Answer: d) -705.55 kJ
Explanation:
Heat of reaction is the change of enthalpy during a chemical reaction with all substances in their standard states.
[tex]2CO_2(g)+2H_2O(l)\rightarrow C_2H_4(g)+3O_2(g)[/tex] [tex]\Delta H=+1411.1kJ[/tex]
Reversing the reaction, changes the sign of [tex]\Delta H[/tex]
[tex]C_2H_4(g)+3O_2(g)\rightarrow 2CO_2(g)+2H_2O(l)[/tex]
[tex]\Delta H=-1411.1kJ[/tex]
On multiplying the reaction by [tex]\frac{1}{2}[/tex] , enthalpy gets half:
[tex]0.5C_2H_4(g)+1.5O_2(g)\rightarrow CO_2(g)+H_2O(l)[/tex][tex]\Delta H=\frac{1}{2}\times -1411.1kJ=-705.55kJ/mol[/tex]
Thus the enthalpy change for the given reaction is -705.55kJ
when do meanders form in a river?
A.young
B.old
C.mature
D.rejuvenated
Answer:
The formation of a meander. As the river erodes laterally, to the right side then the left side, it forms large bends, and then horseshoe-like loops called meanders . The formation of meanders is due to both deposition and erosion and meanders gradually migrate downstream.
A sample contain 33.42g of metal pellets are poured on to a graduated cylinder initially containing 12.7ml of water, causing the water level to rise to 21.6ml. Calculate the density of the metal
Answer:
3. 76 g/ml^3
Explanation:
We are given the mass of the metal pellets which is 33.4 grams. To calculate the density of the metal, we need to divide the mass by the volume. The volume of the metal is not directly given so we need to find it ourselves. The water was initially 12.7 ml and then it rose to 21.6 ml after placing the metal pellets. This indicate that the volume of the metal pellets is 8.9 ml.
[tex]21.6 - 12.7 = 8.9[/tex]
We can now use the density formula.
[tex]p = \frac{m}{v} [/tex]
[tex]p = \frac{33.42}{8.9} [/tex]
[tex]p = 3.76[/tex]
The density of the metal is equal to 3.76 g/ml.
What is the density?The density of an object can be defined as the mass per unit volume. The average density is equal to the total mass of the object divided by the total volume of the object.
The mathematical formula for the density of the material is expressed as follows:
Density = Mass/Volume
The S.I. unit of the density is Kg/m³ and is an intrinsic property as it is independent of the size. If the size increases, the mass increases as well but the density of the material remains constant.
Given the mass of the metal, m = 33.42 g
Volume of the metal = Volume of water level with metal - volume of water
V = 21.6 -12.7 = 8.9 ml
The density of metal = 33.42/8.9 = 3.76 g/ml
Therefore, the density of the metal is 3.76 g/ml
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Which describes the elements in a given group of the periodic table?
They decrease in atomic mass as you go down the column.
They increase sequentially in atomic number from top to bottom.
They are in the same family, with similar characteristics.
Their properties change according to a pattern as you go down the column.
Answer:
They are in the same family, with similar characteristics.
Explanation:
The elements in a given group of the periodic table are in the same family and with similar characteristics.
Vertical columns on the periodic table are referred to as a group or family. Elements having the same number of electrons in the outermost shell of their atoms are placed one another in vertical columns. Each resulting vertical column is a group or family. Elements in the same group exhibit similar chemical properties because of the same number of electrons in their atoms' valence shells.ANSWER ASAP PLEASE!!
What determines how many of each ion is required for an ionic compounds?
please do not look up on google!!!!
Each ion has a single charge, one positive and one negative, so we need only one ion of each to balance the overall charge. When writing the ionic formula, we follow two additional conventions: (1) write the formula for the cation first and the formula for the anion next, but (2) do not write the charges on the ions.
PLS ANSWER!! ASAP!!! 10 POINTS!!
Why are metals in Group 1A so reactive?
A. These metals need one electron to complete their outer shell.
B. These metals need two electrons to complete their outer shell.
C. These metals have one electron in their outer shell.
D. These metals have two electrons in their outer shell.
Answer:
the answer is = a. these materials...
The metals of Group 1A are so reactive because these metals have one electron in their outer shell. Therefore, option (C) is correct.
What are the metals of Group 1A?The elements of Group 1A of the periodic table are also called alkali metals. The seven elements of group 1 A include hydrogen(H), lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
These are low-melting, extremely reactive, glossy metals that oxidize when exposed to air. When dissolved in water, these metals or their oxides produce a basic solution. Because of their high reactivity, alkali metals are instead found as ionic compounds (except hydrogen).
The general electronic configuration of the alkali metals is ns¹. As they lose one electron from their valence shell they acquire the nearest noble gas configuration, therefore they are very reactive.
The alkali metals are all lustrous, soft, and extremely reactive metals at normal temperature and pressure that quickly lose their valence electrons to create cations with charge +1.
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how are sol, solution and suspension different from each other?
plzzzzzz answer asap
Answer:
a
Explanation:
This picture shows a model if a cell. What is the main function of the part labeled Z in the model?
Answer:
store water so b
Explanation:
labeled Z in the model refers to store food and other material in the cell.
what is cell?
cell can be defined as the basic unit of the living cell, it can be unicellular or multicellular. unicellular organism are prokaryote and some of the unicellular eukaryotes whereas multicellular organisms are eukaryotes like plants and animals.
a basic component of cell are cell membrane, cytoplasm, nucleus, mitochondria, lysosome, golgi body, endoplasmic reticulum.
cell wall only present in plant cell and prokaryotic cell while it is absent in animal cell, the function of cell wall is to provide protection
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You have a solution of water and pure ethanol. The boiling point of water is 100 degrees Celsius and the boiling point of pure ethanol is 78 degrees Celsius. A. What process would you would use to separate this solution? Describe, in detail, how this process works.
Answer:
Distillation
Explanation:
A solution of water and ethanol are miscible. Hence, they can only be separated by a process known as distillation. Distillation is the process in which two or more constituents in a mixture are separated based on there difference in boiling points. The mixture is subjected to high heat and the one with the least boiling point distills/evaporates out first followed by the next least boiling point.
From the explanation above, it can be deduced that ethanol (with boiling point of 78°) will be distilled out while water remains in the boiling tube or container.
Carbon is considered an element, while carbon dioxide is considered a compound. This is because carbon dioxide is
Answer: This is because carbone dioxyde is composed of more than just an atom of carbon , it’s composed of 2 atoms of oxygen and one atom of carbon .
* I hope it was helpful , good luck :) *
Answer question number 6
In which region is the substance in both the solid phase and the liquid phase?
1 2 3 4
Answer:
its 2 on ed I promise do not listen to the brainiest
Explanation:
Answer:
B)2
Explanation:
According to the law of conversion of mass in a chemical equation
Please help brainiest
Answer:
D.) Formulas l, ll, and lV
Explanation:
Formula l, ll, and lV all have 2 oxygen atoms. Formula lll have 4 oxygen atoms and forumula V has 6 oxygen atoms.
electron configuration of silver
Answer:
[Kr] 4d10 5s1 or 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s1
3. Which of the following does not affect the solubility of solid solutes?
a. Volume of solvent
b. Stirring
c. Temperature
d. Amount of solvent
Answer:
Temperature
Explanation:
i GUESS that's the ans lol sry I needed points
What is Arsenic cost per unit?
Answer:
arsenic costs $320 per 100g
Explanation:
The number of electrons in the outermost shell of nitrogen atom
Answer:
5
Explanation:
Which of the following is an example of very early scientific research?
sleeping in caves to avoid predation by animals
painting pictures and symbols on cave walls
making baskets from reeds
banging rocks together to see which make a spark and create fire
Answer:
banging rocks together to see which make make a spark and create fire painting pictures is an example of art and sleeping in caves is survival
What is the main cause of any change of state?
Answer:
During a change in state, the motion of the particles changes. ... Particles in a liquid can side past each other, but particles in a solid can only move enough to vibrate. Removing energy from a liquid can cause it to change to a solid. Adding energy to a solid can cause it to change to a liquid.
Hope this helps! please give me brainliest!
God bless:)
Change of state is caused by supply of heat to a substance causing its molecules to move faster.
There are three states of matter, these are;
SolidLiquid GasIt is possible for a substance to be transformed from one state of matter to the other when heat energy is supplied to the substance.
This heat energy causes the kinetic energy of the molecules of the substance to increase hence they vibrate faster and change from one physical state to another.
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What is the correct value using 3 significant figures for 14.8232 g/mol?
Answer:
14.8 g/mol
Explanation:
Starting on the left, count in 3 numbers (14.8), then round using the next number (0.02).
Because 2 is less than 5, the number stays the same and is not rounded up.
Which of the following statements is correct about the shape of the H2O molecule? Select all that apply.
Water is a linear molecule with bond angles of 180o
Water is a bent molecule with bond angles of 104.5o
Water has two pairs of unbonded electrons which are spread out evenly between the hydrogen atoms
Water’s two pairs of unbonded electrons push the hydrogen atoms further away from their negative charge
Answer:
Water is a bent molecule with bond angles of 104.5o
Water has two pairs of unbonded electrons which are spread out evenly between the hydrogen atoms
Explanation:
Water is a substance with chemical formula, H2O i.e. two hydrogen atoms bonded to one hydrogen atom. The more electronegative oxygen atom draws electron from the less electronegative hydrogen atoms to make the molecule a POLAR ONE. The water molecule assumes a bent shape with bond angle 104.5°.
The oxygen atom has two lone pairs of electrons, which each hydrogen atom is attracted to. This strong attraction forms hydrogen bonds in the water molecule. Hence, the two pairs of unbonded electrons in the water molecule are spread out evenly between the hydrogen atoms.
Students were investigating properties of matter, but wanted to make sure that when they tested these properties they had properties that would represent the matter they were testing specifically. The students claim that they are going to test intrinsic properties. What evidence and reasoning would you provide to justify this claim? (7 points)
Answer:
See explanation
Explanation:
An intrinsic property is a property that is internal, that is, it characterizes the substance under study. The possession of an intrinsic property depends on the nature of the substance. An intrinsic property does not depend on amount of substance but on the nature of the substance.
Examples of intrinsic properties include; Density. Solubility, Melting Point, Freezing Point, Boiling Point, Conductivity etc.
Intrinsic properties really represent the matter that is being studied. For instance, the boiling point of water will always be 100°c. No other liquid can boil exactly at that temperature. Hence, this intrinsic property can always be used to identify an unknown liquid as water.
The students were right, studying intrinsic properties accurately represent the matter that is being studied.
I need help again LOL.
Answer:
They require diffrent types of atoms for their makeup I belive is the answer Hope this helps
Explanation: Wow you have a lot a questions XD :D :3
Element: A substance that is made up of only one type of atom. Compound: A substance that is made up of more than one type of atom bonded together. Mixture: A combination of two or more elements or compounds which have not reacted to bond together; each part in the mixture retains its own properties.
i hope this helps
HELP ASAPP JUST TELL ME WHAT TO PUT IN THE MISSING SPACES words(cell,microorganisms,micrometer,microscopic,molecule)
Answer:
microorganisms, molecule, microscopic, cell, micrometer
Explanation:
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Coffee is an example of a
a
homogeneous mixture
b
heterogeneous mixture
c
suspension
d
colloid
Answer:
A
Explanation:
Calculate the number of molecules of sulphur S8 in 8 gram of solid Sulphur
Answer:
12gram
Explanation:
test told me
how many atoms are in CaCI2
Answer:
4
Explanation:
bc Ca is 1 C is one L is two
What does the “188” represent in Tantalum-188
A. mass number
B. atomic number
C. mass defect
Answer:
mass number
Explanation:
When there is an element name followed by a dash and then a number, the number simply represents the mass number.
for example:
Oxygen- 18
18 represents the mass number of this particular isotope
Water can undergo a change of state when its energy changes at specific temperatures. Solid water, or ice, changes into liquid water when its energy increases at its melting point. a. Describe this process. b. Explain how the energy changes with each state.
Answer: The solid turns into liquid during melting.
Explanation:
a. The process of a solid turning into liquid is called melting. The solid ice turns into a liquid during the melting process. The solid molecules gain energy and flow as a liquid.
b. The energy of the molecules increases in the liquid state. When the ice turns into a liquid the energy of the molecules increases. The application of heat or excess temperature increases the energy of the molecules.
Answer question number 3
Answer:
A
Explanation:
A mixture is formed when two or more substances are physically mixed together. A compound is formed when two or more substances are chemically combined through a chemical reaction.