Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
We have
[tex]n = \frac{8.3 \times {10}^{12} }{6.02 \times {10}^{23} } \\ \\ \\ \\ \: \: \: \: \: \: \: = 1.379 \times {10}^{ - 11} \: \: \: \: moles[/tex]
Hope this helps you
what are some examples of long term environmental changes???
Answer: A long-term environmental change is... ice age, deforestation, urbanization, Earth's orbit, Sun's intensity, global Warming, radioactive waste/pollution. Extinction of species could happen to anyone of the food webs in a long term change.
Explanation:
What is a jet stream. in your own words but be more detailed about what you say.
(don't send a link or file)
what does molecule mean?
a.) A pure substance, only one type of atom
b.) Two or more atoms held together by chemical bonds
c.)Composed of two or more separate elements
d.)The smallest part of matter still retaining chemical properties
A pure substance, only one type of atom
Answer:
(a) a pure substance, only one type of atom
True or False: Molecular formula gives you the smallest whole number ratio of elements in a compound. *
Answer:true
Explanation:The molecular formula indicates the exact number of atoms in the molecule. The empirical formula expresses the smallest whole number ratio of the atoms in the element.
Calculate the molar solubility of aluminum hydroxide (AlOH)3) in a 0.027M solution of aluminum nitrate (Al(NO3)3). The Ksp of AlOH)3 is 2.0x10-32.
Answer:
s = 5.22x10⁻⁹ M
Explanation:
Let's write the equilibrium reaction for this compound:
Al(OH)₃ <-------> Al³⁺ + 3OH⁻ Ksp = 2x10⁻³²
To get the solubility, we need to write the equilibrium expression:
Ksp = [Al³⁺] [OH⁻]³
Al(OH)₃ does not contribute to the equilibrium expression, because is a solid compound. Now, according to this, we have the following:
Al(OH)₃ <-------> Al³⁺ + 3OH⁻
I. 0 0
E. s 3s
Replacing into the Ksp expression:
2x10⁻³² = (s) (3s)³
2x10⁻³² = s * 27s³
2x10⁻³² = 27s⁴
s = ⁴√2x10⁻³² / 27
s = 5.22x10⁻⁹ MThis would be the solubility of the compound.
Hope this helps
A car engine produces 604 kJ of mechanical energy from fuel capable of producing 2416 kJ of energy. The efficiency of the engine is
A car engine produces 604 kJ of mechanical energy from fuel capable of producing 2416 kJ of energy, then efficiency of the engine is 25%.
How do we calculate efficiency?We can calculate the efficiency by using the below equation as:
Efficiency = (Actual production / Theoretical production) × 100%
Given that,
Actual production = 604 kJ
Theoretical production = 2,416 kJ
On putting values in given equation, we get
Efficiency = (604/2,416) × 100% = 25%
Hence efficiency of the engine is 25%.
To know more about efficiency, visit the below link:
https://brainly.com/question/15418098
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If 200 mL of a gas at 27 °C is cooled to -33 °C at a constant pressure, the volume will be
Answer:
V2 = 159.48 mL
Explanation:
Given the following data;
Initial volume = 200 mL
Initial temperature = 28°C
Final temperature = -33°C
To find the final volume, V2, we would use Charles law;
First of all, we would convert the temperature in Celsius to Kelvin.
Mathematically, it is given by the formula;
Kelvin = 273 + C
Substituting into the equation, we have;
Initial temperature, T1:
Kelvin = 273 + 28
Kelvin = 301K
Initial temperature, T1:
Kelvin = 273 - 33
Kelvin = 240K
To find new volume V2, we would use Charles' law.
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles is given by;
[tex] VT = K[/tex]
[tex] \frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]
Where;
V1 and V2 represents the initial and final volumes respectively.
T1 and T2 represents the initial and final temperatures respectively.
[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]
Making V2 as the subject formula, we have;
[tex] V_{2}= \frac{V1}{T1} * T_{2}[/tex]
[tex] V_{2}= \frac{200}{301} * 240[/tex]
[tex] V_{2}= 0.6645 * 240 [/tex]
V2 = 159.48 mL
What is the name of this hydrocarbon?
Answer:
2,3-dimetylpentane
Explanation:
.....................
Question: How do we read chemical formulas?
Any molecule can be represented by a formula that lists all the atoms in that molecule. Each element is represented by its atomic symbol in the Periodic Table – e.g. H for hydrogen, Ca for calcium. If more than one atom of a particular element is present, then it’s indicated by a number in subscript after the atomic symbol — for example, H2O means there are 2 atoms of hydrogen and one of oxygen.
If there is more than one of whole groups of atoms, then that’s shown with a bracket around them. For example, calcium hydroxide has one calcium (Ca) for every two hydroxides (OH), so is written as Ca(OH)2.
If a charge is present, it’s indicated in superscript, with a sign (+/-) and a number if more than one charge is present. For example, calcium ions have two positive charges so are written Ca2+.
Sometimes a formula can be written in a way that gives an indication of the structure. A chemical equation shows a reaction taking place. On the left-hand side are the reactants, the molecules that take part in the reaction. On the right-hand side are the products, the molecules that are created in the reaction. Each side must contain the same number of each kind of atom. An arrow between them indicates the direction the reaction is expected to occur:
Ca + Cl2 → CaCl2
Calcium + chlorine → Calcium chloride
If there are two or more of any molecules, that’s indicated with a number in front of the molecule:
CH4 + 2O2 → CO2 + 2H2O
One methane molecule + two oxygen molecules → one carbon dioxide molecule and two water molecules
An equation may sometimes specify which phase each molecule is in – whether it’s solid, liquid, or gas, or if it’s dissolved. This is written in brackets after the molecule – (s) for solid, (l) for liquid, (g) for gas, and (aq) for ‘aqueous’, meaning dissolved in water. For example, solid calcium carbonate reacts with carbonic acid in water to form calcium bicarbonate, which is much more soluble so becomes dissolved in water:
CaCO3 (s) + H2CO3 (aq) → Ca(HCO3)2 (aq)
Solid calcium carbonate + dissolved carbonic acid → dissolved calcium bicarbonate
All chemical reactions can actually proceed in either direction. Most of the time, one direction is expected to take place more strongly, so the arrow is written in that direction. However, many common reactions happen in both directions simultaneously, creating an equilibrium where the reactions are taking place but there is no net change in concentration from one side to the other. This is indicated with the symbol ⇌.
For example, carbonic acid in water is continually breaking down into bicarbonate and hydrogen ions – but the ions are also continually joining back together.
H2CO3 ⇌ HCO3– + H+
Carbonic acid ⇌ bicarbonate + hydrogen ions
If 10.5 g of iron, at 25°C, absorbs 128 J of heat, what will be the final temperature of metal? (The specific heat of iron is 0.449 J g-1 °C-1)
Answer:
27.5°C = Final Temperature of the metal
Explanation:
The change in temperature using the specific heat of a material could be obtained using the formula:
Q = m*S*ΔT
Where Q is heat absorbed in Joules = 128J in the problem
m is the mass of the substance = 10.5g
S is Specific Heat of the substance = 0.449J/g°C for Iron
ΔT is change in temperature = Final T - Initial T
Replacing:
128J = 10.5g*0.449J/g°C*ΔT
2.5°C = ΔT
2.5°C = Final T - 25°C
27.5°C = Final Temperature of the metal
Hydrologers study the availability of fresh water on the planet.
Answer:
Hydrologists study how water interacts with the earth's crust. For example, they may study how rainfall and snowfall cause erosion, create caves, percolate through soil and rock to become groundwater, or eventually reach the sea.Hydrologists strive to improve water quality and increase our access to water so that we can continue to make use of it in all the ways that are necessary to our lives. A hydrologist measures the stream flow in a tributary to the Coeur d'Alene River. layers of gases surrounding a planet or other celestial body
explain what conservation of mass is and how to calculate it
A compound contains 1.2 g of carbon, 3.2 g of oxygen and 0.2g of hydrogen. Find the formula of the compound
Answer:
The empirical formula of the compound is [tex]C_{0.504}HO_{1.008}[/tex].
Explanation:
We need to determine the empirical formula in its simplest form, where hydrogen ([tex]H[/tex]) is scaled up to a mole, since it has the molar mass, and both carbon ([tex]C[/tex]) and oxygen ([tex]O[/tex]) are also scaled up in the same magnitude. The empirical formula is of the form:
[tex]C_{x}HO_{y}[/tex]
Where [tex]x[/tex], [tex]y[/tex] are the number of moles of the carbon and oxygen, respectively.
The scale factor ([tex]r[/tex]), no unit, is calculated by the following formula:
[tex]r = \frac{M_{H}}{m_{H}}[/tex] (1)
Where:
[tex]m_{H}[/tex] - Mass of hydrogen, in grams.
[tex]M_{H}[/tex] - Molar mass of hydrogen, in grams per mole.
If we know that [tex]M_{H} = 1.008\,\frac{g}{mol}[/tex] and [tex]m_{H} = 0.2\,g[/tex], then the scale factor is:
[tex]r = \frac{1.008}{0.2}[/tex]
[tex]r = 5.04[/tex]
The molar masses of carbon ([tex]M_{C}[/tex]) and oxygen ([tex]M_{O}[/tex]) are [tex]12.011\,\frac{g}{mol}[/tex] and [tex]15.999\,\frac{g}{mol}[/tex], then, the respective numbers of moles are: ([tex]r = 5.04[/tex], [tex]m_{C} = 1.2\,g[/tex], [tex]m_{O} = 3.2\,g[/tex])
Carbon
[tex]n_{C} = \frac{r\cdot m_{C}}{M_{C}}[/tex] (2)
[tex]n_{C} = \frac{(5.04)\cdot (1.2\,g)}{12.011\,\frac{g}{mol} }[/tex]
[tex]n_{C} = 0.504\,moles[/tex]
Oxygen
[tex]n_{O} = \frac{r\cdot m_{O}}{M_{O}}[/tex] (3)
[tex]n_{O} = \frac{(5.04)\cdot (3.2\,g)}{15.999\,\frac{g}{mol} }[/tex]
[tex]n_{O} = 1.008\,moles[/tex]
Hence, the empirical formula of the compound is [tex]C_{0.504}HO_{1.008}[/tex].
When workers stop working entirely, it is called a(n)
Answer here
SUB
Answer:
Explanation:
When workers stop working entirely, it is called either a strike or retirement, depending on the circumstances under which it is done. A strike is a mass refusal of employees to work, because they are not satisfied.
Retirement on the other hand happens when the employee reaches certain age, after which he/she can leave the job and get a pension,.
what is chemical bonding
Answer:
In simple terms it is when two chemicals bond with each other
Explanation:
For more detailed explanation here's your answer:-
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. It has Electrostatic force between the two molecules. It can be either positive or negative ionswhat are the three method used to treat water ?
Answer:
The three methods used to treat water are
Filtration SedimentationDistillationExplanation:
These methods used include physical processes, biological processes such as slow sand filters or biologically active carbon; chemical processes such as flocculation and chlorination; and the use of electromagnetic radiation such as ultraviolet light.
Why are scientists using acoustic surveys to learn about rainforest diversity
Answer:
Acoustic survey data can help inform scientists about the locations of the rainforest with the highest biodiversity. ... By working with these companies, The Nature Conservancy can help inform them of where they might try to create wildlife corridors or connected habitats on their lands
Two firefighters are trying to break through a door. One firefighter is heavy, and the other is light. If they run at the same speed, which one is more likely to break through?
Answer:
the heavy one
Explanation:
the heavy one because heavy things and break things and the light one can't
A 3.20-mol sample of gas occupies a volume of 350. mL at 300.0 K. Determine the
pressure of the gas.
Answer:
[tex]P \approx 225atm[/tex]
Explanation:
From the question we are told that:
Moles of sample n=3.20_mol
Volume V=350mL
Temperature T=300k
Generally the equation for ideal gas is mathematically given by
[tex]PV=nRT[/tex]
[tex]P=\frac{nRT}{V}[/tex]
[tex]P=\frac{3.20*0.08206*300}{350*10^{-3}}[/tex]
[tex]P=225.079atm[/tex]
[tex]P \approx 225atm[/tex]
an organism that a parasite lives in or on is a
A. prey
B. host
C. consumer
D. prey
For the combustion of acetaldehyde, CH2CHO, there is 42L at STP and 79g of Oz. How much water is produced?
____N2 + ____H2 ____NH3
Answer:
N2 + 3H2 + 2NH3
Explanation:
I'm assuming you're balancing the chemical equation
[tex]nitrogen \: reacts \: with \: hydrogen.[/tex]
N2 + 3H2 → 2NH3.
Explanation:-
L.H.S.
N = 2, H = 3×2 = 6.
R.H.S.
N = 2, H = 3×2 = 6.
why should Asus be stores only in the glass containers please answer this
Answer:
Do you mean acids?
Due to chemical reaction
Explanation:
Acids are only stored in glass containers because glass containers rarely react with any substance.They dont react with acids and prevent chemical reaction so the acids can be kept. If acids were kept in metal containers it would react .
Which of the following represents alpha decay?
Answer: b
Explanation: alpha decay or particle consist of two protons and two neutrons hence it is a helium nucleus.
An alpha particle [tex]\binom {4} {2}[/tex]He is produced in alpha decay reactions, while the parent nucleus' atomic number and mass number drop by 2 and 4 correspondingly.
Alpha decay:Alpha decay is a nuclear process whereby an unstable nuclear transforms into a different element by ejecting particles composed of two protons and two neutrons. The alpha particle also referred to as a helium nucleus, is the expelled unit of matter. Alpha particles have large masses and electrostatic attraction.An atomic number decreases by 2 and the atomic weight drops by 4 when a radioactive nucleus disintegrates by emitting [tex]\bold{\alpha}[/tex] particle.Therefore, the final answer is "Option B".
Find out more about the alpha decay here:
brainly.com/question/14081292
how to balance _h2s+ _o2 = _h2o+ _s
Answer:
2H₂S + 1O₂ → 2H₂O + 2S
Explanation:
SOLUTION :-
Balance it by using 'hit & trial' method , and you'll get the answer :-
2H₂S + 1O₂ → 2H₂O + 2S
VERIFICATION :-
In reactant side of equation :-
Number of atoms in H = 2×2 = 4Number of atoms in S = 2×1 = 2Number of atoms in O = 1×2 = 2In product side of equation :-
Number of atoms in H = 2×2 = 4Number of atoms in O = 2×1 = 2Number of atoms in S = 2×1 = 2Number of atoms of each element is equal in both reactant & product side of equation. Hence , the equation is balanced.
20. Which of the following is the correct name for N205?
O nitrate oxide
O dinitrogen pentoxide
O nitrous oxide
O nitrogen dioxide
Answer:
B!
Explanation:
Di stnds for 2 (N2)
pent = 5 (05)
The valences of metal x,y and z are 1,2 and 3 respectively. What are the formulae of their;a) hydroxides, b) sulphates, c) hydrogen, d) carbonates, e) nitrates, f) phosphates
Answer:
See answer below
Explanation:
AS we know that the valence for those metals X, Y, and Z are 1, 2 and 3, we can determine the formula of each compound.
1. Hydroxides.
An hydroxide is formed when an oxyde of a metal reacts with water. When this happens, the general molecular formula is:
Meₐ(OH)ₙ
Where:
a: valence or charge of the hydroxide (Which is -1)
n: valence of the metal.
Following this, the formula for X, Y and Z would be:
XOH
Y(OH)₂
Z(OH)₃
2. Sulphates
Sulphates follow a similar rule of hydroxide in the general molecular formula, but instead of having a charge of -1, it has a charge of -2 so:
Mₐ(SO₄)ₙ
So, following the rule:
X₂SO₄
Y₂(SO₄)₂ ------> YSO₄
Z₂(SO₄)₃
3. Hydrogens
Following the same rule as the previous, hydrogens works with a charge of -1, so:
MₐHₙ
Then:
XH
YH₂
ZH₃
4. Carbonates.
This follows the same rule as sulphates, with the same charge so:
Mₐ(CO₃)ₙ
Then:
X₂CO₃
YCO₃
Z₂(CO₃)₃
5. Nitrates
Follow the same rule as the hydroxides, with the same charge of -1.
Mₐ(NO₃)ₙ
Then:
XNO₃
Y(NO₃)₂
Z(NO₃)₂
6. Phosphates
In the case of phosphates, these have a charge of -3 so:
Mₐ(PO₄)ₙ
Then:
X₃PO₄
Y₃(PO₄)₂
Z₃(PO₄)₃ ----> ZPO₄
Hope this helps
What is 90 kPa when converted to atm?
A. 0.5 atm
B. 0.88 atm
C. 1 atm
D. 1.5 atm
Can you show the work
When you mix water and salt you get a.
What product is formed when sodium and chlorine undergo a synthesis reaction? sodium chlorite
sodium chlorate
sodium and chloride
sodium chloride