How can flame color identify an unknown metal?
How can a spectrum positively identify an element?
How can astronomers tell which elements a star contains without a sample of it?

Answer:

1.7 mol

Explanation:

This is an ideal gas problem. So many units! That's the tip-off usually.

PV=nRT

First convert kPA to atm 1 atm=101.3 kPA so 9.86/101.3 = .097311 atm

(.097311 atm x 500L) = n · 0821 L·atm/mol·K · 348K

Do your multiplication then divide to get n alone and you should get 1.7 mol

Answer:

K, or Potassium

Explanation:

Answer:

Copper is typically a solid and has a coppery, bronzy color. It is a metal and has a relatively high melting point. It has a strong luster and can conduct electricity.

Answer:

RESHAPE BY A FORCE.

Explanation:

1. It can be reshaped by a force. Physical property can be observed and measured without any changes in molecular composition.

2. A physical property is one that can be change without altering the identity of the substance. These set of properties is not concentration dependent they are use to describe matter. Example are: density, solubility, melting point and color and odor. For this case the second option seems to fit the description it can be reshape by force.

Answer:

I hope it's helpful for you....

Explanation:

Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, a hydrogen atom.

Answer:

they are molecules with normal bonds rather than partial bonds and can occasionally be isolated.

Explanation:

In chemistry, reaction intermediates are species that are formed from reactants and are subsequently being transformed into products as the reaction progresses. In other words,  reaction intermediates are species that do not appear in a balanced reaction equation but occur somewhere along the reaction mechanism of a non-elementary reaction. They are usually short lived species that possess a high amount of energy. They may or may not be isolated.

They are often molecular species with normal bonds unlike activated complexes that are sometimes hypervalent species.

Answer:

a. Aqueous

Explanation:

Took the test

Answer:

So, weight per litre (1.25g/l) times 22.4 l/mole equals the mole weight (28 g/mole).

A condition in which bones become weak and brittle.

The body constantly absorbs and replaces bone tissue. With osteoporosis, new bone creation doesn't keep up with old bone removal.

thus 2) is correct.

a disease in which bone tissue becomes breakable and thin.

if it helps don't forget to like and Mark me

Answer:

see explanations

Explanation:

The graphic is the heating curve for water. Note that it is divided into 5 distinct heat flow segments. The segments with changing slopes are single phase segments with changes in temperature values. From left to right segment A is solid ice being warmed to it's melting point. Segment B is the melting segment in which 2 phases are in contact (solid + liquid). Note that addition of heat does not change the temperature. Segment C is warming of the liquid (single phase) up to its boiling point. At the boiling point the liquid begins to pass into the gas phase and again 2 phases are in contact; i.e., liquid & gas. Note again when two phases are in contact no temperature change occurs. Finally, segment E is the heating of the pure, single phase gas.

In summary ...

Segment A => heating single phase (solid) ice up to melting pt.

Segment B => melting of ice => 2 phases in contact (s & l) ΔT = ∅.

Segment C => heating single phase (liquid) water up to boiling pt.

Segment D => boiling of liquid => 2 phases in contact (l & g). ΔT = ∅.

Segment E => heating single phase (steam) up to desired temperature.

For what it's worth, the equation for the segments that show increasing temperature values is q = mcΔT (m= mass, c = specific heat & ΔT temp change.

The segments with zero slopes (horizontal lines) are defined by equations  q = m·ΔHₓ where m = mass & ΔHₓ = heat of fusion (a constant = 335 j/g). The same is true for the line at 100°C where q = m·ΔH(v) where m = mass & ΔH(v) is the heat of vaporization (a constant = 2259 j/g.

Calculations involve calculating the amount heat transfer for each segment individually and then adding the heat values to obtain the total heat transfer.

If you need more instruction on this topic, kick back a note and I'll try to help clarify. Good Luck, Doc :-)

Answer:

Picture attached has answers

Explanation:

Answer:

F = ma, or force is equal to mass times acceleration.

This requires familiarity with the different theories (or concepts) of acids and bases.

On the Arrhenius concept, an acid is a substance that produces an H⁺ ion in water such that the H⁺ concentration increases, and a base is a substance that produces an OH⁻ ion in water such that the OH⁻ concentration increases.

On the Brønsted–Lowry concept, an acid is a substance that donates a proton (which is basically an H⁺ ion) in a solvent, and a base is a substance that accepts a proton in a solvent.

On the Lewis concept, an acid is a substance that accepts an electron pair in a solvent, and a base is a substance that donates an electron pair in a solvent.

The concepts become progressively broader, i.e., the Arrhenius concept is the most restrictive and the Lewis concept is the least restrictive. As a corollary, an Arrhenius acid or base is also both a Brønsted–Lowry acid or base and a Lewis acid or base, respectively; a Brønsted–Lowry acid or base is not necessarily an Arrhenius acid or base, but an Arrhenius acid or base is also a Lewis acid or base, respectively. And finally, a Lewis acid or base may not necessarily be either an Arrhenius or a Brønsted–Lowry acid or base.

So, with the above concepts in mind, we can match the statements in column A with the type of acid or base in column B:

[tex]\begin{center}\begin{tabular}{ c c } 1 & Bronsted Lowry acid \\ 2 & Bronsted Lowry base \\ 3 & Arrhenius acid \\ 4 & Arrhenius base \\ 5 & Lewis base \\ 6 & Lewis acid\end{tabular}\end{center}[/tex]

Answer:

Explanation: It is already known that 1 mole of the gas( or 32g of O2) is equivalent to 22.4 Litres of the oxygen gas. So, 8g is equivalent to = (22.4/32) × 8 = 5.6 L of the gas.

Answer:

15.4%

Explanation:

If Ka = 0.54 mM = 1.51x10⁻⁵

Then;

C₄H₈O₂               -------->            C₄H₇O₂⁻          +           H⁺

I                    0.54x10⁻³                             0                                0

E                   0.54x10⁻³(1-x)                      0.54x10⁻³x                0.54x10⁻³x

Recall that x is the percentage degree of dissociation

From the ICE table;

Ka = [C₄H₇O₂⁻] [ H⁺]/[C₄H₈O₂]

1.51x10⁻⁵=(0.54x10⁻³x) (0.54x10⁻³x)/ 0.54x10⁻³(1-x)  

1.51x10⁻⁵ = 0.54x10⁻³x^2/1-x

1.51x10⁻⁵(1-x) = 0.54x10⁻³x^2

1.51x10⁻⁵ - 1.51x10⁻⁵x = 0.54x10⁻³x^2

Hence;

0.54x10⁻³x^2 + 1.51x10⁻⁵x - 1.51x10⁻⁵=0

x^2 + 0.028x - 0.028 = 0

Solving the quadratic equation here;

x = 0.154 or −0.182

Ignoring the negative result, x = 0.154

Hence, fraction of butanoic acid that is in the dissociated form in this solution = 15.4%

Answer:

The periodic table has been there for such a long time and how it is helpful in all science it is the element itself. How the element is used in real life. For example, oxygen is used in the atmosphere. Plants use carbon in order to covert it into oxygen more like that

Answer:

Why does internet cost so much? Equipment and installation: One of the main reasons for internet prices to run high is the cost of equipment and installation in new service areas. Fiber optic cables are expensive, so fiber optic internet providers may have higher prices to recoup the costs of installing new lines.Apr 21, 2021Explanation:

Answer:

2.34

Explanation:

Answer:

Density is a physical property that is determined by dividing the mass of a given amount of a substance by its volume.

Explanation:

Answer:

Wind

Explanation:

Wind turbines make energy by the movement of the natural force on earth called 'wind' and renewable resources are resources that can be made from natural and environment-safe objects or things (e.g. Water, Geothermal Heat, The Sun, and Wind)

Answer:

The food chain begins with the sun: plants get their energy by photosynthesizing sunlight into energy, and then herbivores eat those plants to get their energy. Carnivores who then eat the herbivores are getting that sunlight passed along from sun to plant to herbivore to carnivore.

Answer: a. A solid melts: [tex]\Delta S=+ve[/tex]

b. a vapor is converted to solid: [tex]\Delta S=-ve[/tex]

c. a liquid freezes:  [tex]\Delta S=-ve[/tex]

d. A solid sublimes:  [tex]\Delta S=+ve[/tex]

e.  a vapor condenses to liquid :  [tex]\Delta S=-ve[/tex]

f. a liquid boils:   [tex]\Delta S=+ve[/tex]

g. dissolving a tablespoon of salt in water:  [tex]\Delta S=+ve[/tex]

h. combustion of gasoline:  [tex]\Delta S=+ve[/tex]

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from  an ordered arrangement to a disordered arrangement, the entropy change is negative and vice versa.

a. A solid melts: The solid is converting to liquid, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

b. a vapor is converted to solid: The gas  is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger Thus the entropy change [tex](\Delta S)[/tex] is negative.

c. a liquid freezes: The liquid is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change [tex](\Delta S)[/tex] is negative.

d. A solid sublimes: The solid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

e.  a vapor condenses to liquid : The gas  is converting to liquid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change [tex](\Delta S)[/tex] is negative.

f. a liquid boils: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

g. dissolving a tablespoon of salt in water: The solid is converting to ions , thus the randomness is increasing as the ions can move freely. Thus the entropy change [tex](\Delta S)[/tex] is positive.

h. combustion of gasoline: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

Answer:

56.8 g

Explanation:

Your first conversion factor is the molar mass of H2O to convert from grams of water to moles. Your second conversion factor is the mole ratio of 2 mol C2H10 for every 10 mol H2O. Your last conversion factor is the molar mass of C2H10 to convert from moles back to grams.

150. g H2O • (1 mol H2O / 18.02 g H2O) • (2 mol C2H10 / 10 mol H2O) • (34.1 g C2H10 / 1 mol C2H10) = 56.8 g C2H10

Answer:

a

Explanation:

Answer:

A decrease in temperature decreases the number of collisions between molecules . The reaction rate will  decrease

Explanation:

Answer:

The correct answer is -

if the potential energy of reactants is less than the potential energy then it is an endothermic reaction and if the potential energy of reactants is more than the products it is an exothermic reaction.

Explanation:

The potential energy graph represents the energy change in a reaction as it progresses. In the initial part of the reaction, the energy shows are the energy of reactants that takes part in the reaction, and in the later phase, the energy has represented the energy of products of the reaction.

To find the reaction if it is endothermic or exothermic one can see if the potential energy is increased or decrease with the progress of the reaction. if the reaction is increasing in energy with the progress then it is endothermic and exothermic in less energy.

Answer:

4.90

Explanation:

10- 5.0