Answer:
Melting of ice
Explanation:
A physical change is one in which just the physical properties of the matter is altered. Most phase changes reaction falls under this type of change.
Examples are boiling, melting, freezing, condensation, sublimation, magnetization of metals, breaking glass, cutting wood. No new kinds of matter is formed. The process is reversibleNo change in massUsing the following thermochemical equation, calculate how much heat is associated with the decomposition of 4.00 moles of NH4Cl.
NH3(g) + HCl(g) è NH4Cl(s) ΔH = -176 kJ
A) 5000
B) 740
C) 407
D) 704
Answer:
D
Explanation:
[tex]4 \times - 176 = - 704[/tex]
Answer:
D - 704
Explanation:
The balanced thermochemical equation relates the energy change to moles, not grams, so we first convert the amount of NH4Ck to moles and then use the thermochemical equation to determine the energy change:
4.00 mole NH4Cl x (-176 ÷ 1 mole NH4Cl)
= -704
The system brings molecules to the cells. It includes blood vessels and the heart.
respiratory system
digestive system
circulatory system
nervous system
After pollen grows on a tube down the style,___
Answer:
as soon as the pollen reaches the stigma after the pollen grain descends down the style when the pollen tube grows into the ovule when the seed germinates
Explanation:
what is acide, Base and salt
Answer:
In acid – base chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. Basic salts contain the conjugate base of a weak acid, so when they dissolve in water, they react with water to yield a solution with pH greater than 7.0.
Explanation:
Hope this helped!
Why is the
chemical formula for sodium
chloride NaCl, and not NaCI6
or Na6CI
Answer: NaCl
Explanation:
Here You Go :)
Help me please!! :D
Answer: Solar eclipse
Explanation:
A newspaper article about the danger of global warming from the accumulation of greenhouse gases such as carbon dioxide states that "reducing driving your car by 20 miles a week would prevent release of over 1000 pounds of CO2 per year into the atmosphere." Is this a reasonable statement? Assume that gasoline is octane (molecular formula is C8H18) and that it is burned completely to CO2 and H2O in the engine of your car. Facts (or reasonable guesses) about your car's gas mileage, the density of octane, and other factors will also be needed.
Answer:
The newspaper article's statement is correct since the mass of CO₂ reduced = 1071.85 pounds
Explanation:
Equation for the combustion of gasoline (octane) is given below:
2C₈H₁₈ + 25O₂ ----> 16CO₂ + 18H₂O
Density of C₈H₁₈ = 0.8 g/mL
Assuming mileage of the car is 20 miles/gallon; 1 gallon = 3.785 L
Since 20 miles is reduced in driving each week, thereby saving 1 gallon of gasoline, number of litres of gasoline reduced in a year is given by;
52 * 3.785 L = 196.82 L = 196820 mL
density = mass/volume; mass = density * volume
mass of gasoline saved = 0.8 g/mL * 196820 mL = 157456 g
number of moles = mass/molar mass
Molar mass of C₈H₁₈ = 114 g/mol
number of moles of C₈H₁₈ in 157456 g = 157456 g / 114 g/mol = 1381.2 moles
From the equation of reaction, 2 moles of C₈H₁₈ produces 16 moles of CO₂
1381.2 moles of C₈H₁₈ will produce 1381.2 * 16/2 moles of CO₂ = 11049.6 moles of CO₂
mass = number of moles * molar mass
molar mass of CO₂ = 44 g/mol
mass of CO₂ = 11049.6 moles * 44 g/mol = 486182.4 g
1 g = 0.00220462 pounds
Therefore mass of CO₂ reduced = 486182.4 g * 0.00220462 lb/g
mass of CO₂ reduced = 1071.85 pounds
Therefore, the newspaper article's statement is correct
what is the element for I am a metal and I have 6 Neutrons. PLEASE ANSWER TO MY QUESTION QUICKLY!!!!
Answer:
carbon-12
Explanation:
carbon 6/12 isotope has 6 neutrones and it is considered as a metal.
Which type of stress causes fault-block mountains?
due is 10 min please help
Answer:
its c hope this helped;)
Explanation:
A wave is a _____that transfers _____ through a ______
A.) medium, disturbance, energy
B.) disturbance, energy, medium
C.) energy, disturbance, medium
D.)disturbance, medium, energy
A wave is a disturbance that transfers energy through a medium. There
are types of such as sound and light waves.
A wave involves the transfer of energy such as sound, light waves etc
through a medium. The medium could be through liquids , solids or air and
they have characteristic waves which pass through them.
When a wave transfers energy through a medium, the matter involved
doesn't experience any type of movement.
Read more on https://brainly.com/question/19210453
Name four amino acids. (site 2)
Answer:
phenylalanine, threonine, tryptophan, and valine. Srry I have these memorized.
Luther accidentally spilled his chemicals, and they splashed onto his arm and legs. Which piece of equipment should he use?
safety shower
eyewash station
fire blanket
fire extinguisher
Answer:
safety shower
Explanation:
its on his body, not his eyes, and fire safety wont help here.
The temperature of the water vapor (H,0) inside a pressure cooker increased from 295 K to 395 K. AS
the sample is heated, the pressure of the water vapor went from 21.0 kPa to
Answer:
P₂ = 28.12 KPa
Explanation:
Given data:
Initial temperature = 295 K
Final temperature= 395 K
Initial pressure = 21.0 KPa
Final pressure = ?
Solution:
According to Gay-Lussac Law,
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
21.0 KPa / 295 K = P₂/395 K
P₂ = 21.0 KPa× 395 K / 295 K
P₂ = 8295 KPa. K /295 K
P₂ = 28.12 KPa
where do rotten eggs get their terrible smell
Answer:
I found this in an article "There is frequently the odor of sulfur. This is due to a reaction between traces of iron in the yolk and sulfur in the white. It happens only when the eggs have been overcooked. Perfectly cooked yolks are moist and deep orange."
Explanation:
Hope that helps
Plants make their own food and are not required to consume food for energy. Into which category does this characteristic cause plants to be assigned?
Answer:
Autotrophic or Producers
Explanation:
They are often called producers because they make their own food.
A metal atom and a non-metal atom bond together. What type of bond do they form?
Question 8 options:
Ionic
Round
Covalent
Glue
Answer: Iconic
Explanation:Ionic bonds are formed through the exchange of valence electrons between atoms, typically a metal and a nonmetal.
calclulate the mass of one molecule of nitrogen in gram
Answer:
for its one mole it is of 28gram. according to mole concept in one mole, there is 6.022*10^23 moles are present. so mass of 1 molecule of nitogen gas is 28/(6.022*10^23)
Since the replication crisis, many practices have been implemented to improve research and promote –, or the practice of sharing data and materials so they can be reviewed and replicated by other researchers. One of these practices involves submitting the proposed methods and analysis plan to journals in advance for approval or –. This practice allows scientific journals to approve experiments before they are done, with the guarantee that any finding will be published regardless of whether or not it is significant. This process also prevents researchers from –, or creating theories or hypotheses that explain the results of a study after the data has been collected.
Answer:
Since the replication crisis, many practices have been implemented to improve research and promote open science, or the practice of sharing data and materials so they can be reviewed and replicated by other researchers. One of these practices involves submitting the proposed methods and analysis plan to journals in advance for approval or preregistration. This practice allows scientific journals to approve experiments before they are done, with the guarantee that any finding will be published regardless of whether or not it is significant. This process also prevents researchers from harking, or creating theories or hypotheses that explain the results of a study after the data has been collected.
Explanation:
The blanks in the text above were filled with the terms that best fit the context and meaning of the message that the text, in general, wanted to convey. No grammatical element and no punctuation has been modified, which allows the text to maintain its original coherence and meaning.
The added terms are in agreement with the scientific denominations currently accepted.
State the number of degrees of longitude that separates New York City from Denver, Colorado between these two cities.
Answer:
The number of degrees of longitude that separates New York City from Denver, Colorado is 30.9843 degrees longitude
Explanation:
The longitude of New York City is 74.0060° W
The latitude of New York City is 40.7128° N
The longitude of Denver, Colorado is 104.9903°W
The latitude of Denver Colorado is 39.7392°N
Therefore, the difference the number of degrees of longitude that separates New York City from Denver, Colorado is 104.9903 - 74.0060 = 30.9843°.
Which type of bond usually forms between two non metals
We breathe it out and it takes it in. Your next clue is where photosynthesis begins.
Answer:
Carbon Dioxide?
Explanation:
When we take a breath, we pull air into our lungs that contains mostly nitrogen and oxygen. When we exhale, we breathe out mostly carbon dioxide.
Choose all the answers that apply.
Plants in the desert _____.
have waxy leaves and stems
produce seeds quickly
don't need any water
lose their leaves in winter
Answer: They Have Waxy Leaves And Stems
Explanation:
:)
Answer:
have waxy leaves and stems
&
produce seeds quickly
Hope this helps good luck :)
Has food made us healthier the last 50 years ?
Answer:
no
Explanation:
no, because food has unhealthy products now especially from fast foods they add chemicals.
We can change the substance chemically by
freezing it.
True or false
Why do you think there are still smog events when there are pollution
control devices on smokestacks and vehicles?
Answer:
People just don't really seem to care about how much smog is being polluted anymore. So they still continue to go over the limit of smog and smoke that is supposed to be produced, which cause harm and damage to the environment around us. Hope this helps!
Explanation:
The force of attraction between one polar molecule and another polar molecule is
Answer:
Dipole-dipole forces
Explanation:
A polar compound is that compound which contains atoms that have a difference in charges i.e electrostatic attraction occurs between its constituent atoms. Polar molecules are attracted to other polar molecules with opposite charges and her held together with the aid of certain forces
The attractive force between the negative part of a polar molecule (-) and the positive part of another polar molecule (+) is called DIPOLE-DIPOLE FORCES. This dipole-dipole force gets stronger with an increasing polarity of the molecules involved.
Composition of matter (compound, mixture, element)
Explanation:
Matter can be classified into two broad categories: pure substances and mixtures. ... A material composed of two or more substances is a mixture. Elements and compounds are both examples of pure substances. A substance that cannot be broken down into chemically simpler components is an elementOne useful way of organizing our understanding of matter is to think of a hierarchy that extends down from the most general and complex to the simplest and most fundamental (Figure 3.4.1 ). Matter can be classified into two broad categories: pure substances and mixtures. A pure substance is a form of matter that has a constant composition (meaning that it is the same everywhere) and properties that are constant throughout the sample (meaning that there is only one set of properties such as melting point, color, boiling point, etc. throughout the matter). A material composed of two or more substances is a mixture. Elements and compounds are both examples of pure substances. A substance that cannot be broken down into chemically simpler components is an element. Aluminum, which is used in soda cans, is an element. A substance that can be broken down into chemically simpler components (because it has more than one element) is a compound. For example, water is a compound composed of the elements hydrogen and oxygen. Today, there are about 118 elements in the known universe. In contrast, scientists have identified tens of millions of different compounds to date.
An element is a substance which can be split into simpler unit by ordinary chemical prcess.
Compound this is a pure substance that is composed of two or more element in a fixed and definite portion.
Mixture contains two or more constituents which can be easily separated by physical method.
Which of the following interactions would be the strongest?
A. H2O and CH4
B. CH4 and CF4
C. H2O and HBr
D. HBr and CH4
Answer:
i think is c,my ans will not be 100%correct
Which is a compound? A Nitrogen (N) B B. O Neon (Ne) co Oxone (0) D O Amm Ammonia (NH) sc