True or false stars will eventually burn out causing the universe become cold and dark
A sample of an unknown gas has a mass of 0.116 g. It occupies a volume of 25.0 mL at a temperature of 127°C and has a pressure of 155.3 kPa. Calculate the molar mass of the gas.
Answer:
The molar mass of the gas is 99.4 g/mol
Explanation:
Ideal gas law PV=nRT. P=155.3 T=127+273= 400K V=25.0 Gas constant=8.314 Now substiture the values into the equation n=PV/RT
n= (155.5kPa x 25.0mL x 1l/1000mL)/ 8.312l*KPa/mol*K x 400K
n= 0.001167 mol
Molar mass= Mass/ Number of moles
= 0.116g /0.001167 mol
= 99.4 g/mol
A fluid flowing in a pipe has 1.05 in diameter. If the fluid has density, viscosity and
volumetric flow rate are 62.3 , 1.2 cP and 35 gpm respectively. Calculate: 3
a) The velocity.
b) Reynolds number ()
[2]- Find the following
a) Drive an expression to find a pressure of methane gas at point B b) If the temperature of methane is 100 F, Calculate pressure of
methane gas at point B.
c) Calculate pressure of oil at point C.
PA = 1, 000 psig
[3]- If the water is pumped down one well and the displaced oil which flows up through well exit (see the fig below), drive an expression to find a pressure of inlet water Pw needed to displace oil when the water/oil interfacial tension σ is applied.
Velocity is a vector quantity that describes the rate and direction of an object's motion.
a) The velocity of the fluid:
V = 35 gpm / (π * (1.05 in)^2 / 4) = 7.09 ft/s
b) Reynolds number:
Re = (62.3 lbm/ft^3 * 7.09 ft/s * 1.05 in) / (1.2 cP) = 4,211.9
[2]- a) Expression to find pressure of methane gas at point B:
PB = PA + rgh
b) Pressure of methane gas at point B:
PB = 1,000 psig + (0.072 lbm/ft^3 * 32.2 ft * 0.0689 psia/ft) = 1,233.5 psig
c) Pressure of oil at point C:
PC = PB - 0.433 psia/ft * 32.2 ft = 1,093.3 psig
[3]- Expression to find pressure of inlet water Pw needed to displace oil:
Pw = PC + (σ / r) * (h2 - h1)
Pw = 1,093.3 psig + (σ / 0.072 lbm/ft^3) * (32.2 ft - 0 ft) = 1,093.3 psig + (σ / 0.072 lbm/ft^3) * 32.2 ft.
What is velocity?
Velocity is a vector quantity that describes the rate and direction of an object's motion. It is commonly represented by the symbol 'v' and is measured in meters per second (m/s). Velocity includes both the speed and the direction of the object. For example, if an object is moving north at 10 m/s, its velocity would be 10 m/s north. Velocity can also be determined by taking the derivative of the position function with respect to time.
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Please help. Will give brainliest
Answer:
the answer to this is 71.0 grams of chlorine
James decided to do an experiment with a can of soda. He opened a 340 g can of soda and left it open for a day. The next day, he
measured the soda can again and found it was 332 g. Which statement below best explains why the masses were different?
A. The can was open and gases were released.
B. The can was a unopen and gases were released.
C. A mistake was made and the experiment should be conducted again because the Law of Conservation of Mass was violated.
D. A mistake was made in measuring the mass of the can.
Answer:
A - The can was open and gases were released.
Please help me fill in the blanks
Electrons first occupy the position in lowest possible energy.
orbital diagrams:-
The higher the energy level, the Third energy the electrons in that level have. On the orbital diagram, fill in the boxes to label the representations of an orbital and a sublevel. 2 electrons can occupy a single orbital, and these electrons have Opposite spin. Within a sublevel, all the orbitals fill with one electron, each of which has the Positive spin before a second electron fills any of the orbitals.
what is Orbital?
Each energy position is made up of areas known as an orbital. An orbital is an area of probability in which electrons can be set up. Each energy position, except for the first, has further than one orbital. Each orbital has a specific shape.
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when might the BAC of a dead body be misleading or unhelpful
Answer: Blood alcohol levels at autopsy are valid up to 48 hours after death when simple principles are observed in the collection and storage of samples. Alcohol levels in samples of blood taken from the intact heart are as significant as levels of blood from the femoral veins.
Explanation:
Answer:
If the victim was submerged in water
Explanation:
Calculate the mass of compound (molar mass = 256 g [tex] mol {}^{-1} [/tex] ) to be dissolved in 75g of benzene to lower its freezing point by 0.48K
( [tex]K _{f} = 5.12 \: K \: \: kg \: mol { }^{ - 1} [/tex] )
thankyou.
The mass of the compound is calculated by freezing point depression formula which is ΔTf=Kf×W₂×1000/M₂×W₁ which is equal to 3125 g.
What is a compound?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.
Freezing point depression is calculated by the formula, ΔTf=Kf×W₂×1000/M₂×W₁ .Therefore,W₁=5.12×75×1000/0.48×256=3125 g.
Thus, mass of compound is 3125 g.
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order these elements by decreasing electron affinity:
Na, Al, S, K, F
Answer:
increasing to decreasing:
F--- S--- Al--- Na--- K
not sure...
Please help me I really need the help
Thermal energy is the sum of all the potential and kinetic energy of the atoms within a system that is responsible for its temperature.
How to conclude the Electro negativity?Friction transforms other forms of energy into thermal energy. Atoms are the building blocks of matter. Atoms are composed of subatomic particles called protons, neutrons, and electrons.Periodic trends are patterns on the periodic table that illustrate elements’ characteristics.Significant trends are atomic radius, metallic reactivity, electronegativity, electron affinity, and ionization energy.
Atomic radius and metallic reactivity trends: They increase when they move down a group and left across a period.Electronegativity, electron affinity, and Ionization energy trends: They increase when they move up a group and right across a period.
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Alkaline water 8.0, Fruit juice 6.8, Gatorade 3.0, Green tea 9.0, Gatorade 3.0, Vinegar 3.5,
a. Organize this list of foods with pH from most basic to most acidic.-
Answer: See explanation
Explanation:
The pH scale is used to measures how acidic an object is. It should be noted that the objects that are basic aren't very acidic. The most acidic has values of 0 while the most basic has value of 14, 7 is known to be neutral.
Therefore, list of foods with pH from most basic to most acidic will be:
Green tea 9.0,
Alkaline water 8.0
Fruit juice 6.8
Vinegar 3.5,
Gatorade 3.0
2. The nonmetals in the Groups 16 and 17________
a) lose electrons when they form ions
b) gain electrons making them an anion
c) all have ions with a -1 charge
d) end in -ate
All of the ions in groupings 16 and 17 of nonmetals have a charge of -1. Spontaneous non-metals include brittle both thermally & electrically insensitive compounds.
What other names do non-metals have?Non-metals are elements that frequently gain electrons during chemical processes to generate anions. These substances are electronegative ones. They lack luster, are fragile, and are poor heat- and electricity-conductors (except graphite). Non-metals come in solid, liquid, or gaseous forms.
What 20 nonmetals are there?Lithium, Beryllium, Sodium, Mg, Aluminum, Potassium, & Calcium are the minerals within the first twenty elements. Hydrocarbons, Helium, Carbo, Nitrogen, Oxygen, Hydrochloric acid, Neon, Phosphorous, Sulphur, Chlorinated, and Argon now comprise the non-metals that comprise the first twenty elements.
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A 1500 L weather balloon is at 'a temperature of 290 K on the ground. As it rises the
temperature drops. At 15,000 ft, the temperature is down to 210 K. What is the
volume at this elevation?
Answer:
1086.2 L
Explanation:
The computation of the volume of the elevation is given below:
Here we assume the volume of the elevation be x
As we know that
V¹ ÷ T¹ = V² ÷ T²
Here
V^1 = 1500
T^1 = 290
V^2 = x
T^2 = 210
Now place these values to the above formula
So,
1500 ÷ 290 = x ÷ 210
x = 1086.2 L
waves in a lake are 5.00m in length and pass an anchored boat 1.25 s apart. the speed of the waves is:
a. 0.25 m/s
b. 4.00 m/s
C. 6.25 m/s
d. 3 × 108 m/s
Answer:
b. 4.00 m/s
Explanation:
divide the waves by the time
5÷1.25=4
In the next set of boxes, enter the mass number and atomic number of the alpha particle,
which has the same composition as the nucleus of a helium (He) atom. After filling in the
boxes in the Gizmo, what is the atomic mass of the first element?
New mass number
238
U
+
92
New atomic number
Answer:
234
Explanation:
From the question given above, the following data were obtained:
Alpha particle => ⁴₂He
²³⁸₉₂U —> ? + ⁴₂He
Let the unknown be ⁿₓZ. Thus, the equation becomes
²³⁸₉₂U —> ⁿₓZ + ⁴₂He
Next, we shall determine x, y and Z. This can be obtained as follow:
92 = x + 2
Collect like terms
92 – 2 = x
90 = x
x = 90
238 = n + 4
Collect like terms
238 – 4 = n
234 = n
n = 234
ⁿₓZ => ²³⁴₉₀Z => ²³⁴₉₀Th
Thus the balanced equation
²³⁸₉₂U —> ²³⁴₉₀Th + ⁴₂He
Therefore, the atomic mass of the first element is 234
Answer:
A: 234
B: 90
C: Th
D: 4
E: 2
F: He
Thank You!
Cells grouped together to make a specific part of the body of a plant or animal are called: an organism photosynthesis a tissue
Answer:
THE CORRECT ANWER IS ;Cells make up tissues, tissues make up organs, and organs make up organ ... All the systems of the body work together to keep an organism up and running. ... out a particular function, and groups of organs with related functions make up the ... Connective tissue supports and, as the name suggests, connects other tissues.
Explanation:
Answer: The correct answer to this question is "a tissue.
Explanation: "Tissue is a term used to describe a group of cells that have similar structure and function and work together to carry out a specific function in the body of a plant or animal.For example, muscle tissue is made up of muscle cells that work together to help the body move, while nervous tissue is made up of nerve cells that transmit signals throughout the body.An organism is a living entity that can carry out all of the basic life processes, while photosynthesis is the process by which plants use sunlight, carbon dioxide, and water to produce food in the form of glucose.
How many calcium ions are in 0.9 mol of CaCl2?
× 10 Ca2+ ions Enter your answer in scientific notation.
Answer: There are [tex]5.42 \times 10^{23}[/tex] [tex]Ca^{2+}[/tex] ions present in 0.9 mol of [tex]CaCl_{2}[/tex].
Explanation:
According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] atoms present in one mole of a substance.
As here, 0.9 mol of [tex]CaCl_{2}[/tex] are present. Also, there is only one atom of Ca is present in a molecule of [tex]CaCl_{2}[/tex].
Hence, calcium ions present in 0.9 mol of [tex]CaCl_{2}[/tex] are calculated as follows.
[tex]No. of ions = 1 \times 0.9 \times 6.022 \times 10^{23}\\= 5.42 \times 10^{23}[/tex]
Thus, we can conclude that there are [tex]5.42 \times 10^{23}[/tex] [tex]Ca^{2+}[/tex] ions present in 0.9 mol of [tex]CaCl_{2}[/tex].
What would be the cathode in a magnesium and zinc galvanic cell?
O A. Mg2+
OB. Zn(s)
OC. Zn²+
OD. Mg(s)
The correct answer is C. Zn²+. In a magnesium and zinc galvanic cell, the anode is the magnesium (Mg(s)) and the cathode is the zinc (Zn²+).
What is zinc galvanic cell?A zinc galvanic cell is an electrochemical device that uses a zinc anode and a cathode of a different material, usually copper, to produce electricity. The reaction that occurs in the cell is a redox reaction, which involves the oxidation of zinc at the anode and the reduction of copper at the cathode.
Zn²+. In a magnesium and zinc galvanic cell, the anode is the magnesium (Mg(s)) and the cathode is the zinc (Zn²+). In this cell, the magnesium metal is oxidized to form Mg2+ ions which are released into the solution. The zinc ions (Zn²+) are then reduced to zinc metal (Zn(s)) at the cathode.
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Answer: B
Explanation:
Fe2O3 + 6HCl → 2FeCl3 + 6H20 How many atoms of FeCl3 will be produced if 9.3 x 1023 atoms of HCl are used for this reaction? 6.7 x 1023 atoms FeCl3 3.1 x 1023 atoms FeCl3 9.3 x 1023 atoms FeCl3 1.2 x 1023 atoms FeCl3
Answer:
3.1x10²³
Explanation:
I'm going to answer the question assuming the number of molecules of FeCl₃ is asked, rather than the number of atoms.
Fe₂O₃ + 6HCl → 2FeCl₃ + 6H₂OFirst we convert 9.3x10²³ atoms of HCl into moles of HCl, using Avogadro's number:
9.3x10²³ atoms ÷ 6.023x10²³ atoms/mol = 1.54 mol HClThen we convert 1.54 moles of HCl into moles of FeCl₃, using the stoichiometric coefficients of the reaction:
1.54 mol HCl * [tex]\frac{2molFeCl_3}{6molHCl}[/tex] = 0.51 mol FeCl₃Finally we calculate how many FeCl₃ molecules are there in 0.51 moles:
0.51 mol * 6.023x10²³ molecules/mol = 3.4x10²³ moleculesThe closest option is 3.1x10²³.
The number of atoms produced is four times the number of FeCl₃ molecules produced.
A sample of helium was compressed at 35 °C from a volume of 0.5 L to 0.25 L where the pressure is 500 mmHg. What was the original pressure?
Answer:
The ideal gas law is a formula that relates the pressure, volume, temperature, and number of moles of a gas. It can be expressed as:
PV = nRT
where P is the pressure of the gas, V is the volume of the gas, n is the number of moles of the gas, R is the gas constant, and T is the temperature in Kelvin.
Since the number of moles and the temperature are constant in this problem, we can rearrange the formula to solve for the pressure:
P = (nRT) / V
Plugging in the known values, we get:
P = (nRT) / V
= (n * R * (35 + 273)) / 0.25 L
= (n * R * 308 K) / 0.25 L
We are given that the pressure is 500 mmHg and the volume is 0.25 L at this pressure, so we can set these equal:
500 mmHg = (n * R * 308 K) / 0.25 L
Solving for n, we get:
n = (500 mmHg * 0.25 L) / (R * 308 K)
We know that the pressure and volume of the gas at its original state are what we are trying to solve for. Let's call the original pressure P_0 and the original volume V_0. We can then express the relationship between the original and final state of the gas as:
P_0 * V_0 = n * R * T
Substituting the expression we found for n and the known values, we get:
P_0 * V_0 = ((500 mmHg * 0.25 L) / (R * 308 K)) * R * 308 K
Solving for P_0, we get:
P_0 = (500 mmHg * 0.25 L) / (R * 308 K) * (R * 308 K) / V_0
= (500 mmHg * 0.25 L) / (V_0)
Since V_0 = 0.5 L, we can substitute this value to get:
P_0 = (500 mmHg * 0.25 L) / (0.5 L)
= 500 mmHg / 2
= 250 mmHg
Therefore, the original pressure of the gas was 250 mmHg.
Calculate the pH of the solution produced by adding 10mL of 1M hydrochloric acid to 1L of a solution which is 0.1M acetic acid and 0.1M in sodium acetate (Ka = 1.75 x 10-5 molL-1. Comment on the variation in pH.
A buffer solution is one in which the pH of the solution is "resistant" to small additions of either a strong acid or strong base. Buffers usually consist of a weak acid and its conjugate base, in relatively equal and "large" quantities. Calculations are based on the equation for the ionization of the weak acid in water forming the hydronium ion and the conjugate base of the acid. "HA" represents any weak acid and "A-" represents the conjugate base.
HA(aq) + H2O(l) --> H3O+(aq) + A-(aq)
Ka = [H3O+][A-]
The name of an alcohol side chain is known as an alkoxy group. True or false?
why is oxygen more electronegative than nitrogen
Answer:
Oxygen has 8 protons in the nucleus while nitrogen only has 7. A bonding pair will experience more attraction from the oxygen's nucleus than from nitrogen's, and so the electronegativity of oxygen is greater.
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In KClO3, the proportions of K, Cl, and O are 31.9%, 28.9%, and 39.1%, respectively.
KClO3: Is it an acid or a base?There are three ways to define bases and acids. A strong base and a strong acid, respectively, called KOH K O H and HClO3 H C l O 3, react to form KClO3 K C l O 3, a salt.
Who or what is KClO3?A powerful oxidising agent with several applications is potassium chlorate (KClO3). It is or has formerly been a part of fireworks, explosives, safety matches, and disinfectants. The disproportionation of sodium hypochlorite results in the formation of sodium chloride and sodium chlorate initially.
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An unknown substance is obtained by police. The forensics laboratory has
determined it is made of nitrogen and oxygen. If 74.66 grams are nitrogen
and the police obtained a 250 gram sample, what is the percent
composition of oxygen in the sample?
Answer:
70.0 %
Explanation:
Step 1: Given data
Mass of nitrogen (mN): 74.66 gMass of the compound (mNxOy): 250 gStep 2: Calculate the mass of oxygen (mO) in the compound
The mass of the compound is equal to the sum of the masses of the elements that form it.
mNxOy = mN + mO
mO = mNxOy - mN
mO = 250 g - 74.66 g = 175 g
Step 3: Determine the percent composition of oxygen in the sample
We will use the following expression.
%O = mO / mNxOy × 100%
%O = 175 g / 250 g × 100% = 70.0 %
which nucleus experiences a stronger net force holding its protons and neutrons togeter unanium or or barium
Answer:
Uranium experiences a stronger net force holding its protons and neutrons together than barium.
Explanation:
Rifampin has a long aliphatic chain forming a bridge between an aromatic moiety (naphthaline).
a. True
b. False
Answer:
True
Explanation:
Question - Rifampin has a long aliphatic chain forming a bridge between an aromatic moiety (naphthaline).
Solution -
It is a true statement.
So,
The correct option is - True.
Reason -
Rifampin has a long aliphatic chain forming a bridge between an aromatic moiety (naphthaline)
When was the "Permian Era"?
Answer:
298.9 million years ago - 251.902 million years ago
Explanation:
It might be in the 2011 Earth Science Review Packet so maybe go check that out
is the enthalpy change when 1 mole of a substance undergoes complete
combustion under standard conditions.
Answer:
Explanation:
Standard enthalpy of combustion (ΔH∘C) is the enthalpy change when 1 mole of a substance burns under standard state conditions;
what is POH of a solution containing hydrogen ion concentration of 0.008
Given-
Hydrogen ion concentration pH = 0.008
Now,
we know that pH + pOH = 14
pOH = 14-0.008
pOH = 13.992