Answer:
I say the 1st one I'm so terrible sorry if I'm wrong
Explanation:
Water can take many forms. At low temperatures (below 0°C), it is a solid. When at “normal” temperatures (between 0°C and 100°C), it is a liquid. While at temperatures above 100°C, water is a gas (steam).
The state the water is in depends upon the temperature. Each state (solid, liquid, and gas) has its own unique set of physical properties.
Calculate AH for the following reaction.
C2H4(g) + H2(g) → C2H6(g)
(ΔHf° for C2H4(g) = 52.5 kJ/mol; ΔHf° for C2H6(g) = -84.7 kJ/mol)
a. -137.2 kJ
b. -32.2 kJ
c. 32.2 kJ
d. 137.2 kJ
Answer:
a.-137.2 kJ
Explanation:
If the first example symbol used is addition you can copy the plus and follow it how to solve the next!And also if the negative or positive sign.
what is 412.12 reduced to two significant figures?
Answer: 410
Explanation:
Drop the retaining numbers 1 and 2 after the decimal and then round the 2 in 412 to 0 because any number less than 5 rounds to 0. 0 shouldn’t count as a sig fig.
-HELP-
How many molecules are contained in 125 grams of oxygen gas (O2)?
Answer:
62.50
Explanation:
I divided the 125 in the result is 62.50 but it is considered a 62.
never mine:)
[tex]125gms[/tex] of oxygen gas contains [tex]2.35\times 10^{24}[/tex] molecules of oxygen.
The molecular weight of oxygen[tex]=16[/tex]
Therefore,[tex]O_2=2\times 16\\=32[/tex]
No.of Moles of oxygen in 125g is,
[tex]\frac{125}{32}=3.9 g[/tex]
1mole of oxygen contains [tex]6.023\times10^23 molecules[/tex]
No.of oxygen molecules in 3.9 g of oxygen is,
[tex]3.9 \times 6.023 \times10^23=2.348 \times 10^24[/tex]
Which can be roundoff and written as [tex]2.35 \times10^{24}[/tex]
Therefore, 125gms of oxygen gas contains [tex]2.35 \times10^{24}[/tex] molecules of oxygen.
Learn More: https://brainly.com/question/25261193
what is the generic equation for a combustion reaction?
Answer:
The generic equation for a combustion reaction is AB + O2 à AO + BO
Explanation:
An unknown substance with a mass of 83 grams absorbs 1,108 J while undergoing a
temperature increase of 11 °C. What is the specific heat of the substance?
Look at picture
ASAP please will mark as brainlist don’t got much time
Answer:
The specific heat of the substance is 1.21 [tex]\frac{J}{g*C}[/tex]
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
There is a direct proportional relationship between heat and temperature. The constant of proportionality depends on the substance that constitutes the body as on its mass, and is the product of the specific heat by the mass of the body. So, the equation that allows calculating heat exchanges is:
Q = c*m*ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
In this case:
Q=1108 J c= ? m= 83 g ΔT= 11 CReplacing:
1108 J= c*83 g* 11 C
Solving:
[tex]c=\frac{1108 J}{83 g* 11 C}[/tex]
c= 1.21 [tex]\frac{J}{g*C}[/tex]
The specific heat of the substance is 1.21 [tex]\frac{J}{g*C}[/tex]
why do animals need carbohydrates in their diets
Answer:
Carbohydrates are energy-providing feed components composed of carbon, hydrogen, and oxygen. They should make up about 75 percent of an animal's diet. The energy they provide powers muscular movements. Carbohydrates also produce the body heat that helps keep the animal warm.
What are the three components of soil texture?
Hurry please help!
Answer: sand, silt, and clay.
What is an energy
transformation?
A. When energy is destroyed
B. When energy changes from one form to
another
C. When energy is created
D. When energy is lost
bron
Answer:
B. When energy changes form one to another.
Explanation:
Energy transformation, also known as energy conversion, is the process of changing energy from one form to another. In physics, energy is a quantity that provides the capacity to perform work or provides heat.
Why is overuse of resources a problem ?????
Answer: the overuse of resources will lead to a decline of the resources, the question was a little non specific so this was the best I could do :)
Explanation:
Which PAIRS below are PHASE CHANGES that occur at the same temperature? (Choose the 2 correct statements.) *
Freezing and Condensation
Freezing and Melting
Vaporization and Condensation
Melting and Vaporization
Answer:
I would say C and D
Explanation:
Hope this helps my good friend :)
According to the forces of attraction, the phase changes that occur at the same temperature are vaporization and condensation, melting and vaporization .
What are forces of attraction?Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
Learn more about forces of attraction,here:
https://brainly.com/question/23841038
#SPJ6
A student is studying the ways different elements are similar to one another. Diagrams of atoms from four different elements are shown below. Nucleus Nucleus Atom 1 Atom 2 Nucleus Nucleus Atom 3 Atom 4
Answer:
atom 1 and atom 2
Explanation:
A more reactive metal displaces a less reactive metal from salt solution. Such reactions are called:
Answer:
Displacement Reaction.
Answer:
displacement reaction
Question 1 of 10
What do biologists study?
A. Living things
B. The properties of light
C. The properties of matter
D. How matter and energy interact
SUBMIT
Answer:
A
Explanation:
Biology is the study of living things.
What is the average speed of 3043 km from houston to seattle in 5.5 hours rounded to the nearest hundredth
Answer:
The average speed is 553.27[tex]\frac{km}{hour}[/tex]
Explanation:
Speed is the physical magnitude that shows and expresses the variation in position of an object and as a function of time. In other words, the speed relates the distance traveled by an object in the unit of time.
The average speed is the quotient of the space traveled by an object and the time it takes to cover the path:
[tex]speed=\frac{distance}{time}[/tex]
In this case:
distance: 3,043 kmtime: 5.5 hoursSo, replacing in the definition of speed:
[tex]speed=\frac{3,043 km}{5.5 hours}[/tex]
Solving:
speed= 553.27[tex]\frac{km}{hour}[/tex]
The average speed is 553.27[tex]\frac{km}{hour}[/tex]
5. How would the food web in Figure 7 change if the numbers of red foxes were
greatly reduced by hunters?
Help meee
Answer:
I cant help you because you didn't provide a picture for the graph
Explanation:
Which of the following is not a part of the digestive system
A. Mouth
B.Esophagus
C.Intestines
D.Kidneys
Answer:
Kidneys •_•
Hope this helped <3
HELP ASAP!
Which type of molecule provides cells with energy?
Carbohydrate
Nucleic acid
Protein
Water
Answer:
ATP
Explanation:
ATP is the most abundant energy carrier molecule in cells.
basically nucleic acid
Heeeeeellllppp, Iiiimmm sssooo stttuuuccckkk!
Answer:
I think it would be D. None of the above
Explanation:
why I think this is because none of the answers really adds up to it
what refers to the effect of gravity
on an
object?
A. mass
B. matter
thing
C. volume
D. weight
Answer: D
Explanation:
Weight by definition is mass multiplied by the acceleration of gravity. So, weight is the force of gravity
what is an example of a problem that could be solved by applying knowledge of the behavior of light
Answer:
The application of reflection in the use of the microscopes.
Explanation:
Reflection is one of the properties of light. Reflection is a phenomenon whereby light waves hitting a surface is bounced off. Reflection helps us to see light and colors. This behavior of light is harnessed in the design of the microscope.
The light reflected by the microscope helps the researcher to view the specimen in his slide. Also, the mirrors placed in measuring devices reflects light that helps an observer to take an accurate reading.
What is the concentration of a salt water solution with 15 grams of salt in 100 mL of water?
A. 10%
B. 5%
C. 20%
D. 15%
This problem is providing the mass of salt, 15 g, that is dissolved in 100 mL of water, so its concentration is required and found to be 15 % according to the following calculations:
By mass percent:In chemistry, units of concentration in solutions are used to represent the relative amount of a solute that is dissolved in a solvent. Thus, in this case, we refer to a salt-water solution, whose concentration is calculated via:
[tex]\% m=\frac{m_{salt}}{m_{water}}*100\%[/tex]
In such a way, given the mass of salt, 15 g and volume of water, or solution, 100 mL, one obtains the following:
[tex]\% m=\frac{15g}{100g}*100\% \\\\\% m=15\%[/tex]
Learn more about by mass percent: https://brainly.com/question/5394922
Answer:
D) 15%
Explanation
Is it better for people to learn from others, or is it better for people to learn on their own? {thesis statement} {subject: Writing}
Answer:
on your own?
Explanation:
it sticks better in your head once you fail
im sorry i dont know this i really need points for my maths test
Answer:
It depends on the situation. Most things are better learning from others because others can see what you cant. On the other hand there are some situations were only you can learn from. Take pain as an example. Others can talk about pain as much as they would like but your body dosent know what that feels like unless it feels it on its own and learns from it. An example of learning from others would be smarts such as math, science, history and so forth.
Explanation:
Please help!! And quick 3. Which team will push the box farther?
Team 1 Team 2 5 N
5 N
5 N 5N
12 N
I
Answer:
team 25 N because the force is more
What is Redox reaction? What is oxidized, reduced, oxidizing, and reducing agent?
Answer:
Explained below.
Explanation:
- Redox reaction is defined as any type of chemical reaction whereby the oxidation number of a participating chemical atoms/elements undergo changes.
- The atom that is oxidized is the one that has an increase in it's oxidation number.
- The atom that is reduced is the one that has a decrease in its oxidation number.
- The reducing agent is defined as the atom that is oxidized.
- The oxidizing agent is defined as the atom that is reduced.
Which statements about salt water are true? Check all that apply.
Salt water contains minerals other than salt.
Fresh water is heavier than salt water.
Objects float more easily in oceans than in lakes or rivers.
The temperature of ocean water is affected by the depth of the water.
The temperature of ocean water is affected by the ocean’s location.
Salt water contains minerals other than salt.
The temperature of ocean water is affected by the depth of the water.
The temperature of ocean water is affected by the ocean’s location.
Objects float more easily in oceans than in lakes or rivers.
These are all of the true answers
Answer:
First one and the last three
Explanation:
hope it helps
Please answer this question ASAP
Salts of metals can be prepared by reacting a metal with an acid to produce the
salt and the gas hydrogen. Describe the test to show that the gas is hydrogen.
(2 marks)
Answer:
put a test tube over the opening, remove it and quickly put a lit splint near the mout or in the tube. if you hear a squeaky pop it is hydrogen.
Explanation:
hydrogen ignites in air.
10pts! Will give brainllest! But please make sure your answer is correct.
Which of the following is true about weight and mass?
A.Your weight and mass are the same
B.Your mass would be more on Jupiter because it has more gravitational force.
C.Your weight would be greater on Jupiter because it has more gravitational force.
D.Your weight would be greater on the moon because it has more gravitational force.
Answer:
B. your mass would be more on jupiter because it has more gravitational force.
Explanation:
good luck must be a test
cell are the blank unit of all living organisms
Something that helps us to understand things that are too large or too small are called A. atoms B. molecules C. models D . compounds
____________ acceleration involves speeding up, while ____________ acceleration involves slowing down. a. positive, negative c. positive, braking b. negative, positive d. both a and c
Answer:
Positive acceleration involves speeding up, while negative acceleration involves slowing down.
Explanation:
I am so sorry if I was wrong!
Answer:
no just no
Explanation: