Answer number 15 pllllllllssss

Answer:

See Explanation

Explanation:

                     8Fe        +        S₈                =>        8FeS

Given:            10g                  10g

moles      10g/56g/mol     10g/256g/mol

                = 0.179mol Fe   = 0.039mol S₈

Reduce => divide mole values by respective coefficients; smaller value is Limiting Reactant.

                 0.179/8 = 0.022      0.039/1 = 0.039  

       => Fe is limiting reactant

                       8Fe        +               S₈                   =>         8FeS    

Given:     10g/56g/mol          10g/256g/mol

               = 0.179mol              = 0.039 mol                  0.179mol FeS produced

                                          1/8(0.179)mol S₈ used        (coefficients are equal,

                                          = 0.022 mol S₈ used       => moles Fe = moles FeS)

                                         = (0.039 - 0.022)mol S₈     = 0.179mol FeS

                                         remains in excess              =(0.179mol)(88g/mol)

                                         = 0.0166 mol S₈ (excess)  = 15.8 g FeS  

                                         = (0.0166mol)(256g/mol)           (Theoretical Yield)

                                         = 4.26g S₈ in excess

True becuase the substance changed into another substance which is a example of a chemical reaction.

Answer:

A) Charging by contact

Explanation:

Transfer of heat by direct contact, Heat energy is conducted from the hotter medium to the cooler medium

Water is a chemical compound also known as H2O and is composed of two hydrogen atoms (H) and one oxygen atom (O).

2 H2O → 2 H2 + O.

Answer:

When limestone is heated strongly, the calcium carbonate it contains absorbs heat (endothermic ) and decomposes to form calcium oxide. Calcium oxide (also known as quicklime) is a key ingredient in the making of cement and is also used to make certain types of plaster.

Explanation:

Limestone heated

When limestone is heated strongly, the calcium carbonate it contains absorbs heat (endothermic ) and decomposes to form calcium oxide. ... Calcium oxide (also known as quicklime) is a key ingredient in the making of cement and is also used to make certain types of plaster.

Burning Limestone

Burning limestone, which is calcium carbonate, gives you quick lime, calcium oxide. Mixed with water this produces slaked lime, calcium hydroxide. ... This is soft when first mixed, but with time absorbs carbon dioxide from the atmosphere and hardens as it reverts back to calcium limestone.

Limestone exposed to heat and pressure.

Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. ... Under the conditions of metamorphism, the calcite in the limestone recrystallizes to form a rock that is a mass of interlocking calcite crystals.

Explanation:

code: 257 403 0731

Pass: HELLO

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Answer: A

Explanation:

Answer:

There is strong attraction or repulsion between the gas particles.In other words,they strongly interact with each other" is NOT an assumption made by kinetic molecular theory.

The theory that attempts to elucidate the behaviour of gases is known as kinetic molecular theory.

The postulates of kinetic molecular theory of gases are given below,

\bigstarGases consist of large number of identical particles(atoms or moleculesthat are so small and so far apart

\bigstar There is no force of attraction between the particles of a gas at ordinary temperature and pressure

\bigstarParticles of a gas are always in constant and random motion

\bigstarParticles of a gas move in all possible directions in straight lines. During their random motion, they       collide with each other and with the walls of the container

\bigstarCollisions of gas molecules are perfectly elastic. This means that total energy of molecules before and       after the collision remains same

\bigstarThe average kinetic energy (energy due to motion) of the gas particles is proportional to the temperature    measured in kelvin. As temperature increases, the particles move faster and have more energy

\bigstarAt any particular time, different particles in the gas have different speeds and hence different kinetic        energies.

\therefore From the above data it is clear that "There is strong attraction or repulsion between the gas particles.In other words,they strongly interact with each other" is NOT an assumption made by kinetic molecular theory.

Explanation:

According to Kinetic theory of gases, the kinetic energy of particles are derived from the temperature and not by their mass and velocity. Hence, option a is not an assumption of kinetic theory of gases.

According to kinetic theory of gases, gases substances are made of tiny particles. These particles when taken in a container have negligible volume compared to the volume of the container.

The collision between the gaseous particles and and between the particles and the wall make the pressure within the container. The kinetic energy of the particles is directly proportional to the temperature of the gas.

According to the theory, the kinetic energy is not determined from the mass and velocity of the particles, but by the temperature of the system. Hence, option a is not an assumption of kinetic molecular theory of gases.

Find more on kinetic theory:

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Answer:

106g/mol

Explanation:

Mass of Na=2×23=46

Mass of C=12

Mass of O=3×16=48

Total mass of Na2CO3=106g/mol

The molecules or coefficient of N2 would be 1, that of H2 would 3, and that of NH3 would be 2.

From the balanced equation of the reaction:

[tex]N_2 + 3H_2 ---> 2NH_3[/tex]

1 mole of N2 will react with 3 moles of H2 in order to produce 2 moles of NH3. In order words, the mole ratio of N2 to H2 to NH3 in the reaction will always be 1:3:2.

Thus, the coefficient of N2 in the equation will be 1, the coefficient of H2 will be 3, and the coefficient of NH3 will be 2.

More on balancing equations can be found here: https://brainly.com/question/7181548?referrer=searchResults

Answer: 3:2

this is the answer I came up with that was correct after I did the question in ck12

Answer:

Individual Characteristics are properties of physical evidence that can be attributed to a common source with a high degree of certainty. Examples of individual evidence include anything that contains nuclear DNA, toolmarks, and fingerprints.

Explanation:

Answer:

Physical

Explanation:

Hope this helps :)

Answer:

Molar mass of Al2O3 = 101.961276 g/mol

This compound is also known as Aluminium Oxide.

Convert grams Al2O3 to moles or moles Al2O3 to grams

Molecular weight calculation:

26.981538*2 + 15.9994*3

Percent composition by element

Element Symbol Atomic Mass # of Atoms Mass Percent

Aluminium Al 26.981538 2 52.925%

Oxygen O 15.9994 3 47.075%

Explanation:

Percent composition by element

Element Symbol Mass Percent

Aluminium Al 52.925%

Oxygen O 47.075%

Answer:

True

Explanation:

Answer:

62.00

Explanation:

H2 means that there are two moles of hydrogen so multiply the atomic mass by two (1.01 × 2 = 2.02)

C only has one mole sp leave 12.01 alone

And multiply oxygen by 3 because there are three moles of oxygen (15.99 × 3 = 47.97)

Add them all together!

2.02 + 12.01 + 47.97 = 62.00 for molar mass

Answer:

false

Explanation:

Answer:

True

Explanation:

they can get up to several hundreds of feet.

Answer:

D

Explanation:

The salamanders undergo se×ual reproduction.

This is defined as the production of new organisms by the combination of genetic information of two individuals of different genders.

Thus results in variations in the offsprings produced which us why the Salamanders had different color patches.

Read more about Se×ual reproduction here https://brainly.com/question/815744

Answer:

Salmonella

Poultry

Explanation:

I'm a cook. :D

Answer:

just put random words thats what i always do i never got a grade lower than c

Answer:

D

Explanation:

I learned this last year.

Answer:

See Explanations

Explanation:

The Empirical Gas Laws include ...

Boyles Law => P₁V₁ = P₂V₂

Charles Law => T₁/V₁ = T₂/V₂

Gay-Lussac's Law => P₁/T₁= P₂/T₂

Avogadro's Law => V₁/n₁ = V₂/n₂

Combined Gas Law => P₁V₁/T₁ = P₂V₂/T₂

Ideal Gas Law => PV = nRT; R = 0.08206 L·Atm/mol·K

One only needs to learn the 'Combined Gas Law' in that it embodies all of the gas law problems.

Start with a simple table for P, V & T and enter given data. If a variable is not given, assume it is constant. Set up P₁V₁/n₁T₁ = P₂V₂/n₂T₂ and substitute given data. Solve for unknown.

Your Problems:

1. P₁ = 1 Atm        P₂ = 3 Atm

  V₁ = 300ml      V₂ = ?

  T₁ = Constant  T₂ = T₁

   n₁ = Constant  n₂ = n₁

P₁V₁/n₁T₁ = P₂V₂/n₂T₂  

=> (1Atm)(300ml)/(Constant)(Constant) = (3Atm)(V₂)/(Constant)(Constant)

=> (1Atm)(300ml) = (3Atm)V₂

=> V₂ = (1Atm)(300ml)/(3Atm) = 100ml

2. P₁ = 1 Atm        P₂ = ?

   V₁ = Constant  V₂ = V₁

   T₁ = 273K         T₂ = 82K

   n₁ = Constant  n₂ = n₁

P₁V₁/n₁T₁ = P₂V₂/n₂T₂

=> (1Atm)(Constant)/(273K)(Constant) = (P₂)(Constant)/(82K)(Constant)

=> (1Atm)/(273K) = (P₂)/(82K)

=> P₂ = (1Atm)(82K)/(273K)

=> P₂ = 0.3 Atm (1 sig-fig)

3. P₁ = 101.25kPa     P₂ = 506kPa

   V₁ = 5 Liters         V₂ = ?

   T₁ = Constant       T₂ = T₁

   n₁ = Constant  n₂ = n₁

P₁V₁/n₁T₁ = P₂V₂/n₂T₂

=> (101.25kPa)(5L)/(Constant)(Constant) = (506kPa)(V₂)/(Constant)(Constant)

=> (101.25kPa)(5L) =  (506kPa)(V₂)

=> V₂ = (101.25kPa)(5L)/(506kPa)

=> V₂ = 1.00 Liter

4. P₁ = Constant       P₂ = P₁

   V₁ = 3.2 Liters      V₂ = ?

   T₁ = 273°C + 273 = 546K       T₂ = 400°C + 273 =673K*

   n₁ = Constant  n₂ = n₁

*Note => be sure to convert all temps to Kelvin when working empirical gas law problems. K = °C + 273

P₁V₁/n₁T₁ = P₂V₂/n₂T₂

=> (Constant)(3.2L)/(Constant)(546K) = (Constant)(V₂)/(Constant)(673K)

=> (3.2L)/(546K) = (V₂)/(673K)

=> V₂ = (3.2L)(673K)/(546K)

=> V₂ = 3.944 Liters ≅ 3.9 Liters (2 sig-figs)

The pH of the solution is 9.56.

Given:

Mol of NH₃ = 0.50

Mol of [tex]NH_4^+[/tex] = 0.20 to start (NH₄Cl dissolves completely)

Molarity = 1.0 M

30.0 mL of 1.0 M HCl is 0.0300 mol of HCl.

This will react with the NH₃ to produced 0.030 mol of [tex]NH_4^+[/tex] .

This equation is used to calculate pH. It is an approximate equation that shows the relationship between the pH or pOH of a solution and the pKa or pKb and the ratio of the concentrations of the dissociated chemical species

pH = pKa + log(base/acid)

pKa = 14 - pKb

pKa= 14 - 4.75

pKa= 9.25

pH = 9.25 + log(0.47/0.23)

pH = 9.56

Thus, the pH of the solution is 9.56.

Find more information about pH here:

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Answer:

Hi, valence electrons are the number of electrons present in the outermost shells of atoms of elements, they affect how sharing or transfer of electrons takes place when the atoms go into any reaction.

they also determine the oxidation state of the atom.

for example, hydrogen has one electron in its outermost shell. therefore in any reactions it tends to loose that electron or gain one more to become stable.

the reason why elements go into reactions is to become stable (to have a complete duplet or octet structure).

As you know, each shells aside from the first has maximum of 8 electrons. so for a element like chlorine which have 7 electrons in the valence shell will gain one electrons in reactions to become stable(have a complete octet structure)

valence electrons also classifies elements( metal or non-metal)

if an element have 1, 2 or 3 valence electron(s), it is likely to be a metal

if an element have 4 or 5, it can be a non-metal or a metalliod (semiconductor)

if an element have 6 or 7, it is likely to be a non-metal

if an element have 8, it is a noble/inert gas

this also explains why noble gases do not react since they already have a duplet structure, they do not need to go into reaction.

good lucks on your exams.

Answer:

The number of electrons in an atom's outermost valence shell governs its chemical properties. ... This tendency is called the octet rule, because the atoms have eight valence electrons. METALS. The most reactive metallic elements are metals from Group 1 (e.g., Na or K ) or Group 2 (e.g., Mg or Ca )

hope this helps.