Temperature (°C) 5
Heating Curve for Water
160
140
2 120
100
80
60
40
20
0
-20
1 2 3 4 5 6 7
Time (min)
8
9
10
At what temperature does the solid start melting?
0 -20°C
0°C
20°C
80°C

Answer: In ionic bonding (a noble gas configuration is formed for each element or ion).

Explanation:

IONIC bonding, which is also called electrovalent bonding involves the complete transfer of electrons from one atom to another in order to attain a noble gas electron configuration.

The noble gases or group 0 elements have a completely filled outermost shell of eight electrons. This makes them generally very stable, that is, unreactive. There is a natural drive for other atoms to attain the electron configuration of group 0 (inert gases) elements. This usually results in atoms entering into chemical combinations by losing, gaining or sharing electrons.

Ionia compound such as sodium chloride

--> have high melting points because alot of heat energy is required to break the attractive forces between the ions;

--> are hard and brittle;

--> are soluble in water;

--> conduct electricity when in solution or molten form because the ions are able to move about, that is, they are electrolytes

Answer:

soluble because all compounds containing K are soluble

Explanation:

Most metal hydroxides are insoluble. However, alkali metal hydroxides (such as KOH and NaOH) are very soluble.

In the case of KOH, the K cation is attracted to the electronegative oxygen on water. The OH anion is capable of hydrogen bonding to the water. (Notice how OH⁻ is simply the deprotonated form of water.)

The compound KOH is soluble insoluble, because all compounds containing K are insoluble insoluble, because all compounds containing OH- are in soluble soluble, because all compounds containing K are soluble soluble, because all compounds containing OH- are soluble insoluble, because KOH is insoluble

Alkalis are bases which are soluble in water. The basic alkalis are as follows:

Mg(OH)2 is insoluble in water.

In conclusion, KOH is a soluble base

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Answer:

Cl

Explanation:

n for Mg=m:Mm

=65.8:24

=2.74mol

n for Cl=m:Mm

=45.7:70

=0.65mol

According to the number of moles we can say that the limiting reagent is Cl as it has few moles.

Limiting agents are the reactant that determines the amount of the product in a reaction. In the reaction between magnesium and hydrochloric acid, the limiting reagent is HCl.

A limiting reagent is a substance that restricts or determines the amount of product formation in a reaction. They are the reactants with less number of moles and get consumed in the reaction before the other reactant.

The reaction between magnesium and hydrochloric acid is given by,

Mg(s) + 2HCl(aq)  → MgCl₂(aq) + H2(g)

Here, 1 mole of Mg and 2 moles of HCl are required to produce 1 mole of magnesium chloride.

The moles of Mg,

= 65.8 g ÷ 24.305

= 2.707 mol

And, moles of HCl

= 45.7 g ÷ 36.458

= 1.253 mol

The stoichiometric ratio Mg : HCl = 1:2

Hence, Mg = 2.707 ÷ 1 = 2.707  and HCl = 1.253 ÷ 2 = 0.6265

Therefore, HCl is the limiting reagent.

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Answer:

See explanation

Explanation:

The addition of an impurity lowers the melting point of a solid. If we add salt to ice, the melting point of the ice is lowered.

As this salty water is in contact with the ice, more of the salt dissolves to yield Na^+ and Cl^- and leads to the melting of more ice.

Freezing point is a colligative property hence it is affected by the presence of impurities. Hence, the addition of NaCl causes ice to melt faster.

Answer:

speed

Explanation:

hope it helps

keep smiling

Answer:

I could be wrong letter c

Answer:  1)  temperature, 2) add a catalyst, and 3) concentrations

Explanation:  A rise in temperature adds kinetic energy to the reactants, leading to more frequent, and energetic collisions, which will often accelerate the reaqction.  A catalyst is an agent that helps the reaction move forward more quickly by offering a substrate that aids in orienting the reactants for more efficient reaction.  A higher concentration increases the chances of collisons that result in products.

which experiment please involve a clip

Explanation:

here's the answer to your question

Explanation:

a chemical reaction in which the rate of reaction is proportional to the concentration of each of three reacting molecules

Answer:

C. 0.5 cal/g°C

Explanation:

Using the following equation:

Q = m × c × ∆T

Where;

Q = amount of heat absorbed/released (calories)

m = mass of substance (g)

c = specific heat capacity (calg/°C)

∆T = change of temperature (°C)

According to the information provided in this question;

m = 10g

c = ?

∆T = 20°C

Q = 100cal

Using Q = m × c × ∆T

c = Q ÷ (m × ∆T)

c = 100 ÷ (10 × 20)

c = 100 ÷ 200

c = 0.5 cal/g°C

Answer:

It's nitrogen

Explanation:

cuz it has valence 3 and  a diatomic gas at room temperature

Element X must be nitrogen.

The general formula AlX indicates that aluminum (Al) is reacting with a nonmetallic element represented by X to form a compound.

Since the compound AlX is said to be a diatomic gas at room temperature, it aligns with nitrogen (N2), which is a diatomic gas and a nonmetal.

Among the given options, nitrogen is the diatomic gas that best fits this description.

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Answer:

The correct answer is - D.  the energy stored inside the center of an atom.

Explanation:

Each atom has a small center in it called the nucleus and the energy that holds the nucleus or center of the atom together in the atom is known as nuclear energy.

It is the energy that is stored in the center of the atom and normally does not come out, however, in some radioactive atoms the sends some part of the energy as radiation.

Thus, the correct answer is - D.  the energy stored inside the center of an atom.

Answer:

2.7

Explanation:

Density= mass/volume

= 1.35/0.500

= 2.7

Answer:

The amount of acid rain caused by the burning of fossil fuels can be reduced by creating nitrogen oxides in the process of burning coal and other fossil fuels, some power plants are changing the way they burn coal. A great way to reduce acid rain is to produce energy without using fossil fuels. Instead, people can use renewable energy sources, such as solar and wind power.

Answer:

There are 24*60 minutes in a day (ignoring the imperfections of the natural world, the Earth and Sun). So there are 24*60 valid 24 hour times (excluding seconds) on a digital clock.

A measure of time representing the interval between consecutive passages of the Sun across the meridian, averaged over one year. 1 day = 24 hr (86,400 sec) and 60 minutes.

hope it helps ya mate! :-P

Answer:

J

Explanation:

Heat is measured in Joules (J)

Answer:Calor y temperatura son dos conceptos diferentes pero estrechamente relacionados. Observa que tienen diferentes unidades: la temperatura típicamente tiene unidades de grados Celsius (^\circ\text C  

∘

Cdegrees, start text, C, end text) o Kelvin (\text KKstart text, K, end text), y el calor tiene unidades de energía, joules (\text JJstart text, J, end text). La temperatura es una medida de la energía cinética promedio de los átomos o moléculas en el sistema. Las moléculas de agua en una taza de café caliente tienen una mayor energía cinética promedio que las moléculas de agua en una taza de té helado, lo que también significa que están moviéndose a una velocidad más alta. La temperatura también es una propiedad intensiva. Esto significa que no depende de qué tanta cantidad tengas de una sustancia (¡siempre y cuando esté toda a la misma temperatura!). Por esta razón, los químicos pueden utilizar el punto de fusión para poder identificar una sustancia pura: la temperatura a la cual se derrite es una propiedad de la sustancia que no depende de la masa de una muestra.

A nivel atómico, las moléculas en cada objeto están constantemente en movimiento y chocando entre sí. Cada vez que chocan, pueden transferir energía cinética. Cuando dos sistemas están en contacto, se va a transferir calor del sistema más caliente al más frío por medio de choques moleculares. La energía térmica va a fluir en esa dirección hasta que los dos objetos están a la misma temperatura. Cuando esto ocurre, decimos que están en equilibrio térmico.

Explanation:

Al calor a veces se le llama una magnitud de proceso, porque está definido en el contexto de un proceso por el cual se puede transferir energía. No decimos que una taza de café contiene calor, pero podemos hablar del calor transferido de la taza de café caliente a tu mano. El calor también es una propiedad extensiva, así que el cambio de temperatura que resulta al transferir calor a un sistema depende de cuántas moléculas hay en el sistema.

Answer:

if you have options please include them, but I'll give you an idea.

Explanation:

The existence of ions happens when atoms lose or gain electrons.

if an atom gains an electron it will become a negative ion (because electrons are negative, and you gained more negativity.)

if an atom loses an electron it will become a positive ion (because it has lost negativity, which is the electron that we've lost).

I hope it helps, if it does please mark me brainliest!

Answer:

The reactions of the cycloalkanes are generally just the same as the alkanes, with the exception of the very small ones - particularly cyclopropane. ... In the absence of UV light, cyclopropane can undergo addition reactions in which the ring is broken

Answer:

tác dụng với acid,

Explanation:

Answer:

C - 1.58 × 10^−7 M

Explanation:

The hydroxide ion concentration can be found from the pOH by the reverse mathematical operation employed to find the pOH. [OH-] = 10-pOH or [OH-] = antilog ( - pOH) Page 2 Example: What is the hydroxide ion concentration in a solution that has a pOH of 5.70? On a calculator calculate 10-5.70, or "inverse" log (- 5.70).

The concentration of hydronium ion C) - 1.58 × 10^−7 M

                                     ∴pH=6.80

The hydroxide ion concentration can be found from the pOH by the reverse

To calculate the pH of an aqueous solution we need to know the concentration of the hydronium ion in moles per liter (molarity).

The pH is then calculated using the expression:

pH = - log [H3O+]

       -log[6.80]

       - 1.58 × 10^−7 M

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Explanation:

here's the answer to your question

Answer:

None

Explanation:

Methylene is an organic compound and organic compounds consist of hydrogen atoms and Carbon atoms in n this case Methylene(CH2) has one carbon and two hydrogens .

Answer: methylene doesn't contain CL(chlorine) atoms

Explanation: the chemical formulae for Methylene is CH2

which means it contains only carbon and hydrogen atoms which is 1(one) carbon 2(two)hydrogen atoms

HOPE THIS HELPS!!

Answer:

volume gives a larger source of error in determination of density

Answer:

Density and volume are inversely proportional. The greater the volume, the lower the density.

Density= Mass/ Volume

Explanation:

Density= Mass/ Volume

A volume error may be due to the measuring instrument used. Different instruments have different resolutions, and therefore varying percentage uncertainties. An instrument with a higher resolution has a lower percentage error. A pipette will give a more accurate reading compared to a beaker. Density and volume are inversely proportional. The greater the volume, the lower the density.

Parallax error could also lead to inaccurate volume readings. The volume reading must be taken below the meniscus for a liquid such as water and above the meniscus for a liquid such as mercury.

Another source of error is the measurement of mass. Instruments that are used to determine mass have different percentage uncertainties. An electronic weighing scale is most likely to give an accurate reading. Density is directly proportional to mass. The greater the volume of the liquid, the greater its density.

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Answer:

sublimation

Explanation:

Answer:

1 Ca(NO3)2

Calcium- Ca, Valency 2

Nitrate- NO3, Valency 1

AFTER CRISS CROSS:

Ca1(NO3)2

Ca(NO3)2

2 sodium bicarbonate = NaHCO3

Na = Sodium = (Na)+

HCO3 = bicarbonate = (HCO3) -

Na HCO3

3 magnesium   nitrite

   +2                 _ 1

Mg2(NO3)2

4 Na    Cl

    +1    _1

formula NaCl

5 hydrogen         sulphide  

H                       SO4

+1                       _2

formula H2SO4

6  H    Cl

  +1     _1

HCl

7 AL2     HSO4

  +2        -2

AL2(HSO4)3

8  NH4   Cl

   +1      _1

NH4Cl

9 NH4     SO4

  +1           _2

(NH3)2SO4

10  H   NO3

    +1    _1

HNO3

Answer:

I hope that the link above will be helpful

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[tex]\boxed{\pmb{\green{\sf{2Mg +H_{2}SO_{4}\dashrightarrow H _{2}+Mg_{2}SO_{4}}}}}[/tex]

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