Answer:
10.43 / 342 × 6.02 × 10 ^23 = 18.34 × 10^ 21
When 1 mol of methane is burned at constant pressure, −890 kJ/mol of energy is released as heat. If a 1.67 g sample of methane is burned at constant pressure, what will be the value of ∆H
Answer:
[tex]\Delta H=-92.7kJ[/tex]
Explanation:
Hello there!
In this case, according to the given information, we can infer that 890 kJ of energy are released when 1 mole of methane is burned; however, to find the total heat when 1.67 grams are burned, we first need to calculate the moles in this mass of methane:
[tex]1.67gCH_4*\frac{1molCH_4}{16.04gCH_4}=0.104molCH_4[/tex]
And thus, for calculating the resulting ∆H, we proceed as follows:
[tex]\Delta H=-890kJ/mol*0.104mol\\\\\Delta H=-92.7kJ[/tex]
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Pls answer this Il give brainiest question in picture ty
Answer:
c
Explanation:
troposphere is the answer
PLEASE QUICKLY. I'll give BRAINLIEST. A sample contains 25% parent isotope and 75% daughter isotopes. If the half-life of the parent isotope is 72 years, how old is the sample?
144 years old
216 years old
288 years old
360 years old
From the calculations and the principles of radioactivity, the age of the parent isotope is 144 years
What is radioactivity?The term radioactivity has to do with the spontaneous decay of a substance.
We know that we have about 25% parent isotope still remaining hence;
[tex]0.693/t1/2 =2.303/t log No/N\\When N =0.25 No and t1/2 = 72 years\\0.693/72 =2.303/t log No/0.25No\\0.0096 = 2.303/t *0.60206\\0.0096 = 1.3865/t\\t = 1.3865/0.0096\\t =144 years[/tex]
Learn more about radioisotope:https://brainly.com/question/13076859
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Answer:
A. 144 years old
Explanation:
Balance the following equation:
Cr + __02 +_Cr203
Answer:
4Cr + __302 -->_2Cr203.....
Mole ratios used for conversions come from?
the tissue which continually forms new cells in plants
Answer:
Meristematic Tissues. Tissues where cells are constantly dividing are called meristems or meristematic tissues. These regions produce new cells.
Explanation:
thank me later
What is diffusion? How does the motion of gas molecules explain how a gas diffuses throughout a room?
Answer:
Diffusion in gases
Diffusion is driven by differences in concentration. When chemical substances such as perfume are let loose in a room, their particles mix with the particles of air. The particles of smelly gas are free to move quickly in all directions
Explanation:
hope this helps
Energy that is made from the power of moving water
a
b
ОООО
wind
hydroelectric
coal
с
d
biomass
Hydroelectric energy is produced.
How do you think the human population has changed over time? What makes you say that?
Answer:The world population increased from 1 billion in 1800 to 7.7 billion today. The world population growth rate declined from 2.2% per year 50 years ago to 1.05% per year. Other relevant research: World population growth – This article is focusing on the history of population growth up to the present.
Explanation:
How many formula units are there in 14.50 moles of any compound?
___X 10^___formula units
Answer:
8.73 × 10²⁴ formula units
Explanation:
To calculate the number of formula units a substance contain, we multiply the number of moles by Avagadro number (6.02 × 10²³)
number of formula units = 14.50 moles × 6.02 × 10²³
= 87.29 × 10²³
= 8.73 × 10²⁴ formula units.
When temperature drops, (for example from 20 degrees celsius to 10 degrees celsius)
a.) energy increases
b.) particles move slower
c.) particles collide more often
d.) pressure increases
Answer:
In the Celsius scale each degree is one part of 100 degrees. This is because in this scale the difference between boiling and freezing temperatures of water is 100 ° - 0 ° = 100 °, so one degree Celsius is one part of 100.
In the Farhenheit scale, each degree is one part of 180 degrees. This is because in this scale the difference between the boiling and freezing temperatures are 212 ° - 32 ° = 180°, so one degree Fahrenheti is one part of 180.
That means that 1 °C is a larger amount than 1 °C, so 20°C is a larger amount than 20°F.
Conclusion: 20 degree change represents a larger change in Celsius scale.
Explanation:
In the Celsius scale each degree is one part of 100 degrees. This is because in this scale the difference between boiling and freezing temperatures of water is 100 ° - 0 ° = 100 °, so one degree Celsius is one part of 100.
In the Farhenheit scale, each degree is one part of 180 degrees. This is because in this scale the difference between the boiling and freezing temperatures are 212 ° - 32 ° = 180°, so one degree Fahrenheti is one part of 180.
That means that 1 °C is a larger amount than 1 °C, so 20°C is a larger amount than 20°F.
Conclusion: 20 degree change represents a larger change in Celsius scale.
The chemical equation for zinc in hydrochloric acid is: Zn + HCI = ZnCl2 + H2
Does the above equation demonstrate the law of conservation of mass as it is currently written? Explain why or why not.
Answer: No it does not
Explanation:
The law of conservation of mass states that mass is neither created nor destroyed and in this equation you start with 1 molecule of Cl and 1 of H, but on the reactants side you end up with 2 of each. To make it follow the law of conservation of mass you would have to balance the equation
A Starting substance in a chemical reaction is called a _______________.
1. reactant
2. product
3. chemical reaction
4. physical reaction
Answer:
1.)REACTANT
These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products.High levels and long periods of stress can increase a person’s risk for many diseases.
True
False
Answer:
true
Explanation:
Please help me I will give brainliest to the first correct answer
Answer:
OPTIC B) HEPT-HOPE IT IS HELPFUL
how many moles are in 0.14g of Nitrogen, N2?
Answer:
0.01 moles
Explanation:
14 g contains 1 mole
0.14g contains> (0.14*1)/14
= 0.01 moles
An ideal gas is contained in a cylinder with a volume of 5.0x102 mL at a temperature of 30°C and a pressure of 710. Torr. The gas is then compressed to a volume of 25 mL, and the temperature is raised to 820° C. What is the new pressure of the gas?
Answer:
51207 torr is the new pressure of the gas
Explanation:
We can solve this question using combined gas law that states:
P1V1T2 = P2V2T1
Where P is pressure, V volume and T absolute temperature of 1, initial state and 2, final state of the gas
Computing the values of the problem:
P1 = 710torr
V1 = 5.0x10²mL
T1 = 273.15 + 30°C = 303.15K
P2 = ?
V2 = 25mL
T2 = 273.15 + 820°C = 1093.15K
Replacing:
710torr*5.0x10²mL*1093.15K = P2*25mL*303.15K
3.881x10⁸torr*mL*K = P2 * 7.579x10³mL*K
P2 = 51207 torr is the new pressure of the gas
Gas particles that are at low temperature and high pressure and are close to changing phases are considered:
a)Real Gases
b)Ideal Gases
c)Both Ideal and Real Gases
How much energy required to raise the temperature of lead by the same degrees.
Answer:
If a one kilogram block of lead absorbs 2,000 J of energy then the temperature rise will be larger. If 1,000 J of heat is absorbed by a 2 kg block of lead then the temperature of the block doesn't rise as much since the energy is shared between more particles.
Explanation:
why metal in the middle of metal activity series can't be obtained by heating ors in air
Answer:
See Explanation
Explanation:
The way by which a metal is obtained from its ore is determined by the chemical reactivity of the metal.
Metals that are highly reactive are chiefly obtained by electrolysis of the metal salt. These metals are found high up in the metal activity series.
Metals that are at the middle of the series are moderately reactive and are obtained by electrolysis or by reduction since they still form ionic salts.
Metals that are far lower in the series can only be obtained by heating them in air because they are mostly unreactive.
Hence, moderately reactive metals at the middle of the series are not obtained by roasting in air.
The interaction of the skeletal and muscular systems to create movement and locomotion is regulated by which organ system?
Answer:
The muscoloskeletal system
Explanation:
The musculoskeletal system is made up of the body's bones (the skeleton), muscles, cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together. Its primary functions include supporting the body, allowing motion, and protecting vital organs.
The concentration of carbon-14 in a piece of wood from an ancient burial mound indicates that two half-lives of this radioisotope have passed. If the half-life (t 1/2) for carbon-14 is 5730 years, approximately how many years ago did this sample of wood die?
If the half-life for carbon-14 is 5730 years, then it will take 11,460 years to complete die of this sample.
What is half life period?Half life period is a time of decay in which concentration of reactant is left half of its initial concentration, means half of the reactant will convert into product.
Total time of decay will be calculated as:
T = (t)ⁿ, where
t = half life time = 5730 years
n = number of half lives = 2 (given)
On putting values, we get
T = (5730)² = 11,460 years
Hence required time for decay is 11,460 years.
To know more about half life time, visit the below link:
https://brainly.com/question/2320811
Answer:
The first part is 5 and the second part is 28,650
A gas has an initial pressure of 120 kPa, a volume of 23 liters, and a temperature of 20°C. If the pressure is raised to 150 kPa the new volume is 17 liters, what is the new temperature of the gas? *
A.100 K
B.0.003 K
C.270.7 K
D.18.4 K
is A tomato smells rotten a chemical
reaction
Answer:
yup
Explanation:
because chemical change took place
the reaction cant be reversible
How many grams of NaCl are in 1.25 X 1024
molecules of Naci? Use one decimal place
Answer:
121.1g
Explanation:
First, we need to convert the number of molecules of NaCl to moles (n) by dividing by Avagadro number
That is, n = number of molecules ÷ 6.02 × 10²³
n = 1.25 X 10²⁴ ÷ 6.02 × 10²³
n = 1.25/6.02 × 10^ (24-23)
n = 0.207 × 10¹
n = 2.07moles
Using the formula; mole = mass ÷ molar mass
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
mass = molar mass × mole
mass = 58.5 × 2.07
mass = 121.1g
How many grams of LiF are needed to make 87 g LiF solution into a
34.5% solution?
solution?
answer options:
30 g LIF
0.01 g LIF
45.8 g LIF
0.02 g LIF
Answer: 30 g LiF
Explanation:
Examine the food chain below: In this specific food chain, the _______ eats plants for food. A. caterpillar B. sunshine C. bobcat D. leaf
Someone please help me
Answer:reflection
Explanation:
What is the rate of diffusion of NO gas to CO gas?
Answer:
0.97
Explanation:
Let R₁ represent the rate of diffusion of NO.
Let R₂ represent the rate of diffusion of CO.
Molar mass of NO (M₁) = 14 + 16 = 30 g/mol
Molar mass of CO (M₂) = 12 + 16 = 28 g/mol
Thus, the rate of NO to CO can be obtained as follow:
R₁ /R₂ = √(M₂/M₁)
R₁ /R₂ = √(28/30)
R₁ /R₂ = √(28/30)
R₁ /R₂ = 0.97
R₁ : R₂ = 0.97
NO : CO = 0.97
Therefore, the rate of diffusion of NO to CO is 0.97
Another term for natural radioactive decay into another element is
Answer:
The process of unstable (or radioactive) atoms becomes stable by emitting radiation. This event over time is called radioactive decay. Alpha decay results in the loss of two protons and two neutrons from the nucleus
Answer:
radioactive disintegration
Explanation: