Answer:
KBr final solution:
V = 250mL --> 0.25L
Concentration/Molarity = 1.5 mol/L
To find the amount of moles of KBr here, just multiply the volume by the concentration (0.25 x 1.5 = 0.375 mol)
So the amount of moles for KBr is 0.375 mol. Now we know that the mass divided by the molar mass (the atomic mass values of K and Br in the periodic table added together) would give us the amount of moles aswell.
n = moles
m = mass
M = molar mass
n = m/M
so if we rearrange this equation to find mass, we would get:
m = n x M
Molar mass for KBr: (39.09) of K + (79.90) of Br = 118.99
m = 0.375 mol x 118.99
m = 44.62g
Therefore 44.62g of KBr is needed to make 250mL of a 1.5 M KBr solution.
what is electromagnetisim
Answer:
science of electromagnetic fields
Explanation:
(winks and runs off)
How many molecules are in 21.5G of water
Answer:
There are 6.022×1023 molecules in a mole. There are 18.01528 grams of water per mole of water. in 1g water
Explanation:
please Mark my answer in brainlist
How are the forces acting on an airplanes flying similar to the forces acting on a boat moving through water?
Answer: The four forces acting on an aircraft in straight-and-level, unaccelerated flight are thrust, drag, lift, and weight.
Explanation:
20. At STP, an element that is a solid and a
good conductor of heat and electricity
could have an electron configuration of
(1) 2-7
(2) 2-8-8
(3) 2-8-5
(4) 2-8-18-2
20
Answer:
4
Explanation:
Zinc
What is a single layer of graphite called
Asking for GCSE Chemistry
Answer:
GRAPHENE is a single layer of graphite
Explanation:
each carbon atom bonded to 3 other carbon atoms forming a hexagonal lattice
What do you already know about throwing a curveball?
Answer: You have to have good mechanics as well as the curve with velocity and speed.
The MLB Pitchers you see can be an example.
Commentators yelling Nasty Curveball, Strikeout!!
How much aluminum can be extracted from 3.5 metric tons of bauxite ore which is 70% aluminum oxide?
Answer:
A) 17.5%
B) 1) 2135 kg
2) 375 kg
C) 91.8
Explanation:
Part (A):
1 tonne= 1000 kg= 100%
Aluminium oxide= 825 kg= 82.5%
Iron (lll) oxide= 100 kg= 10%
Sand= 85 kg= 7.5%
That makes total of 100%
So, the percentage of impurities= Iron (lll) oxide + Sand
=> 10 + 7.5= 17.5%
Part (B):
(1) 1 tonne= 427 kg
Multiplying both sides by 5
=> 5 tonne= 427 * 5
=> 5 tonne = 2135 kg
(2) 1 tonne contains 75 kg sand as impurity
=> 1 tonne= 75 kg
Multiplying both sides by 5
=> 5 tonnes = 75 * 5
=> 5 tonnes = 375 kg
Part (C):
If all of the iron oxide was removed, then only aluminium and sand are left.
Aluminium = 825 kg
Sand= 74 kg
Total of them makes it:
=> 825 + 74 = 899
So,
% age of Aluminium= 825/899 * 100
% age of Aluminium= 0.918 * 100%
% age of Aluminium= 91.8%
What are the consequences of increased nitrogen and phosphorus into water systems? (Site 3).
Answer:
But when there is too much phosphorus and nitrogen into water systems, it can speed up the process of eutrophication ( increase in the concentration of minerals and nutrients, which enhances the growth of algae, which causes algal blooms). Due to this, dissolved oxygen level is declined as not enough light penetrates in the water body.
Explanation:
What are the four groups of carbon compounds found in living things?
what is the ratio of oxygen to iron in iron oxide?
Answer:0.2865
Explanation:
Which does ionic bonding involve?
The diagram represents an atom of an element key
e = electron = 4
n = neutron = 5
p = proton = 4
Which symbol gives this information?
What are all the chemical reaction takes place if Conc HNO3 acids leaks in seawater and at what dilution ratio it gets neutralized?
Answer:
Chemical formula: HNO₃
Melting point: −42 °C (−44 °F; 231 K)
Molar mass: 63.012 g·mol−1
Solubility in water: Miscible
Explanation:
When Conc HNO3 acid leaks into seawater presumed to be largely consisting of Sodium Chloride and other dissolved salts, I won't consider it as a chemical reaction rather it is a Physical Change. I presume this activity as a mixture when the acid been the solute becomes a contaminants
a compound is a substance composed of two or more elements in a fixed ratio. true or false?
Answer:
its true..plz mark me brainliest
Explanation:
there are two questions
1. what is the energy associated with electromagnetic radiation of 6.34 x 10^15 hertz
2. What is the frequency of one of the bands of the sodium emission spectrum that has a wavelength of 585 nanometers?
1. The energy associated with an electromagnetic radiation of [tex]6.34 \times 10^{15} \;Hertz[/tex] is equal to [tex]4.2 \times 10^{-18}\;Joules[/tex].
2. The frequency of one of the bands of the sodium emission spectrum is [tex]5.13 \times 10^{14}\;Hertz[/tex]
Given the following data:
Frequency = [tex]6.34 \times 10^{15} \;Hertz[/tex]Wavelength = 585 nm to m = [tex]5.85 \times 10^{-7}\;meters[/tex]Scientific data:
Speed of light = [tex]3 \times 10^8\;meters[/tex]Planck constant = [tex]6.626 \times 10^{-34}\;J.s[/tex]1. To determine the energy associated with an electromagnetic radiation of [tex]6.34 \times 10^{15} \;Hertz[/tex], we would apply Einstein's equation for photon energy:
Mathematically, Einstein's equation for photon energy is given by the formula:
[tex]E =hf[/tex]
Where:
E is the energy.h is Planck constant.f is photon frequency.Substituting the given parameters into the formula, we have;
[tex]E = 6.626 \times 10^{-34}\times 6.34 \times 10^{15} \\\\E = 4.2 \times 10^{-18}\;Joules[/tex]
2. To determine the frequency of one of the bands of the sodium emission spectrum:
Mathematically, the frequency of a wave is given by the formula:
[tex]Frequency = \frac{Speed}{wavelength} \\\\Frequency = \frac{3 \times 10^8}{5.85 \times 10^{-7}} \\\\Frequency =5.13 \times 10^{14}\;Hertz[/tex]
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a positively or negatively charged particle is called:
Answer:
A positively or negatively charged particle is called an ion.
Explanation:
Ions form when they lose or gain electrons in order to become stable by filling their octet. When an element lose an electron(s), it becomes positively charged and occpanies the symbol (+). When an element gains an electron(s), it becomes negatively charged and occpanies the symbol (-).
most elements are (1) metals (2)nonmetals (3)gases (4)made in labs
To form a charge of +2 an atom must________electrons.
To form -3 it must ________ electrons.
Multiple choice:
1) gain2 ;lose 3
2) gain3: lose2
3) lose2;gain3
4) lose3; gain2
Answer:
Explanation:
3
How did the industrial revolution contribute to global climate change
Answer:humans have put ridiculous amounts of carbon dioxide into the atmosphereThese events are linked to the mass burning of fossil fuels to meet an increase in human demand
So the answer is True
Explanation:
Burning fossil fuels, such as coal and oil, has increased the quantity of greenhouse gases in our atmosphere since the Industrial Revolution began around 1750.
What is atmosphere?Atmosphere is defined as a layer of gas that surrounds a planet and is kept there by the gravitational pull of the planetary body. The atmosphere of Earth includes five primary layers and a number of minor ones.
Industrial revolution is defined as the transition of an economy based on agriculture and handicrafts to one driven by industry and machine production. The causes of industrial revolution are the advent of capitalism, European imperialism, efforts to mine coal, and the effects of the Agricultural Revolution are some of the factors that historians have recognized as contributing to the Industrial Revolution.
Thus, burning fossil fuels, such as coal and oil, has increased the quantity of greenhouse gases in our atmosphere since the Industrial Revolution began around 1750.
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A 23.6 g sample of an unknown gas occupies a volume of 12.0 L at standard temperature and pressure. What is the molecular mass (molar mass) of this gas?
The molecular mass (molar mass) of this gas is equal to 44.08 g/mol.
Given the following data:
Mass = 23.6 gramsVolume = 12.0 LitersStandard temperature = 273 KStandard pressure = 1 atm.To calculate the molecular mass (molar mass) of this gas, we would use the ideal gas law equation;
[tex]PV=\frac{MRT}{MM}[/tex]
Where;
P is the pressure.V is the volume.M is the mass of substance.MM is the molar mass of a substance.R is the ideal gas constant.T is the temperature.Making MM the subject of formula, we have:
[tex]MM = \frac{MRT}{PV} \\\\MM = \frac{23.6\times 0.0821 \times 273}{1 \times 12}\\\\MM = \frac{528.95}{12}[/tex]
Molar mass, MM = 44.08 g/mol.
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how many electrons can there be in the 2p subshell?
Answer:
6 possible electron can fit into the 2p subshell
Which of the following terms is a chemical substance made of a single type of atom that cannot be broken down into a simpler substance?
A- nucleus
B- molecule
C- Compound
D- Element
The equation for a base solution is B + H2O = BH+ + OH- The strength of the base in a solution is increased. How
will the number of particles change? (1 point)
O The number of B molecules will increase, and the number of OH ions will decrease.
The number of BH molecules will increase, and the number of water molecules will decrease.
The number of OH-ions will increase, and the number of BH molecules will decrease.
O The number of B molecules will increase, and the number of water molecules will decrease.
Answer:The number of BH+ Molecules will increase , and the number of water molecules will decrease
Explanation:
The number of OH- ions will increase, and the number of BH molecules will decrease.
Option (3) is correct.
In the given base solution equation, B + H₂O = BH⁺ + OH⁻, when the strength of the base is increased, more B molecules will react with water to form BH⁺ and OH⁻ ions. This happens because a stronger base donates more OH⁻ ions into the solution, increasing its concentration.
As the base becomes stronger, more B molecules will participate in the reaction, forming fewer BH⁺ molecules since they are being converted to BH⁺ ions. Simultaneously, the increased concentration of OH⁻ ions means that the number of OH⁻ ions in the solution will increase.
Overall, the change in the number of particles can be summarized as follows:
The number of BH molecules will decrease.
The number of OH⁻ ions will increase.
This change reflects the increase in the concentration of OH⁻ ions, which is a characteristic of a stronger base solution.
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8)
What mass of hydrogen is needed to react with 32 g of copper oxide?
CuO + H2 → Cu + H2O
Answer:
1.22gram of hydrogen is needed to react
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 0.40 g mass of hydrogen is needed to react with 32 g of copper oxide.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
CuO + H[tex]_2[/tex]→ Cu + H[tex]_2[/tex]O
mole of copper oxide= 32 /79.54
=0.40 mole
The mole ratio between copper oxide and hydrogen is 1:1
mole of hydrogen= 0.40 mole
mass of hydrogen = 0.40 mole×1g/mol
= 0.40 g
Therefore, 0.40 g mass of hydrogen is needed to react with 32 g of copper oxide.
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Chlorine and oxygen form many different compounds, including CIO, and Cl2O3. How do the names of these compounds differentiate one chlorine oxide from another?
Answer:
We can mix two compounds and create a third that bears little resemblance to its parents. For instance, by mixing two parts of hydrogen gas with one of oxygen - liquid water is formed. We should not be misled by the fact that chlorine and chlorine dioxide share a word in common. The chemistries of the two compounds are completely different.
Chlorine and chlorine dioxide are both oxidizing agents (electron receivers). However, chlorine has the capacity to take in two electrons, whereas chlorine dioxide can absorb five. This means that mole for mole, ClO2 is 2.6 times more effective than chlorine.
If equal, if not greater importance is the fact that chlorine dioxide will not react with many organic compounds, and as a result, ClO2 does not produce environmentally dangerous chlorinated organics. For example; aromatic compounds have carbon atoms arranged in rings and they may have other atoms, such as chlorine, attached to these rings, to form a chlorinated aromatic - a highly toxic compound that persists in the environment long after it is produced.
Chlorine dioxide's behaviour as an oxidizing agent is quite dissimilar. Like ozone, the predominant oxidation reaction mechanism for chlorine dioxide proceeds through a process known as free radical electrophilic (i.e. electron-attracting) abstraction rather than by oxidative substitution or addition (as in chlorinating agents such as chlorine or hypochlorite). This means that chlorinated organic compounds such as THMs and HAAs are not produced as a result of disinfection using chlorine dioxide
Hope this helps, have a nice day! :D
The way that the names of these compounds show that the Chlorine oxides are different is by making reference to the number of individual molecules in the compound.
How are the chlorine oxides differentiated?The number of chlorine and oxygen molecules in each compound are used to name the compounds which ensures that they are differentiated.
ClO₂ is called "Chlorine Dioxide" which shows that there are two Oxygen atoms.
Cl₂O₃ is called "Dichlorine Trioxide" which shows that there are two Chlorine molecules and 3 Oxygen molecules.
Find out more on Chlorine oxides at https://brainly.com/question/25937152.
what is neutralisation??
Answer:
Acid + Base -------> Salt + Water
Explanation:
The reaction between an acid and bases is called a neutralization reaction. The result of the reaction is salt and water. For example, when hydrochloric acid(acid) and sodium hydroxide(base) react they form sodium chloride(salt) and water. Also, heat is evolved.
Example:
HCl + NaOH ----------> NaCl + H2O
HCl is hydrochloric acid.
NaOH is sodium hydroxide which is a base.
NaCl is sodium chloride which is a salt.
H2O is water.
Element Dy has 3 known isotopes. If.2% of the sample has a mass of 160
amu, .06% has a mass of 160.9 amu and the remaining has a mass 162
amu, what is the predicted mass of Dy?
Answer:
this girl in my class is getting a dog
Explanation:
but shes annoying so im hit her
what causes chemical change in the stomach?
Answer:
The chemical change in the stomach, known as food digestion, is from the enzymes in the liver and stomach where they break down food molecules into even smaller molecules in order for them to be digested more easily.
a) C8H18
Name the organic compound
Answer:
Explanation:
Octane
Octane is a straight chain alkane composed of 8 carbon atoms.
PLEASE HELP CHEMISTRY QUESTION
When two solutions are mixed in a beaker, a reaction occurs, and the temperature drop is the reaction of……..
A) exothermic and -ve enthalpy
B) endothermic and -ve enthalpy
C) exothermic and +ve enthalpy
D) endothermic and +ve enthalpy
Answer:
B
Explanation:
the reaction is endothermic because of the temperature drop and the enthralpy is negative because its an endothermic reaction.
I did some research so I believe this to be correct but if its no I'm sorry