please provide is matter about us pure all NCERT questions and answers
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Answer:

1. Sunlight path becoming visible when lots of dust particles are suspended in the air such as light passing through the canopy of a dense forest.

2.When a torch is switched on in a foggy environment, the path of the light becomes visible.

Answer: The mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.

Explanation:

Given: Volume = 450 L

Temperature = 450 K

Pressure = 300 atm

The reaction equation is as follows.

[tex]N_{2} + 3H_{2} \rightarrow 2NH_{3}[/tex]

Here, 1 mole of nitrogen reacts to give 2 moles of ammonia.

From the given data, moles of nitrogen are calculated as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into the above formula as follows.

[tex]PV = nRT\\300 atm \times 450 L = n \times 0.0821 L atm/mol K \times 450 K\\n = \frac{300 atm \times 450 L}{0.0821 L atm/mol K \times 450 K}\\= \frac{135000}{36.945}\\= 3654.08 mol[/tex]

For 3654.08 moles of nitrogen, the moles of ammonia produced is as follows.

[tex]2 \times 3654.08 mol\\= 7308.16 mol[/tex]

Therefore, mass of ammonia (molar mass = 17.03 g/mol) is calculated as follows.

[tex]Moles = \frac{mass}{molarmass}\\7308.16 mol = \frac{mass}{17.03 g/mol}\\mass = 124457.96 g[/tex]

Thus, we can conclude that the mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.

Answer:

1.78 mol

Explanation:

Step 1: Write the balanced equation

CaC₂ + H₂O ⇒ C₂H₂ + CaO

Step 2: Calculate the moles corresponding to 46.3 g of C₂H₂

The molar mass of C₂H₂ is 26.04 g/mol.

46.3 g × 1 mol/26.04 g = 1.78 mol

Step 3: Calculate the moles of H₂O required to form 1.78 moles of C₂H₂.

The molar ratio of H₂O to C₂H₂ is 1:1. The moles of H₂O required are 1/1 × 1.78 mol = 1.78 mol.

Answer:

What element is this. Would you mind inserting a picture or naming the element in the comments section

Answer:

0.723 moles (5 s.f.)

Explanation:

Whenever there is a chemical equation, ensure that it is balanced. This is because a balanced chemical equation tells us the mole ratio (not the ratio of their masses), which means the relationship of the number of moles of reactants or products with one another.

The chemical equation given has already been balanced. Looking at the coefficients of HBr and Ba(OH)₂, the mole ratio of HBr to Ba(OH)₂ is 2: 1.

• 1 mole of Ba(OH)₂ is needed to react with 2 mole of HBr

Find the number of moles of HBr present:

Number of moles= mass ÷mr

Amount of HBr

= 117 ÷(1 +79.9)

= 1.4462 moles (5 s.f.)

Since the amount of Ba(OH)₂ required is half the amount of HBr present,

amount of Ba(OH)₂ required

= 1.4462 ÷2

= 0.723 moles (3 s.f.)

Notes:

• mr

= relative molecular mass

= sum of relative atomic masses (which can be found in the periodic table) in a molecule

Answer:

Burning of fossil fuels

Explanation:

Human activities that increase the amount of carbon dioxide in the atmosphere are;

1) Burning of fossil fuels in industrial and  internal combustion engines

2) Depletion of the available forest cover, due to the consumption of wood as a raw material

3) Farming expansion  that lead to clearing of forests for farming

4) Industrial activities such as the production of cement

5) Deforestation to provide land for development including buildings and infrastructure.

Answer:

Shift it toward the side with lower total mole concentration

Explanation:

The reaction will shift in a direction that is less affected by stress, so that the pressure is reduced. This means that the reaction will change towards where there is fewer gas molecules (the fewer gas molecules, the smaller the pressure).

Answer:

A. Shift it toward the side with lower total mole concentration

Explanation:

Answer:

two valence electrons

Explanation:

Magnesium is alkaline earth metal and belongs to group IIA of the periodic table. It has two valence electrons which are present in 3s subshell.

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Answer:

Magnesium has two valence electrons.

Explanation:

Magnesium is element 12 and belongs to Group 2 of the Periodic Table. An element in Group 2 has two valence electrons.

Here is a video which discusses how to determine the electron configuration of magnesium.

https://youtu.be/AOxaVdA-Sv0

Answer:

Concentric circles

Explanation:

The energy levels are shown as concentric circles around the central nucleus, and the electrons are placed from the inside out. The first two electrons are found in the first energy level, and the third electron is found in the second energy level.

The required temperature of the gas sample is -64.96 °C.

Ideal gas equation gives idea about the behavior of gas at different condition & represented as:

PV = nRT.

From the above equation it is clear that relation between temperature and pressure for this question is:

P₁/T₁ = P₂/T₂, where

P₁ & T₁ are the initial pressure and temperature.

P₂ & T₂ are the final pressure and temperature.

On putting values, we get

T₂ = (145)(-25) / (55.8) = -64.96 °C

Hence required temperature of the sample is -64.96 °C.

To know more about ideal gas equation, visit the below link:
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Answer:

the number of electrons in the cell

Answer:

Im pretty sure its true

Explanation:

Answer:

answer is true .

Explanation:

this may help you

Answer:

Brownian moment means zig-Zag motion of particals Randomly anywhere in the free space or in fluids

Answer:

Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out

Explanation:

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Answer:

The chloride formed when iron reacts with hydrochloric acid is iron (II) chloride, also known as iron dichloride. The reaction between iron and hydrochloric acid is slower than the reaction with zinc, with much smaller hydrogen bubbles produced.

Answer:  

The reaction of iron and hydrochloric acid is slow beacause When dilute Hydrochloric acid is added to iron filings, iron(II) chloride & hydrogen gas is produced. In this reaction iron displaces hydrogen from hydrochloric acid to form iron chloride & hydrogen gas this reaction is a single displacement reaction which reacts slowly.

Explanation:

Answer:

Due to weak oxidizing agent.

Explanation:

In my opinion the results would be affected if using K2Cr2O7/H2SO4 as the oxidizing agent instead of KMnO4 because K2Cr2O7/H2SO4 is weak oxidizing agent as compared to KMnO4. An oxidizing agent is a substance that has the ability to oxidize other substances means that accept their electrons so that's why the results of strong oxidizing agent is different than weak oxidizing agent.

The results of the reaction will be affected due to the difference in :

Oxidizing agent strength

The use of  K₂Cr₂O7 / H₂SO₄ which is weaker oxidizing agent in the reaction will produce a different result from the use of KmnO₄ which is a stronger oxidizing agent.

This is because stronger oxidizing agents in reaction readily accept electrons from reactants while weaker oxidizing agents do not readily accept electrons from substances reacting in the reaction.

Therefore we can conclude that The results of the reaction will be affected due to the difference in oxidizing agent strength

Learn more : https://brainly.com/question/16450420

Although your question is incomplete a general solution is provide within the scope of your question

Explanation:

Activation energy is the minimum amount of energy required for a chemical reaction to take place.

When a chemical reaction occurs then bonds between the reactants break and bonds between the products are formed. This leads to the formation of an activated complex which is also known as transition state.

So, in order to form the activated complex a minimum amount of energy is necessary and this energy is known as activation energy.

Answer:

[tex]\boxed {\boxed {\sf 0.601 \ g \ As}}[/tex]

Explanation:

We want to convert atoms of arsenic to mass in grams. We have to complete 3 steps.

The first step is converting atoms to moles. We use Avogadro's Number for this. This number is 6.022*10²³ and it is the number of representative units (molecules, atoms, etc.) in 1 mole of a substance. In this problem, the particles are atoms of arsenic. So, 1 mole of arsenic contains  6.022*10²³ atoms of arsenic. Use this information to make a ratio.

[tex]\frac{1 \ mol \ As}{{6.022*10^{23} \ atoms \ As} }[/tex]

Multiply by the number of atoms provided in the problem: 4.83 × 10²¹

[tex]4.83 *10^{21} \ atoms \ As *\frac{1 \ mol \ As}{{6.022*10^{23} \ atoms \ As} }[/tex]

The units of atoms of arsenic (atoms As) cancel.

[tex]4.83 *10^{21} *\frac{1 \ mol \ As}{{6.022*10^{23}} }[/tex]

Condense into 1 fraction.

[tex]\frac{4.83 *10^{21} }{{6.022*10^{23}} } \ mol \ As[/tex]

[tex]0.008020591166 \ mol \ As[/tex]

The next step is converting moles to grams. We use the molar mass for this, which is provided. There are 74.92 grams of arsenic in 1 mole of arsenic, so we can make another ratio.

[tex]\frac {74.92 \ g\ As}{ 1 \ mol \ As}[/tex]

Multiply by the number of moles we calculated.

[tex]0.008020591166 \ mol \ As*\frac {74.92 \ g\ As}{ 1 \ mol \ As}[/tex]

The units of moles of arsenic (mol As) cancel.

[tex]0.008020591166 *\frac {74.92 \ g\ As}{ 1}[/tex]

[tex]0.6009026901 \ g \ As[/tex]

The original measurement of atoms (4.83 × 10²¹ ) has 3 significant figures, so our answer must have the same.

For the number we calculated, that is the thousandth place. The 9 in the ten-thousandth place (0.6009026901) tells us to round the 0 to a 1.

[tex]0.601 \ g \ As[/tex]

There are approximately 0.601 grams of arsenic.

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Answer: Here are the answers

Explanation:

7a) Calcium Chloride +water+carbon dioxide

b)Calcium Oxide +Carbon dioxide

8a) zinc + carbon monoxide

b) Aluminum + Carbon dioxide

c) Lead + carbon dioxide

Answer:

What period is the atom in?

1.

What group is the atom in?

What is the name of this atom?

What other atom would have similar

properties to the atom?

Will this atom conduct electricity well

Explanation:

How many of each kind of atom is in one molecule of water? 1 hydrogen atom and 2 oxygen atoms 1 hydrogen atom and 1 oxygen atom 2 hydrogen atoms and 1 oxygen atom 2 hydrogen

and 2 oxygen atoms

Answer:

Liquid

Explanation:

Quite an easy question!

Answer:

Liquid

Explanation:

I was passing by lol

Answer: The mass of NaCl required to make 140 grams of a 12% solution of NaCl in water is 17 g.

Explanation:

Given: Mass of solution = 140 g

Mass percent = 12%

Formula used to calculate grams of solute are as follows.

[tex]Grams of solute = \frac{grams of solution \times mass percent}{100 percent}[/tex]

Substitute the values into above formula as follows.

[tex]Grams of solute = \frac{grams of solution \times mass percent}{100 percent}\\= \frac{140 g \times 12 percent}{100 percent}\\= 16.8 g\\= 17 g[/tex]

Thus, we can conclude that the mass of NaCl required to make 140 grams of a 12% solution of NaCl in water is 17 g.

Considering the definition of percentage by mass, the correct answer is the third option: 17 grams of NaCl is required to make 140 grams of a 12% solution of NaCl in water.  

The Percentage Composition is a measure of the amount of mass that an element occupies in a compound and indicates the percentage by mass of each element that is part of a compound.

This is, the percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.

In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.

The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:

[tex]percentage by mass=\frac{mass of solute}{mass of solution}x100[/tex]

In this case, you know:

Replacing:

[tex]12=\frac{mass of solute}{140 grams}x100[/tex]

Solving:

mass of solute= [tex]\frac{12 x 140 grams}{100}[/tex]

mass of solute= 16.8 grams ≅ 17 grams

Finally, the correct answer is the third option: 17 grams of NaCl is required to make 140 grams of a 12% solution of NaCl in water.

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