Chemical properties of water for class 8

Answers

Answer 1

Answer:

pH value is 7neither acidic nor basecan be found in all 3 state (ie. liquid, solid and gas {vapour})it's excellent solvent

Related Questions

The body also loses heat by the evaporation of sweat. How is a tea kettle boiling similar to the evaporation of sweat from the body?

Answers

In both cases, water is being let out of a “container” due to heat

Answer:

Our body loses heat by the evaporation of sweat, which is like a tea kettle boiling on a stove top. Both are being heated through conduction, the tea kettle from the stove top and the sweat from our body.

Explanation:

Hope this helps!

Filling Air Bags Automobile air bags produce nitrogen gas from the reaction:


a. If 2.25 g of NaN3 reacts to fill an air bag, how much P–V work will the N2 do against an external pressure of 1.00 atm given that the density of nitrogen is 1.165 g/L at 20°C?


b. If the process releases 2.34 kJ of heat, what is ∆E for the system?

Answers

(a) The work done by the nitrogen against external pressure is 126.66 J.

(b) The change in the internal energy of the system is -2,466.66 J.

The given parameters:

Mass of the compound, = 2.25 gExternal pressure, P = 1.0 atm = 101325 PaDensity of Nitrogen gas, ρ = 1.165 g/LTemperature of the Nitrogen gas, T = 20⁰C

The molar mass of the given compound is calculated as follows;

NaN₃ = 23+ (14 x 3) = 65 g/mol

65 g -------------- 42

2.25 g ------------- ?

[tex]= \frac{2.25 \times 42}{65} \\\\= 1.45 \ g[/tex]

The volume of the nitrogen gas is calculated as follows;

[tex]\rho = \frac{m}{V} \\\\V = \frac{m}{\rho} \\\\V = \frac{1.45}{1.165} \\\\V = 1.25 \ L[/tex]

[tex]V = 0.00125 \ m^3[/tex]

The work done by the nitrogen against external pressure is calculated as follows;

[tex]W = PV\\\\W = 101325 \times 0.00125\\\\W = 126.66 \ J[/tex]

The change in the internal energy of the system is calculated by applying first law of thermodynamics as follows;

[tex]\Delta E = Q - W\\\\\Delta E = (-2,340) - (126.66)\\\\\Delta E = -2,466.66 \ J[/tex]

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I'm melting point of a substance is the blank which it melts

Answers

Answer:

hope its help

Explanation:

melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1

Answer:

I hope you have your correct answer

Explain what is wrong with this electron dot diagram for the element nitrogen

Answers

Hello, is there anyone here a pharmacy technician?

What is a element
2. compound
3.molecules

Answers

Answer:

what is Element: each of more than one hundred substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e. the number of protons in the nuclei of its atoms.

Explanation:

2. compound:a thing that is composed of two or more separate elements; a mixture.

3. Molecules: A molecule is an electrically neutral group of two or more atoms held together by chemical bonds. Molecules are distinguished from ions by their lack of electrical charge

For a constant force, when the surface area is tripled the

.

— Pressure =

force

surface area

pressure is

(a) doubled.

(b) a third as much.

(c) tripled.

(d) unchanged.

Answers

I think it is c

because it say tripled

which of the following statements about this reaction is true:
CH4+2O2-->CO2+2H2O+Heat
A. The reaction releases heat.
B. heat is absorbed by the reaction.
C. the reaction consumes water.
D.The reaction releases oxygen.

Explanation:?

Answers

[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪  {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]

The Correct statement is ~

A. The reaction releases heat

As we can observe, there's heat in product side of the given equation that shows - In the given reaction heat is released making it an exothermic reaction ~

I hope it helps ¡

[tex]\mathrm{✌TeeNForeveR✌}[/tex]

According to Newton's law of universal gravitation, how are mass and
gravitational force related?
A. Mass and gravitational force are the same.
B. An increase in mass is a decrease in force.
C. An increase in mass is an increase in force.
O D. Mass and gravitational force are not related.

Answers

Explanation:

Since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. So as the mass of either object increases, the force of gravitational attraction between them also increases.

Methods used to separate heterogeneous mixtures include the following: check all that apply. *

Decanting
Filtration
Sifting

Answers

Answer:

Filtration, Sifting and Decanting

Explanation:

Heterogenous mixtures can be seperated by filtration and sifting (Also known as sieving). Sifting is the process of parting a mixture using a sieve. Sifting is used to separate solid mixtures that contain molecules of varying sizes. Filtration is the process of separating a liquid from an insoluble solid. A common example is using a funnel and a coffee filiter to seperate the liquide from the insoluable solid. Although there are many other methods for filtration. You can also separate mixtures by decantation. Decantation is the process of separating a liquid from a solid/liquid by removing the liquid layer at the top from the layer of solid/liquid below.

Why was einstein not happy with the probable positions of electrons in the orbitals?

Answers

Since electron orbitals are described as probability clouds, Einstein disagreement with the probable positions of electrons in the orbitals is that, It is not possible to know the orbit of an electron when the position is under probability.

According to Bohr's theory, it is difficult to locate electron or cannot be located in a definite region. Electron has to be found in an orbit and nowhere else. When the probability of finding an electron in a given spherical shell around the nucleus is plotted the distance of the electron from the nucleus for the hydrogen atom, the graph indicates that the probability of finding the electron increases as the distance between the electron and the nucleus decreases

Bohr claimed that electrons a entities had only probabilities if they weren't observed. While Einstein argued that they had independent reality.

But in wave mechanics Model, there is a slight chance of knowing the location of the electron.

Heisenberg uncertainty principle also claim the possibility of knowing the position of electron. Albert Einstein also claim that; to determine the position of an electron to an accurate extent, you would have to compromise your ability to know it's momentum. This inaccuracy will eventually affect the measurement of momentum which will be extremely uncertain.

Since electron orbitals are described as probability clouds, Einstein disagreement with the probable positions of electrons in the orbitals is that, It is not possible to know the orbit of an electron when the position is under probability.

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Which of the following are required for plants to carry out photosynthesis?
Group of answer choices

soil

water

carbon dioxide

oxygen

sunlight

Answers

Answer:

Carbon dioxide, water, and sunlight

Explanation:

help asap for brainlist

Answers

The answer is option three (3)

7. What is the name of the compound AICO3?

Answers

Answer:

Calcium carbonate

Explanation:

Hope this helps :)

Have an amazing day <3

It is Aluminum Carbonate

C2H4NH Lewis structure

Answers

if it’s just C2H4 it’ll be

Li+1 is an ion of Lithium with an overall +1 charge. It has 3 protons. How many electrons does it have?

Answers

Answer:

2 electrons.

Explanation:

what is the coefficient for 4K2CO3

Answers

It should be K= 8 C= 4 O= 12.

If an iron nail was placed in the copper sulfate solution, would you see a
change?
Explain your answer.

Answers

Answer:

Iron displaces copper ions

Explanation:

which means that iron in more reactive than copper.

(Fe2+) and cupric ion (Cu2 +) is converted into metallic copper. Fe (s) + Cu2 + (aq) —→ Fe2+ (aq) + Cu (s).

What is an element? Arrow

Answers

Answer:

One arrow is positioned in each box according to Hund's Rule which tells us to maximise the number of unpaired electrons in orbitals of the same subshell, and, to give those electrons the same "spin" (parallel spin).

Explanation:

Chemistry help!!

A student conducts an experiment to separate water into hydrogen and oxygen as shown below.

As a result the student collects 28.0 g of hydrogen and 224.0 g of oxygen. How many grams water did the student originally have involved in the experiment

Answers

The student originally has 252 grams of water in this experiment.

LAW OF CONSERVATION OF MASS:

The law of conservation of mass explains that matter (mass) can neither be created nor destroyed but can be changed from one form to another.

This means that in a chemical reaction, the sum of the masses of the reactants must equate to the total mass of product(s).

According to this question, a student conducts an experiment to separate water into hydrogen and oxygen. The student collects 28.0 g of hydrogen and 224.0 g of oxygen.

Since hydrogen and oxygen are the constituent elements of water, the sum of their masses must equate the mass of water.

Therefore, 224g of oxygen + 28g of hydrogen = 252g of water.

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Why doesn’t one-electron transfer from a hydrogen atom to another hydrogen atom?

Answers

Answer:

The electrons start to repel each other.

Explanation:

Most atoms attain a lower potential energy when they are bonded to other atoms than when they are separated. One is that the single electrons that each hydrogen atom possesses begin to repel each other. This repulsive force would tend to make the potential energy of the system increase.

A disadvantage of disposing of waste polymers through _____ is that they must first be separated, which can be expensive. What is the missing word in this sentence?

Answers

A disadvantage of disposing of waste polymers through recycling is that

they must first be separated.

Recycling is the process of forming new polymers and compounds as against their disposal .

Recycling involves separating the items into various sections such as paper,

plastic , metal etc. This is because they both undergo different recycling

processes.

The disadvantage of this process is that it's time consuming and also

expensive as a great amount of time and man power is needed to

separate the waste items.

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What is an example of a polar molecule

Question 8 options:

A molecule that is made of ionic bonds like NaCl.


A molecule that is made of covalent bonds like sugar.


A molecule made of covalent bonds that has partial positive and partial negative charges in different areas of the atom.


A molecule made of ionic bonds that has strong positive and strong negative charges in different areas of the molecule.

Answers

Answer:

The two main classes of molecules are polar molecules and nonpolar molecules. Some molecules are clearly polar or nonpolar, while others fall somewhere on the spectrum between two classes. Here's a look at what polar and nonpolar mean, how to predict whether a molecule will be one or the other, and examples of representative compounds.

Explanation:

so its c

An example of polar molecule is a molecule made of covalent bonds that has partial positive and partial negative charges in different areas of the atom.

What is covalent bond?

Covalent bond is defined as a type of bond which is formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.

Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent bonding involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.

Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.

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measuring the isotopic composition of atmospheric co2 shows that the burning of fossil fuels has led to _____ co2 levels over the last 200 years.

Answers

Answer:

measuring the isotopic composition of atmospheric co2 shows that the burning of fossil fuels has led to the co2 levels over the last 200 years.

Explanation:

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PLS HELP: Endocrine Organs Crossword

Answers

the answer to 4 down is Adrenal

What three factors describe the
movement of surface water in streams and
rivers?

Answers

Three factors that describe the movement of surface water in streams and rivers are the river's gradient, flow, and stream load.

I hope this helps!







Q. What phase change occurs at letter A?

Answers

Answer:

Where is the picture? Can't answer without it.

Which of the following describes how photochemical smog is bad for the environment?
1. Decreases crop yields
II. Interferes with amount of sunlight reaching plants
III. Mixes with moisture and becomes acidic
OI and 11
Oll and III
O I and III
O I, II, and III

Answers

Answer:

Its l and ll

Explanation:

it doesn't mix with moisture that would be sulfurous smog

Answer: 1 and 3

qwq rawr

Write the balanced chemical equation for the reaction
of solid carbon with oxygen gas to form carbon monoxide gas.

Answers

Answer:

2C +O2 - CO

Explanation:

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The balanced chemical equation for the reaction of solid carbon with oxygen gas to form carbon monoxide gas is  2 C + O₂[tex]\rightarrow[/tex] 2 CO.

What is chemical equation?

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.

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A car starts from rest and accelerates at 2.5m/s^2 for 2s. What is the final velocity of the car

Answers

Question :-

A car starts from rest and accelerates at 2.5m/s² for 2s. What is the final velocity of the car?

Required Solution :-

The final velocity of the car is 5 m/s

Provided that :-

Acceleration, a = 2.5m/s²Time taken, t = 2 secInitial velocity, u = 0 m/s (As car started from rest)

To Calculate :-

The final velocity of the car

Required Equations of Motion :-

[tex]\begin{gathered}\boxed{\begin{array}{c}\\ {\pmb{\sf{Three \: equation \: of \: motion}}} \\ \\ \sf \star \: v \: = u \: + at \\ \\ \sf \star \: s \: = ut + \: \dfrac{1}{2} \: at^2 \\ \\ \sf \star \: v^2 - u^2 \: = 2as\end{array}}\end{gathered}[/tex]

Calculation :-

[tex]\pink{\qquad \pmb{ \sf\longrightarrow v \: = u \: + at}}[/tex]

[tex] \qquad \pmb{\sf \longrightarrow v = 0 + 2.5 \times 2}[/tex]

[tex]\qquad \pmb{ \sf\longrightarrow v = 0 + 5}[/tex]

[tex] \qquad \pmb{\sf \longrightarrow v = 5 \: ms^{-1}}[/tex]

[tex]\qquad \longrightarrow {\pink{\underline{\underline{\pmb{\sf{ Final \: velocity= 5 \: ms^{-1} }}}}}}[/tex]

Henceforth

The final velocity of the car is 5 m/s

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A bar of copper (Copper = 0.385 J/g.°C) and a bar of aluminum (Aluminum = 0.897 J/g.°C) have the same mass. Which requires more energy to increase the temperature from 20°C to 30 °C?

Answers

Answer:

Aluminum

Explanation:

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