Answer:
250 minutes
Explanation:
I hope you do well
A sample of helium has a temperature of 450 K. The gas is cooled to 248.9 K at which time the gas occupies 103.4 L? Assume pressure is constant at 3 atm. What was the original volume of the gas?
A. 186.94 L
B. 304.5 L
C. 57.19 L
D. 361.07 L
Answer:
[tex]\boxed {\boxed {\sf A. \ 186.94 \ L}}[/tex]
Explanation:
We are asked to find the original volume of a gas given a change in temperature. Since pressure remains constant, we are only concerned with volume and temperature, so we use Charles's Law. This states the volume of a gas is directly proportional to the temperature. The formula for this law is:
[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]
The gas begins with a temperature of 450 Kelvin, but the volume is unknown.
[tex]\frac {V_1}{450 \ K }= \frac{V_2}{T_2}[/tex]
The gas is cooled to 248.9 Kelvin and the gas occupies a volume of 103.4 liters.
[tex]\frac {V_1}{450 \ K }= \frac{103.4 \ L}{248.9 \ K}[/tex]
Since we are solving for the original volume, we must isolate the variable V₁. It is being divided by 450 Kelvin. The inverse operation of division is multiplication, so we multiply both sides of the equation by 450 K.
[tex]450 \ K \frac {V_1}{450 \ K }= \frac{103.4 \ L}{248.9 \ K}* 450 \ K[/tex]
[tex]V_1= \frac{103.4 \ L}{248.9 \ K}* 450 \ K[/tex]
The units of Kelvin cancel.
[tex]V_1= \frac{103.4 \ L}{248.9 }* 450[/tex]
[tex]V_1= 0.4154278827 \ L *450[/tex]
[tex]V_1= 186.9425472 \ L[/tex]
Round to the nearest hundredth. The 2 in the thousandths place tells us to leave the 4 in the hundredth place.
[tex]V_1 \approx 186.94 \ L[/tex]
The original volume is approximately 186.94 liters and Choice A is correct.
Determinar el volumen de 20 kg de benceno si su densidad es de 0,88g/cm3
Answer:
volume = mass/ densidad
0.88g/cm3 = 880kg/m3
v=20kg/880kg/m3
v=0.02272727272
o puede ser 0.0227
o tambien puede ser 0.023
A fixed mass of gas has a volume of 92 cm cube and 3 degrees Celsius. What will be its volume at 18 degrees celsius if the pressure remains constant?
Answer:
94.8454
Explanation:
Let volume be V
Let Temperature be T
V1= 92
T1= 3C but to kelvin 273+3= 300K
V2= ?
T2= 18 C but to kelvin 18+273= 291
[tex] \frac{v1}{t1} = \frac{v2}{t2} [/tex]
[tex] \frac{92}{300} = \frac{v2}{291} [/tex]
[tex]v2 \times 300 = 92 \times 291[/tex]
[tex]v2 = \frac{92 \times 291}{300} [/tex]
[tex]v2 = 94.8454[/tex]
Which of the following pairs of compounds have the same empirical formula?
a. acetylene, C2H2, and benzene, C6H6
b. ethane, C2H6, and butane, C4H10
c. nitrogen dioxide, NO2, and dinitrogen tetroxide, N2O4
d. diphenyl ether, C12H10O, and phenol, C6H5OH
Answer:
option a and c both are correct
Explanation:
please mark me as brainliest
The pairs of compounds have the same empirical formula are:
a. acetylene, C₂H₂, and benzene, C₆H₆ and
c .nitrogen dioxide, NO₂, and di nitrogen tetroxide, N₂O₄
What is empirical formula?The empirical formula of a compound is defined as the formula that shows the ratio of elements present in the compound, but not the actual numbers of atoms found in the molecule.
In some cases, the empirical formula is the same as the molecular formula, which gives the actual number of atoms in a compound (e.g., H₂O).Otherwise, the molecular formula is a multiple of the empirical formula (e.g., CH₂O is the empirical formula for glucose, C₆H₁₂O₆).
Examples of empirical formulas:
Glucose has a molecular formula of C₆H₁₂O₆. It contains 2 moles of hydrogen for every mole of carbon and oxygen. The empirical formula for glucose is CH₂O.
The molecular formula of ribose is C₅H₁₀O₅, which can be reduced to the empirical formula CH₂O.
The pair with empirical formula is acetylene, C₂H₂, and benzene, C₆H₆ and
nitrogen dioxide, NO₂, and di nitrogen tetroxide, N₂O₄
Thus, option (A) and (C) are correct.
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Compare and contrast qualitative and quantitative data.
Answer: Qualitative data typically consists of words while quantitative data consists of numbers.
Explanation:
What is the pressure of 4 moles of helium in a 50 L tank at 308 K?
Use PV = nRT.
A. 24.64 atm
B. 0.13 atm
O C. 0.51 atm
D. 2.02 atm
Answer:
D
Explanation:
P = Pressure
V = Volume
n = Moles
R = .08206 (because we're using liters)
T = Temperature (as K)
P(50) = (4)(.08206)(308)
P(50) = 101.09792
Divide both sides by 50
P(50)/50 = 101.09792/50
P = 2.0219584
Answer:
[tex]\boxed {\boxed {\sf D. \ 2.02 \ atm}}[/tex]
Explanation:
We are asked to find the pressure of helium gas using the ideal gas law.
[tex]PV= nRT[/tex]
In this formula P is the pressure, V is the volume, n is the number of moles of gas, R is the universal gas constant, and T is the temperature.
The pressure is unknown and we are solving for it. The volume is 50 liters, there are 4 moles of helium gas, the universal gas constant is 0.08206 L *atm/ mol * K, and the temperature is 308 Kelvin.
[tex]\bullet \ V= 50 \ L \\\bullet \ n= 4 \ mol \\\bullet \ R = \frac {0.08206 \ L * atm}{mol *K}\\\bullet \ T= 308 \ K[/tex]
Substitute these values into the formula.
[tex]P * 50 \ L= 4 \ mol * \frac {0.08206 \ L * atm}{mol *K} * 308 \ K[/tex]
Multiply on the right side. The units of moles (mol) and Kelvin (K) cancel each other out.
[tex]P* 50 \ L = 4 * 0.08206 \ L *atm * 308[/tex]
[tex]P*50 \ L =0.32824 \ L * atm *308[/tex]
[tex]P* 50 \ L = 101.09792 \ L * atm[/tex]
We are solving for the pressure, so we must isolate the variable P. It is being multiplied by 50 liters. The inverse operation of multiplication is division, so divide both sides by 50 L.
[tex]\frac {P* 50 \ L}{50 \ L} = \frac {101.09792 \ L * atm}{50 \ L}[/tex]
[tex]P= \frac {101.09792 \ L * atm}{50 \ L}[/tex]
The units of liters (L) cancel.
[tex]P= \frac{101.09792}{50 } \ atm[/tex]
[tex]P= 2.0219584 \ atm[/tex]
If we round to the nearest hundredth place the 1 in the thousandth place tells us to leave the 2 in the hundredth place.
[tex]P \approx 2.02 \ atm[/tex]
The pressure is approximately 2.02 atmospheres and choice D is correct.
PLZ HELP ME Which of the following is the process by which chloroplasts use carbon dioxide, water, and sunlight to produce sugars and oxygen?
A. Photosynthesis
B. Cellular respiration
c. Reproduction
D. Homeostasis
Answer:
a
Explanation:
Which of the following type of matter has weakest interparticle force of attraction O a. Liquid water
O b. Iron
O c. Steam
O d. sand
Answer:(b)liquid water is correct option . Because it is a molecular solid and molecular solid has weak interparticle forces of attraction
Explanation:
cho 3,8g hỗn hợp na2co3 và nahco3 tác dụng với dung dịch hcl.Thoát ra 896 khí ở đktc a/ tính thành phần % theo khối lượng mỗi muối trong hỗn hợp đều.b/ tính thể tích dung dịch hcl 20% biết d= 1,1g trên ml
Answer:
99
Explanation:
it is matter so it and it has.bein 99
Define physical and chemical properties, provide three examples of each, discuss their reversibility, and explain the fundamental differences between them.
Answer:
Physical properties are defined as the properties which can be observed without changing their chemical composition.
For example, color, volume, and molecular weight.
Chemical properties can be defined as, a properties that can be seen only after changing the substance's chemical identity.
For example, reactivity, toxicity, and flammability.
The fundamental differences between physical and chemical properties are as follows:
Chemical properties are related to chemical bonds of the substance, while physical properties are not.
In chemical properties, the chemical identity of substance changes while physical properties does not have any change.
Chemical properties predict the reaction of a substance, while physical properties only describe the appearance of the substance.
Explanation:
Which of the following is an example of a chemical change?
A. Sugar breaking down into water and carbon when it is heated
B. A sugar cube being crushed by a spoon
C. Sugar mixing with red food coloring and forming a red solid
D. A sugar cube dissolving in water as the water is stirred
Answer:
I think its sugar breaking down into watee and carbon when it is heated
I HOPE ITS RIGHT IF NOT THEN SORRYHAVE A GREAT DAY :)
What is the difference between a strong base and a weak base?
A. A strong base is always more concentrated than a weak base,
B. A strong base has a lower Ki than a weak base.
C. A strong base produces more ions in solution than a weak base,
D. A strong base is not as conductive as a weak base.
Answer:
C
Explanation:
Question 2: thanks!!!
Balance the redox reaction by oxidation number or ion electron method and indicate oxidizing and reducing agent . KMno4 + KBr + H2SO4 approach K2SO4 + MnSO4 + H2O + Br2
Answer:
2KMnO₄ (aq) + 10KBr (aq) + 8H₂SO₄ (aq) -> 2MnSO₄ (aq) + 5Br₂ (aq) + 6K₂SO₄ (aq) + 8H₂O (l)
oxidizing agent = KMnO₄
reducing agent = KBr
Explanation:
KMnO₄ -> 2Mn⁷⁺ + 10e⁻ = 2Mn²⁺
KBr -> 10Br⁻⁺ - 10e⁻ = 10Br⁰
1125 J of energy is used to heat 250 g of iron to 55 °C. The specific heat capacity of iron is 0.45 J/(g·°C).
What was the temperature of the iron before it was heated?
55 °C
55 °C
35 °C
35 °C
45 °C
45 °C
20 °C
Answer:
45 °C.
Explanation:
From the question given above, the following data were obtained:
Heat (Q) = 1125 J
Mass (M) = 250 g
Final temperature (T₂) = 55 °C
Specific heat capacity (C) = 0.45 J/gºC
Initial temperature (T₁) =?
The initial temperature of the iron can be obtained as illustrated below:
Q = MC(T₂ – T₁)
1125 = 250 × 0.45 (55 – T₁)
1125 = 112.5 (55 – T₁)
Divide both side by 112.5
1125/112.5 = 55 – T₁
10 = 55 – T₁
Collect like terms
10 – 55 = –T₁
–45 = –T₁
Multiply through by –1
45 = T₁
T₁ = 45 °C
Therefore, the initial temperature of the iron is 45 °C
solution is an example of______mixtures
Answer:
homogeneous mixture must be the answer
write a balanced chemical equation for the reaction between CO2,H2O, Naclo3 and H2O2
Answer:
2H2O2 + NaClO → NaClO3 + 2H2O
What are the units of molar mass?
A. L/g
B. mol/g
C. g/L
D. g/mol
SUBST
Answer:
D - g/mol
step by step method
2 Figure 3.1 shows two different forms of carbon, A and B.
A
B
Figure 3.1
a Name the two forms of carbon shown.
Answer:
show the pictures pls specify
2.
In photosynthesis, which substances are used up, which are produced and which are necessary
but remain unchanged after the reaction?
used up
produced
remain
A
carbon dioxide
water
oxygen
A
8
chlorophylt
carbon dioxide
water
с
oxygen
starch
cellulose
D
water
oxygen
chlorophyll
D. Water is used up, Oxygen is produced and Chlorophyll is necessary, but remains unchanged.
how can you identify if a physical or chemical change has occurred
Answer:
The difference between a physical reaction and a chemical reaction is what its made of. In a chemical reaction, there is a change in the materials of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. Whereas will a chemical change there is not.
Answer:
Answer:
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds. Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color chage, formation of a precipitate, formation of a gas, odor change, temperature change. Change in Color. Noticeable Odor (after reaction has begun) Formation of a Precipitate. Formation of Bubbles. Physical changes are changes that do not alter the identity of a substance. Chemical changes are changes that occur when one substance is turned into another substance. Chemical changes are frequently harder to reverse than physical changes
Explanation:
The unit of force newton is a derived unit.Why?
Answer:
Why is the unit of force called a derived unit? That's because the Newton is defined in terms of other units which are more fundamental. One Newton is the force required to accelerate a mass of one kilogramme at the rate of one metre per second squared.
write the electronic configuration of the first 20 element
step by step of how to convert fahrenheit and celsius to kelvins -5F to kelvins please and thank you
Infrared waves are an example of heat transfer by
A. convection
B. radiation
C. conduction
D. motion of the air
Answer:
convection is my correct answer
An man in Arkansas recently found a 9 carat diamond at Crater of Diamonds State Park. Five carats are equivalent to one gram, so this diamond weighs 1.8 g. Diamond is a crystalline form of the element carbon. How many atoms of carbon are in this 1.8 g diamond
Answer:
The answer is "1.8 g diamond includes 9.03e22 atoms".
Explanation:
Given:
Weight of 9-carat diamond = 1.8 g
[tex]\therefore\\\\[/tex]
weight of 1-mole carbon =12 g
[tex]\because[/tex]
calculating the moles which are available into 18 g carbon weight:
x= Carbon moles weight in 1.8 g
[tex]1 - mol\ C = 12 g\\\\x - mol\ C = 1.8 g\\\\\to x = \frac{(1.8 \ g \times 1\ mol\ C)}{ 12 \ g}\\\\\to x = 0.15\ moles[/tex]
In 1 mole element associated with Avogadro's number that is [tex]6.02 \times 10^{23}\\\\[/tex]
Carbon includes in 1 mol[tex]=6.02 \times 10^{23}\ atoms\\\\[/tex]
0.15 mol of carbon includes:
[tex]= 0.15 \times 6.02 \times 10^{23} = 9.03 \times 10^{22}\ atoms.[/tex]
Using the scientific notation:
0.15 mol of carbon includes: 9.03e22 atoms. So, 1.8 g diamond includes 9.03e22 atoms.
Please tell me the answer of what is unit?
Answer:
a quantity chosen as a standard in terms of which other quantities may be expressed.
Explanation:
Explanation:
Unit is a standard physical quantity defined and adopted by convention,with other quantity of same kind.
which statement best describes a chemical property of a mineral
Answer:
The mineral forms gas bubbles when a sample is stored in water
Describe how a constant volume calorimeter can be used to measure the heat transferred from a burning piece of coal to cool water.
thank you <3
Answer:
A Calorimeter is a device used to measure the amount of heat involved in a chemical or physical process.
Explanation:
Ex- when an exothermic reaction ( accompanied by or requiring absorption of heat)occurs in solution in a calorimeter, the heat produced by the reaction is absorbed by the solution increasing its temperature.
- When an endothermic reaction (Heat evolving reaction) occurs, the heat required is absorbed from the thermal energy of the solution, decreasing its temperature.
A burning piece of coal which is releasing heat due to its combustion and is transferred to water.
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What is an alkyne?
A. A hydrocarbon containing all single bonds
B. A hydrocarbon containing a carbon-carbon double bond
C. A hydrocarbon containing a carbon-carbon triple bond
D. A hydrocarbon containing an aromatic ring
Alkynes are called the hydrocarbons. Ethyne is an important alkyne which is used in oxyacetylene gas cutting. A hydrocarbon containing a carbon-carbon triple bond is the alkyne. The correct option is C.
What is an alkyne?In organic chemistry, an alkyne is defined as the unsaturated hydrocarbon containing at least one carbon-carbon triple bond. The alkynes are unsaturated hydrocarbons and their general formula is CₙH₂ₙ₋₂ and the triple bond is known as the acetylene bond.
Many alkynes are found in nature. Ethyne is the first member of the alkyne family in which two carbon atoms are connected by a triple bond. Almost all alkynes are also found to be hydrophobic in nature.
Alkynes show three types of isomerism like chain isomerism, position isomerism and functional isomerism. The triple bond present in the alkynes is its functional group.
Thus the correct option is C.
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