Answer:
5.95 moles
Explanation:
No of moles = given mass / molar mass
No of moles = 137/23
= 5.95 moles
what do you mean by calcination??
Answer:
Calcination refers to heating a solid to high temperatures in absence of air or oxygen, generally for the purpose of removing impurities or volatile substances.
Explanation:
hope it helps
Which substance has a melting point greater than room temperature
O A. argon
O B. oxygen
O
C. mercury
O D. aluminum
Aluminum is solid at room temperature and will, therefore, have a melting point that is above room temperature.
Melting pointThe room temperature is about 25 degrees Celsius.
Argon and oxygen are gases at room temperature.
Mercury is a liquid at room temperature.
Aluminum, on the other hand, is solid at room temperature. Hence, its melting point is definitely somewhere above room temperature.
More on melting points can be found here: https://brainly.com/question/25777663
An atom of which of the following has the least ability to attract electrons?
A. Silicon
B. Oxygen
C. Nitrogen
D. Bromine
Answer:
A. Silicon
Explanation:
The ability of an atom to attract electrons is known as electronegativity.
Electronegativity is the measure of the relative tendency with which the atoms of the element attract valence electrons in a chemical bond.
Across a period from left to right, the ability to attract electrons increases. Down a group, the ability decreases. Silicon is to the left most part and it will have the the least ability to attract electrons.A car traveled a distance of 30 km in 20 seconds (1/3 hour). What was the speed of the car?
Answer:
90.1km/hr
Explanation:
Given parameters:
Distance = 30km
Time = 20s = 0.33hr
Unknown :
Speed of the car = ?
Solution:
To solve this problem;
Speed = [tex]\frac{distance }{time}[/tex]
Now insert the parameters and solve;
Speed = [tex]\frac{30}{0.333}[/tex] = 90.1km/hr
“An electron is found only in specific energy levels around the nucleus of the atom.”
what is the evidence
Answer:
Hibhibihbhubhibhbuhbuhbhub
Explanation:
Why do scientist use the scientific method
Answer:
B
Explanation:
scientists always look for evidence
Answer:
Yea its B
Explanation: The person above me legit toke the answer out of my mouth
For fish to survive in your aquarium, you need to have a saturated solution of oxygen in the water. Suppose your aquarium holds 250L of water. How many grams of oxygen do you need to pump into the tank?
Answer:
The mass of oxygen needed to be pumped in the aquarium is 10 g
Explanation:
Here the value of the degree of solubility of oxygen in water is sought
The solubility of oxygen in fresh water is approximately 1.22 × 10⁻³ mol·dm⁻³ which is equivalent to approximately 40 mg/L
The volume of water the aquarium holds = 250 L
The mass of oxygen required = The solubility of oxygen in water × (The volume of water in the aquarium)
Therefore, the mass of oxygen needed to be pumped in the aquarium = 40 mg/L × 250 L = 10,000 mg
1,000 mg = 1 g
∴ 10,000 mg = 10 g
The mass of oxygen needed to be pumped in the aquarium = 10,000 mg = 10 g.
How many grams of carbon dioxide are produced by the combustion of 2.5 moles of ethane gas, C 2 H 6 at standard conditions?
2 C 2 H 6 (g)+7 O 2 (g) 4 CO 2 (g)+6 H 2 O (g)
Answer:
220g
Explanation:
The reaction equation is given as:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
Number of moles of ethane gas = 2.5moles
To find the mass of CO₂ produced, we need to know the number of moles of the compound produced;
2 mole of ethane gas produced 4 moles of CO₂
2.5 moles of ethane gas will produce [tex]\frac{2.5 x 4}{2}[/tex] = 5mole of CO₂
So;
Mass of CO₂ = number of moles x molar mass
Molar mass of CO₂ = 12 + 2(16) = 44g/mol
Mass of CO₂ = 5 x 44 = 220g
Help if you can please.
Answer:
I think it's Nuclear
There is a container with an unknown chemical. The container says that there is 1 mole
of the chemical inside, but the name of the chemical is unreadable. The label states
that the mass of the chemical inside is 28g and that the chemical is diatomic. After
pulling out your periodic table, you determine that the unknown chemical is...
The unknown chemical : Nitrogen gas : N₂
Further explanationGiven
1 mole of the unknown chemical
mass = 28 g
Required
The unknown chemical
Solution
A mole is a number of particles(atoms, molecules, ions) in a substance
This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles
Can be formulated :
mol = mass : molecular weight
Molecular weight(MW) = mass : mol
MW=28 g : 1 mol
MW= 28 g/mol
Because this compound is diatomic, it consists of 2 elements of the same type, so this element has a mass number:
28: 2 = 14
The element having the mass number 14 is N
Use the periodic table to calculate the percent composition of hydrogen in hexane.
Hexane's chemical formula is CH14.
es )))
A)
16.3%
B)
36.0%
C)
37.5%
D)
83.7%
Answer:
A)16.3% (Hexane's formula is C6H14)
How many valence electrons must Calcium lose when forming an ionic compound with Bromine?
Answer:
2
Explanation:
Describe the processes that have led to the formation of the soufriere hills volcano
Answer:
The Soufriere Hills volcano has formed where magma is actively seeping up from the mantle to the surface. Soufriere Hills volcano is part of an island chain that formed at the boundary where two oceanic plates converge. One plate subducts beneath the plate with the island chain, and the subducting plate melts in the mantle and creates magma that rises and fuels the Soufriere Hills volcano.
Explanation:
0.2 moles of aluminum has a mass of 5.4 g. what is The molar mass of aluminum
Answer:
Molar mass = 27 g/mol
Explanation:
Given data;
Number of moles of Al = 0.2 mol
Mass of Al = 5.4 g
Molar mass of Al = ?
Solution:
Formula:
Number of moles = mass/molar mass
By putting values,
0.2 mol = 5.4 g/ molar mass
Molar mass = 5.4 g/ 0.2 mol
Molar mass = 27 g/mol
yo someone wanna answer this?
Answer:
(1) Releases Energy
Explanation:
In the process called cellular respiration, energy is released from oxygen molecules.
Hope this helps! \ (•◡•) /
According to your investigation in part A, how do strong acids differ from weak acids? Select all the correct answers. Strong acids contain more A− than weak acids do. Strong acids contain more H3O+ than weak acids do. Strong acids contain more HA than weak acids do. Strong acids contain more OH− than weak acids do.
Answer:
Strong acids contain more A− than weak acids do.
Strong acids contain more H3O+ than weak acids do
Explanation:
When we talk about a strong acid, we are referring to any acid that is completely dissociated or ionized when it is in an aqueous solution.
It is very eager to lose a proton, H+ in solution according Arrhenius definition.
In aqueous solution, a strong acid ionizes as follows:
HA(aq) + H2O → H3O+(aq) + A−(aq)
Since, strong acids ionize completely in solution, strong acids contain a greater H3O+ and A− concentration than solutions of weak acids.
Answer:
A. Strong acids contain more A− than weak acids do.
B. Strong acids contain more H3O+ than weak acids do.
D. Strong acids contain more OH− than weak acids do.
Explanation:
Plato correct
Where would you expect detergent and
shampoos to be found?
Answer: the health isle next to tooth brushes maybe in a store? Why? Or in a closet? Umm
Explanation:
Answer:
The store.....is this like a trick question...? but yeah A store :))
Explanation:
Need help with this question please I’m really really going to appreciate it
Answer:
Alpha
Explanation:
^4 _2 He = alpha
^0 _-1 b = beta
^0 _0 y = gamma
The concept of energy can be calculated in multiple ways. Which units are used for energy? Check all that apply.
Answer:
NEWTONS,
Explanation:
Answer:
kilogram meters2/seconds2
joules
kilojoules
Explanation:
A company develops a new synthetic product and prepares to sell it to the public. Customers ask questions about how to properly dispose of the product. Which word is related to disposal? A. cost B. performance C. productivity D. profitability E. recyclability
Answer:
recyclability
Explanation:
recyclability
Explanation:
hope this helps
Describe four ways by which organisms reproduce asexually
Answer: thay can't make cells
Explanation:
What is the correct number of digits to express a measurement
Answer:
Examples of measured numbers: The diameter of a coin, such as 10.2 mm. The weight of an object, such as 8.887 grams. The length of a pen, such as 12 cm.
Explanation:
Answer:
It completely depends on what you are measuring, what instrument you are using, and the uncertainty associated with your measurement.
Explanation:
When expressing a measurement, there is always going to be a part that you know, and a part that you guess. They both make up known numbers collectively called significant figures (commonly shortened to "sig figs"). For instance, imagine you are measuring the length of a pencil. Let's say it is a typical ruler with divisions of 0.1 cm (picture for reference). You measure the pencil, and to your eyes it looks like it is about 9 cm and 5 small tick marks (so, 0.5 cm), so we'll call that 9.5 cm. Now, this is a known value, so you are certain that it is a least 9.5 cm. However, it may be true that there is one more decimal place that can be known. The general rule is that you want to add one more uncertain digit to the rightmost side of the number, and how many digits depends on the divisions of the instrument. Our ruler has divisions of 0.1 cm (the small tick marks), and so we will go one more place out, and add another digit. Now, let's say our eyes are pretty good, so let's say it's 9.5 cm, and then add that one uncertain digit, a 0 to the smallest division of 0.1, so, 0.10. The final measurement we record is 9.50 cm. Now, it may seem like we are simply guessing or even being unreasonable in our assessment of how long this pencil is. I can promise you that not knowing the actual measurement of this pencil will not make a spaceship crash because of a specification that was not the "right measurement". For those life-or-death measurements, much more precise measurement machines are used; this is just a pencil. Also, it would be unreasonable to say that it is 9.500000 cm or 9.500001 cm. We do not have that kind of certainty with this ruler, only divisions of 0.1 cm, so we can only estimate out to one more decimal place.
In short, find the smallest division of a ruler or whatever device (like a chemical beaker) you are using, and then add one uncertain digit to the end of that. If it's 0.1 cm, then add one digit to that. (example: 5.6 --> 5.63; 3 because that is what it looks like on the ruler). If it's 1 cm, then add an extra .1, so the measurement is 1.1 cm. And of course, it's not always cm you are using, that was just an example. Best of luck!
1.004 mol Arsenic is how many atoms?
Answer: [tex]6.047\times 10^{23}[/tex] atoms in 1.004 mol of arsenic
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the atoms, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given atoms}}{\text {avogadro's number}}[/tex]
[tex]1.004=\frac{x}{6.023\times 10^{23}}[/tex]
[tex]x=1.004\times 6.023\times 10^{23}=6.047\times 10^{23}[/tex]
Thus there are [tex]6.047\times 10^{23}[/tex] atoms in 1.004 mol of arsenic
A cube has a mass of 42 grams and a volume of 15 cubic centimeters. What is it’s density?
(Show your work or complete all problems for brainliest)
Answer:
2.8g/cm³
Explanation:
Given parameters:
Mass of cube = 42g
Volume of cube = 15cm³
Unknown:
Density of the cube = ?
Solution:
Density is defined as the mass per unit volume of a substance. It is mathematically expressed as:
Density = [tex]\frac{mass}{volume}[/tex]
So;
Density = [tex]\frac{42}{15}[/tex] = 2.8g/cm³
Wood burning has a ___________ (physical or chemical) property of _________ because... helpppp
Answer:
Wood burning would be a chemical change
Explanation:
You cannot undo the change, since the burn will be permanent.
(Hope this helps! If it does not try specifying)
concept of mole chemistry question
Answer:
How many molecules of water are there in 54 g of H2O H 2 O ? Solution. Molar Mass of H2O H 2 O = 2 + 16 = 18 g/moles. So ,number of moles of H2O H 2 O = Mass/Molar Mass = 54/18 =3 moles. Now 1 moles = 6.022×1023 6.022 × 10 23 molecule.
the bond between which two atoms is most polar
Answer:
bond
Explanation:
It is a polar bond because it is when two atoms bond
w 17. Which of the following is the atomic number of a halogen? A. O 10 B. 136 C. 17 D. 13
Answer:
C. 17
Explanation:
The question above is related to the "Periodic Table of Elements." The Halogen group is located on the right side of the table. It consists of six elements: Fluorine, Chlorine, Bromine, Iodine, Astatine and Tennessine.
The "atomic number" of an element refers to the number of protons that can be found in the element's nucleus. Among the halogens, "Chlorine" is the only one with an atomic number of 17. Halogens do not have an atomic number of 10, 136 and 13.
What increases the salinity of the ocean surface water, causing it to sink
downward?
Help
Answer:
Thermohaline Circulation
Explanation:
The process is known as “Thermohaline Circulation”. In the Earth’s polar regions ocean water gets very cold, forming sea ice. As a consequence the surrounding seawater gets saltier, because when sea ice forms, the salt is left behind. As the seawater gets saltier, its density increases, and it starts to sink.
A compound XO exists in nature. A scientist wanted to prepare the same compound in his lab based on the law of constant proportion but the formula of the compound that he prepared was found to be XO2. Which postulates of the law of constant proportion did he violate?
Answer:
The postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
Explanation:
The law of constant composition (or definite proportion) states that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
This law implies that irrespective of the source of the sample of the compound or the method by which the sample was prepared, as long as the sample is pure, the elements present in the compound are always combined in a specific ratio by mass. For example, water has the molecular formula H₂O. Irrespective of the water source, for example, tap-water, lake, stream, river or rainfall, each pure sample of water will have the constant composition of 2 atoms of hydrogen to one atom of oxygen.
The given compound exists as XO in nature. Therefore, irrespective of the source or method of preparation, every sample of this compound should have the formula XO. Since the compound prepared by the scientist was XO₂, therefore, the postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass was violated by the scientist. The scientist must have prepared a different compound of the elemental compositions.