than 7 and generally form [tex]H^+[/tex] when dissolved in solution. [tex]H_2SO_4[/tex] is an example of acid.
Bases have a pH of more than 7 and generally form [tex]OH^-[/tex] when dissolved in solution. [tex]Ca(OH)_2[/tex] is an example of base.
Water is neutral and has a pH of exactly 7. Therefore in chemical equations it can act as acid or a base.
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution. pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pH=-\log [H^+][/tex]
pH values range from 1 to 14. Acids have a pH range from 1 to 6.9, water is neutral with pH of 7 and bases have pH ranging from 7.1 to 14.
Acids form hydrogen ions when dissolved in water and bases form hydroxide ions when dissolved in water. Water [tex]H_2O)[/tex] is amphoteric and thus can behave as an acid or a base.
[tex]H_2SO_4\rightarrow 2H^++SO_4^{2-}[/tex]
[tex]Ca(OH)_2\rightarrow Ca^{2+}+2OH^[/tex]
Which of the following is equal to one molecule of calcium atoms?
6.022x10^23 molecules of Ca
6.022x10^23 atoms of Ca
6.022x10^20 molecules of Ca
6.022x10^22 atoms of Ca
Answer:
https://download.cnet.com/1-Click-Answers/3000-2378_4-10060189.html
Explanation:
Answer:
6.022x10^23 atoms of Ca
Explanation:
For the balanced equation shown below, how many moles of N2 reacted, if 155 moles of NH3 are produced?
3H2 + N2 => 2NH3
Answer: 1 mole nitrogen produces 2 moles ammonia
How many moles you need for 155 mol ammonia?
155/2 moles
Explanation:
Did anyone do this worksheet (science)
PLZ HELP PPPLLLLLZZZZ HELP ITS OVER DUE PPPPPPPPPPPLLLLLLLLLLLLLLLLLLLLZZZZZZZZZZZ
do i have to know the chemical and physical properties of alloys? only chemistry students answer this.
Answer:
yes you do so you know how strong it is how maluble it's is so it can be customised to it's specific use
Answer:
alloy's properties are usually different from those of its component elements. Alloy constituents are usually measured by mass. Unlike pure metals, most alloys do not have a single melting point; rather, they have a melting range in which the substance is a mixture of solid and liquid.
physical properties of alloys:-Alloy steels have a wide range of special properties, such as hardness, toughness, corrosion resistance, magnetizability, and ductility. Nonferrous alloys, mainly copper–nickel, bronze, and aluminum alloys, are much used in coinage.
chemical properties of alloys:-Pure metals are useful but their applications are often limited to each individual metal's properties. Alloys allow metal mixtures that have increased resistance to oxidation, increased strength, conductivity, and melting point; Essentially any property can be manipulated by adjusting alloy concentrations.
dnt learn all thr properties.
these are the main properties..u can learn thse only. hope it will help u
Please Help I need to finish this by the end of the day!
Answer:
C
Explanation:
If I am not mistaken, due to the conservation of mass, whatever mass is on the side of the reactants should be the same for the product side.
This means
218.76g+53.96g = 272.72g
272.72g-266.66g = 6.06g
So the answer should be C
how many molecules are in 45.0 g of water
How many grams of ammonia would be produced from the reaction of 2.64 moles of hydrogen gas reacting with excess nitrogen?
Answer:
29.92g
Explanation:
tell me if my answer is wrong
What is needed to change a phase of matter?
The addition or subtraction of thermal energy. For example if you heat up an ice cube, it will melt to become water. If you heat it even more, it will evaporate.
Molar mass of Ag2SO4
Full work Pls
what is so unique about the ph scale 7?
Answer:
The pH scale 7 indicates neutral.
Explanation: