The substances that are present before any chemical reaction are called

Answer:  [tex]AlCl_3[/tex] and [tex]H_2[/tex]

Explanation:

The given balanced chemical equation is :

[tex]2Al+6HCl\rightarrow 3H_2+2AlCl_3[/tex]

In a chemical reaction, the reactants are the substrates which react and are written on the left side of the equation.

The products are the substrates which are formed as a result of the chemical reaction and thus are written on the right side of the equation.

Thus here [tex]AlCl_3[/tex] and [tex]H_2[/tex] are the products.

Final answer:

Earth's atmosphere contained little free oxygen until cyanobacteria’s photosynthesis began producing oxygen, which accumulated over time due to geological activities that limited oxygen's recombination with organic matter. The rise in oxygen levels led to the creation of the ozone layer, allowing life to thrive on land.

Explanation:

Initially, Earth's early atmosphere contained little to no free oxygen. This was because oxygen is a byproduct of photosynthesis, a process that was not prevalent until the evolution of photosynthetic organisms like cyanobacteria. Over time, as more plants appeared and photosynthesis increased, more oxygen was produced. However, the oxygen was quickly removed from the atmosphere through chemical reactions with the Earth's crust, preventing it from accumulating. This changed around 2.4 billion years ago, when geological activity increased and plants were buried before they could decompose fully, which decreased the removal of oxygen and allowed it to begin accumulating in the atmosphere.

The buildup of oxygen in the atmosphere had significant evolutionary consequences. The emergence of the ozone layer, comprised of three oxygen molecules (O3), protected life from the Sun's ultraviolet radiation, enabling the colonization of land. Thus, the oxygenation of the atmosphere facilitated the development of aerobic life and the complex biodiversity we have today.

Answer

1: Hardness

2: Metals

3: Mineral

4: Fossil Fuels

5: Ore

6: Color

7: Streak

8: Mohs Scale

9: Crystal

The student's homework question pertains to the topic of 'Earth Systems and Resources', particularly the study of the properties of minerals. These properties include color, streak, luster, hardness, cleavage, fracture, and specific gravity, among others. An understanding of these properties would likely help in solving the crossword puzzle.

The subject of your crossword puzzle appears to be related to the topic of Earth Systems and Resources, specifically, the Properties of Minerals. Minerals, which are naturally occurring, inorganic substances, are identified by their specific properties. Some of these properties include color, streak, luster, hardness, cleavage, fracture, and specific gravity. For example, a mineral's streak is the color of the powder left when a mineral is scraped against a hard surface. On the other hand, luster refers to how light is reflected from the mineral's surface - it can be shiny (metallic) or dull (non-metallic).

I would recommend referring to your study materials or textbooks to find specific answers to your crossword puzzle. This is because the specific clues or prompts on the crossword puzzle would guide you towards the pertinent terms or facts from this topic.

https://brainly.com/question/25438865

#SPJ3

Answer:

qaaaaaAaaaAAAaaaaaaa

Answer:

Solution A has a lower pH level because it is more acidic. This means that there is a greater amount of hydronium [[tex]H_{3}O[/tex]] present in the solution which results in a more acidic solution.

Answer:

Protons are located in the nucleus and have a positive charge and a mass of 1.

Explanation:

Know about protons, neutrons, and electrons.

The time taken for the completion of a definite fraction of a reaction is an important characteristic for every reaction and its dependence on initial concentration of the reactant is determined by the order of the reaction. Here the number of half lives is 3.

The half life period of a reaction is defined as the time in which the concentration of a reactant is reduced to half of its initial concentration. It can also be called as the time for the conversion of 50% of a reactant into products.

To calculate how many half lives have passed during the formation of pennies, we have to know about the number of heads and tails in the sample. There are a total of 75 heads and 25 tails present in the sample.

So here the sample has been found to pass through 3 half lives.

Thus the number of half lives passed since the sample is formed is 3.

To know more about half life, visit;

https://brainly.com/question/24710827

#SPJ3

Answer:call me 9016914160

Explanation:

Answer:

Explanation:

mass ratio of oxygen and nitrogen in air at Miami

= 21 : 79

ratio of their moles

= [tex]\frac{21}{32} : \frac{79}{28}[/tex]     ( mol weight of oxygen is 32 and of nitrogen is 28 )

=  .65625 : 2.8214

= 1 : 4.3

This ratio will also be maintained in the air of Denver though total pressure decreases there.

Partial pressure of oxygen in air at both the places

mole fraction of oxygen

= [tex]\frac{1}{( 1 +4.3)}[/tex]

= .18868

partial pressure of oxygen at Denver

= .18868 x .83 x 760

= 119 mm.

Denver's total air pressure is 630.8 mm Hg. The percentage of Oxygen in Denver remains the same as at sea level, which is 21%. The partial pressure of Oxygen in Denver is therefore 132.47 mm Hg.

The question is asking us to determine the percentage of oxygen and the partial pressure of oxygen in Denver given that Denver's atmospheric pressure is 83 percent of Miami Beach's pressure. First, let's calculate the total pressure in Denver. We multiply Miami Beach's total air pressure of 760 mm Hg by 0.83 (Denver's air pressure as a fraction of Miami Beach's) to get 630.8 mm Hg as Denver's total air pressure. Since the proportion of oxygen in the air doesn't change with altitude, the percentage of Oxygen remains 21%. Now, let's find the partial pressure of oxygen in Denver. Partial pressure is the pressure that a gas would have if it alone occupied the volume of the mixture. It would be the total pressure times the fraction of the gas in the mixture. So, for oxygen in Denver, the partial pressure would be 630.8 mm Hg * 0.21 (percentage of oxygen in the air) which gives us 132.47 mm Hg.

https://brainly.com/question/30931993

#SPJ12

In a safety contract, important items to include are rules regarding the use of safety equipment, procedures for handling emergencies, and guidelines for reporting unsafe conditions.

When designing a safety contract, it's crucial to include items that promote health and safety. Three items that would be beneficial to include in a safety contract are: Rules regarding the use of safety equipment, Procedures for handling emergencies and Guidelines for reporting unsafe conditions.

Each of these provisions are essential components that strengthen the safety and well-being of all participants involved.

https://brainly.com/question/28428193

#SPJ2

Answer:

C. In ionic bonds one atom accepts electrons from another atom to achieve a stable outer shell.

Explanation: Some Atoms have positive Charges. Like Na (Sodium) has a charge of +1 because its missing an electron, and there are Atoms with a negative charge like Chlorine, it has an extra electron so a charge of -1. The chlorine atom transfers the extra Electron to the sodium atom. they both gain a neutral Charge.

In ionic bonds, one atom accepts electrons from another atom to achieve a stable outer shell. Hence, option C is correct.

An ionic bond is formed by the complete transfer of some electrons from one atom to another.

Some Atoms have positive Charges. Like Na (Sodium) has a charge of +1 because it's missing an electron, and there are atoms with a negative charge like Chlorine, it has an extra electron so a charge of -1.

The chlorine atom transfers the extra electron to the sodium atom. they both gain a neutral Charge.

Hence, option C is correct.

Learn more about ionic bonds here:

brainly.com/question/977324

#SPJ5

Answer:

1.68L

Explanation:

Step 1:

Data obtained from the question. This includes the following:

Initial Molarity (Mi) = 7M

Initial volume (Vi) 0.6L

Final Molarity (Mf) = 2.5M

Final Volume (Vf) =.?

Step 2:

Determination of the final volume of the solution.

This can be achieved as shown below:

MiVi = MfVf

Divide both side by Mf

Vf = MiVi /Mf

Vf = 7 x 0.6 / 2.5

Vf = 1.68L

Therefore, the new volume of the solution is 1.68L

To balance the given equation, the balanced equation is 5[tex]N_2[/tex] + 3[tex]O_2[/tex] → 10[tex]NO_2[/tex]. If 5 moles of [tex]N_2[/tex] reacted, 10 moles of [tex]NO_2[/tex] will be produced. There will be 3 moles of [tex]O_2[/tex] left and 0 moles of [tex]N_2[/tex] left.

To balance the given equation, let's start with nitrogen (N) atoms. There are 2 N atoms on the left side and 2 N atoms on the right side, making it balanced.

Next, let's balance the oxygen (O) atoms. There are 4 O atoms on the left side and 6 O atoms on the right side. To balance it, we need to multiply the [tex]O_2[/tex] on the left side by 3. The balanced equation is:

5[tex]N_2[/tex] + 3[tex]O_2[/tex] → 10[tex]NO_2[/tex]

Now, let's calculate the mole ratio using the coefficients in the balanced equation:

For every 5 moles of [tex]N_2[/tex], we have 10 moles of [tex]NO_2[/tex] produced.

Therefore, if 5 moles of [tex]N_2[/tex] reacted, we will have 10 moles of [tex]NO_2[/tex] produced.

To determine the moles of [tex]O_2[/tex] left, we compare the coefficients of [tex]O_2[/tex] and [tex]NO_2[/tex]. For every 3 moles of [tex]O_2[/tex] consumed, we have 10 moles of [tex]NO_2[/tex] produced. Since only 12 moles of [tex]O_2[/tex] were initially available, 9 moles of [tex]O_2[/tex] will be consumed, leaving 3 moles of [tex]O_2[/tex].

Similarly, to determine the moles of [tex]N_2[/tex] left, we compare the coefficients of [tex]N_2[/tex] and [tex]NO_2[/tex]. For every 5 moles of [tex]N_2[/tex] consumed, we have 10 moles of [tex]NO_2[/tex] produced. Since only 5 moles of [tex]N_2[/tex] were initially available, all of it will be consumed, leaving 0 moles of [tex]N_2[/tex].

Answer:

26.3 mL

Explanation:

Step 1:

Obtaining an appropriate gas law from the ideal gas equation.

This is illustrated below:

From the ideal gas equation:

PV = nRT

Divide both side by T

PV/T = nR

At this stage, we'll assume the number of mole (n) to be constant.

Note: R is the gas constant.

PV/T = constant.

We can thus, write the above equation as:

P1V1/T1 = P2V2/T2

The above equation is called the general gas equation.

Step 2:

Data obtained from the question. This includes the following:

Initial volume (V1) = 27.5 mL

Initial temperature (T1) = 22.0°C = 22.0°C + 273 = 295K

Initial pressure (P1) = 0.974 atm.

Final temperature (T2) = 15.0°C = 15.0°C + 273 = 288K

Final pressure (P2) = 0.993 atm

Final volume (V2) =..?

Step 3:

Determination of the final volume of the gas using the general gas equation obtained. This is illustrated below:

P1V1 /T1 = P2V2/T2

0.974 x 27.5/295 = 0.993 x V2/288

Cross multiply to express in linear.

295x0.993xV2 = 0.974x27.5x288

Divide both side by 295 x 0.993

V2 = (0.974x27.5x288)/(295x0.993)

V2 = 26.3 mL

Therefore, the new volume of the gas is 26.3 mL

Answer:

Ca(aq)⁺²  + CO₃⁻²(aq) → CaCO₃(s)

Explanation:

Breaking down the equation into ionic form gives:

2Na⁺(aq) + CO₃⁻²(aq) + Ca⁺²(aq) + 2NO₃⁻¹ (aq)  →  2Na⁺(aq) + 2NO₃⁻¹(aq)  + CaCO₃(s)

Eliminating all the same ionic states on both sides of the equation gives following final equation

Ca(aq)⁺²  + CO₃⁻²(aq) → CaCO₃(s)

Net ionic equation:-

[tex]Ca^{+2}(aq)+ CO_3^{-2}(aq) \rightarrow CaCO_3(s)[/tex]

Given equation:-

[tex]Na_2CO_3(aq)+Ca(NO_3)_2(aq)\rightarrow2NaNO_3(aq)+CaCO_3(s)[/tex]

Breaking down the equation into ionic form gives:

[tex]2Na^{+} (aq) + CO_3^{-2} (aq) + Ca^{2+}(aq) + 2NO_3^{-}(aq) \rightarrow 2Na^{+} (aq) + 2NO_3^{-} + CaCO_3(s)[/tex]

 Eliminating all the same ionic states on both sides of the equation gives the equation as follows:-

[tex]CO_3^{-2} (aq) + Ca^{2+}(aq) + \rightarrow CaCO_3(s)[/tex]

To know more about:-

brainly.com/question/15467502

Answer:

C. the relative number of atoms of each element, using the lowest whole ratio.

Explanation:

The empirical formula is how we simplify the whole formula to simplify it to its smallest indivisible parts.

It is definitely not the actual number of atoms. If you see an empirical formula, don't think that it's the full thing.

It is also not a representation of a compound to show its atoms' arrangement: this would be a Lewis dot structure, or a ball and stick model, or something similar. We don't use the empirical formula for this purpose.

Answer:

  84 g

Explanation:

The molecular weight of nitrogen is 14.01 g/mol. That of oxygen is 16.00 g/mol, so the weights of the various elements available are ...

From NO

  N: (14.01/(14.01+16.00))·(80 g) = 37.35 g

  O: 80 g -37.35 g = 42.65 g

From O₂

 O: 16 g

__

In each mole of NO₂, the weight of the oxygen is 2(16.00) = 32 g. The weight of the nitrogen is 1(14.01) = 14.01 g.

From the available oxygen, we can produce ...

  (42.65 g +16 g)/(32.00 g/mol) = 1.83 mol of NO₂

From the available nitrogen, we can produce ...

  (37.35 g)/(14.01 g/mol) = 2.67 mol of NO₂

Clearly, the reaction is limited by the amount of available oxygen. Then the mass of the NO₂ that can be produced is ...

  (1.83 mol)(32.00 +14.010 g/mol = 84.3 g ≈ 84 g.

84 grams of NO₂ are produced.

Answer:

See explaination

Explanation:

We have to understand the reason of temperature change , when NaOH reacts with HCl neutralization reaction occurs producing energy. When this released energy is absorbed temperature is increased.

So when 1 mole off NaOH reacts with 1 mole of HCl reacts 57.3 KJ of energy is released .

During a reaction for , when equivalent number of moles reacts higher energy will be produced.

If 80 ml HCl and 20 ml NaOH reacts , then only 20 ml NaOH reacts with 20 ml of HCl and rest 60 ml is not reacting.

But when 60 ml HCl and 40 ml NaOH reacts 40 ml of each are reacting, so energy produced will be higher.

so B > A

For II the observed phenomena is already discussed as higher number of moles of HCl and NaOH reacts so , due to which higher energy is released and thus temperature is higher.

50 ml of each HCl and NaOH produces largest temperature change , as higher number of moles of HCl and NaOH reacts so , due to which higher energy is released and thus temperature is higher.

The Answer To This Question Will Be :

Jose is correct because there is always a force acting upon something. The book is moving by force but you can't see it. Gravity is pulling the book down, but the desk is holding it up. Equal and opposite

Jose is right, as the book is lying on the table, equal and opposite forces are acting on it.

According to Newton's first law, an object can only move when it is acted upon by unbalanced forces. If a body is acted upon by balanced forces, it does not move.

As the book is lying on the table it is acted upon by two equal and opposite forces, of weight and the reaction. Since the forces are equal and opposite, the book does not move.

Learn more:https://brainly.com/question/3715235

The family is most likely to face higher costs for the monthly heating bill by switching to energy from a solar power plant. Although solar power is a renewable and clean energy source, the initial installation and maintenance costs of solar panels can be expensive, resulting in higher monthly bills compared to using natural gas.

Solar power harnesses energy from the sun's radiation to generate electricity or heat. Photovoltaic cells convert sunlight into electricity, while solar thermal systems use sunlight to produce steam for electricity generation or provide direct heating. Solar power is a sustainable and renewable energy source with minimal environmental impact.

The family is most likely to face higher costs for the monthly heating bill by switching to energy from a solar power plant. Although solar power is a renewable and clean energy source, the initial installation and maintenance costs of solar panels can be expensive, which can result in higher monthly bills compared to using natural gas. Additionally, the family may also face limitations in the amount of heat produced as solar power can be dependent on weather conditions.

Option A. Oxygen is the vital element that participates in the carbon, nitrogen, and phosphorus cycles.

The vital element for life that participates in the carbon, nitrogen, and phosphorus cycles is oxygen. Oxygen is necessary for the breakdown of organic matter and the release of carbon, nitrogen, and phosphorus compounds back into the environment. In the carbon cycle, oxygen is involved in the process of cellular respiration and photosynthesis. In the nitrogen cycle, oxygen is necessary for the conversion of nitrogen gas into usable forms by bacteria. In the phosphorus cycle, oxygen is involved in the weathering of rocks and the release of phosphates.

https://brainly.com/question/32262741

#SPJ2

The molality of a solution with 55g of sucrose dissolved in 950mL of water is 0.1692 mol/kg, calculated by dividing the moles of sucrose by the kilograms of water.

To calculate the molality of a solution in which 55g of sucrose are dissolved in 950mL of water, we first need to find the number of moles of sucrose and the mass of the solvent (water) in kilograms.

The molar mass of sucrose (C₁₂H₂₂O₁₁) is approximately 342.3 g/mol. 55 grams of sucrose is therefore 55 g / 342.3 g/mol = 0.1607 mol. Since density of water is approximately 1 g/mL, 950 mL of water weighs 950 g, which is the same as 0.950 kg.

The molality (m) is then calculated using the formula m = mol solute/kg solvent. Substituting the values we have, 0.1607 mol/0.950 kg = 0.1692 mol/kg. So, the molality of the solution is 0.1692 m.

Answer:

0.5 mol.

Explanation:

Given,

Pressure, P = 101.325 kPa = 1 atm

Temperature, T = 0 +273 = 273 K

Volume = 11.2 L

Now, using ideal gas equation

PV = n RT

1 x 11.2 = n x 0.08206 x 273

n = 0.5 mol.

Hence, number of moles of the hydrogen sample of gas at STP is 0.5 mol.

Answer:

protons

Explanation:

Protons is the answer, because they are what determines the identity of an element. Hydrogen always has one proton. No more, no less.

You can remove electrons from an element and it is still the same element. We call it an ion when this happens: think of something like Na+ or Cl-. An electron has been taken or added to those elements, but they're still the same element!

You can remove neutrons from an element and it is still the same element. We call it an isotope when this happens: maybe you've heard of carbon-14, which has two extra neutrons. We use that in carbon-dating. It's still carbon, though!

Those other options, A B and D, are made up of quarks. This isn't the right answer, because you can have two elements with different amount of quarks because quarks make up neutrons and other subatomic particles.

Final answer:

Atoms of an element have the same number of protons, and those with different numbers of neutrons are called isotopes. The mass number (A) is the sum of protons and neutrons in the nucleus. (Option A)

Explanation:

Atoms of an element always have the same number of protons, which is characteristic of that particular element and is known as the atomic number (Z). Atoms that vary in the number of neutrons found within their nuclei are called isotopes. The overall charge of an atom is neutral because it has an equal number of protons and electrons.

Furthermore, the sum of the numbers of protons and neutrons is the mass number, notated as (A). For instance, the carbon atom, which has 6 protons and can have varying numbers of neutrons, is recognized in its standard form as having 6 neutrons, making its mass number (A = 12).

Answer:

Its 11.5 m/s

Explanation:

acceleration =v-u/t

so, 88-42/4 = 46/4 = 11.5 m/s

Answer:

A) is ur answer to the question.

Cuz the bending of rainbow light makes a band spectrum of colours. and the colour that bends the most is Violet.

Hope this helps ya

Answer: C. 121

Explanation:

took the test

The mole concept is used here to determine the grams of the silver metal. The mass of silver metal produced by the reaction of  250.0 grams of 76.0% by mass silver nitrate solution with an excess of copper metal is 121 grams. The correct option is C.

One mole of a substance is defined as that amount of it which contains as many particles or entities as there are atoms in exactly 12 g of carbon-12. One mole of any substance contains Avogadro number of molecules.

Number of moles (n) = Given mass / Molar mass

The equation for the reaction is;

Cu(s) + AgNO3 → Ag(s) + Cu(NO3)2

Mass of silver nitrate = 250.0 g × 0.76 = 190 g

Molar mass of silver nitrate =  169.87 g/mol

Moles of silver nitrate = 190 / 169.87 = 1.118 moles

Mole ratio of Silver nitrate to silver metal = 1 : 1

Therefore, moles of silver metal = 1.118 moles

So the mass of silver metal = 1.118 moles × 107.868 g/mol = 120.59 g ≈ 121 g

Thus the correct option is C.

To know more about mole concept, visit;

https://brainly.com/question/19800462

#SPJ2