10 POINTS PLS HELP
Combustion occurs when _____.

oxidation reactions are very slow
oxidation reactions are so fast the substance catches fire
oxygen is removed from another substance
machines use chemical energy to do work

Answer:

79.63

Explanation:

Answer:

The magnesium ion is much smaller than the magnesium atom because magnesium atom contains more electrons as compared to magnesium ion. Explanation: ... Whereas when an atom tends to lose an electron then it acquires a positive charge and size of the atom tends to increase.

Answer:

Because it looses it two electrons to form a stable octet Ionic form..........

Explanation:

I DONT UNDERSTAND WHAT U WANT TO SAY

Answer:

no one additions exceed the capacity of the buffer

Explanation:

given

Volume buffer = 500.0 mL = 0.5 L

mol HNO₂ = 0.5 L × 0.100 mol/L = 0.05 mol HNO₂

mol NO₂⁻ = 0.5 L × 0.150 mol/L = 0.075 mol NO₂⁻

solution

we know when any base more than 0.05 (HNO2) than exceed buffer capacity

and when any base more than 0.075 (KNO2) than exceed buffer capacity

when we add 250 mg NaOH (0.250 g)

than molar mass NaOH =40 g/mol

and mol NaOH = 0.250 g ÷ 40g/mol

mol NaOH  = 0.00625 mol

0.00625 mol NaOH will be neutralized by 0.00625 mol HNO₂

so it would not exceed the capacity of the buffer.

and

when we add 350 mg KOH (0.350 g)

than molar mass KOH =56.10 g

and mol KOH = 0.350 g ÷ 56.10 g/mol

mol KOH = 0.0062 mol

here also capacity of the buffer will not be exceeded

and

now we  add 1.25 g HBr

than molar mass HBr = 80.91 g/mol

and mol HBr = 1.25 g  ÷ 80.91 g/mol

mol HBr = 0.015 mol

0.015 mol Hbr will neutralize 0.015 mol NO₂⁻  

so the capacity will not be exceeded.

and

we add 1.35 g HI  

molar mass HI = 127.91 g/mol

so mol HI = 1.35 g ÷ 127.91 g/mol

mol HI = 0.011 mol

capacity of the buffer will not be exceed

Graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. Therefore, this happen because of weak covalent bond.

Graphite is among the most prevalent carbon allotropes. It is also the stable allotrope for carbon, and as such, it is employed in electrochemistry to define the heat of synthesis of carbon compounds. With a hardness of 2.09-2.23 g/cm3, graphite is an excellent conductor of electricity and heat.

Graphite is a large covalent structure in which each carbon atom is covalently linked to three other carbon atoms. Graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. This happen because of weak covalent bond.

Therefore, graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. This happen because of weak covalent bond.

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Answer:

HI(aq) + KOH(aq) --> KI(aq) + H2O(l)

Explanation:

HI is an acid and KOH is a base, this means that the reaction would be a neutralization reaction.

The equation is given as;

HI + KOH --> KI + H2O

Adding the physical states we have;

HI(aq) + KOH(aq) --> KI(aq) + H2O(l)

Taking into account the reaction stoichiometry and the definition of molarity, 175 mL of 2 M H₂SO₄ will react with 28.0 g of NaOH.

In first place, the balanced reaction is:

H₂SO₄ + 2 NaOH  → Na₂SO₄ + 2 H₂O

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

Molar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.

The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:

[tex]Molarity= \frac{number of moles}{volume}[/tex]

Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].

The following rule of three can be applied: If by reaction stoichiometry 80 grams of NaOH react with 1 mole of H₂SO₄, 28 grams of NaOH react with how many moles of H₂SO₄?

[tex]moles of H_{2}S O_{4} =\frac{28 grams of NaOHx1 mole ofH_{2}S O_{4} }{80 grams of NaOH}[/tex]

moles of H₂SO₄= 0.35 moles

In this case, you know:

Replacing in the definition of molarity:

[tex]2 \frac{moles}{liter}= \frac{0.35 moles}{volume}[/tex]

Solving:

2 [tex]\frac{moles}{liter}[/tex] × volume= 0.35 moles

volume= 0.35 moles ÷ 2 [tex]\frac{moles}{liter}[/tex]

volume= 0.175 liters= 175 mL (being 1 L= 1000 mL)

Finally, 175 mL of 2 M H₂SO₄ will react with 28.0 g of NaOH.

Learn more about

the reaction stoichiometry:

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molarity:

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Answer:

19.6 moles of aluminum sulfate

Explanation:

Given parameters:

Number of sulfur atoms  = 3.54 x 10²⁵  atoms

Unknown:

Number of moles of aluminum sulfate = ?

Solution:

Aluminum sulfate is expressed as;

        Al₂(SO₄)₃

  1 mole of Aluminum sulfate contains 3 moles of sulfur.

 6.02 x 10²³ atoms are found in 1 mole of any substance;

 3.54 x 10²⁵  sulfur atoms will be found in [tex]\frac{3.54 x 10^{25} }{6.02 x 10^{23} }[/tex]   =  58.8moles of sulfur

1 mole of Aluminum sulfate contains 3 moles of sulfur.

 or ;

      3 moles of sulfur is contained in 1 mole of aluminum sulfate

     58.8moles of sulfur will contain [tex]\frac{58.8}{3}[/tex] moles of aluminum sulfate

                                                       = 19.6 moles of aluminum sulfate

Answer:

Mass of CO₂ produced = 20.328 g

Oxygen is limiting reagent.

Explanation:

Given data:

Mass of C₂H₂ = 13.7 g

Mass of O₂ = 18.5 g

Mass of CO₂ produced = ?

What is limiting reagent = ?

Solution:

Chemical equation:

2C₂H₂ + 5O₂      →     4CO₂ + 2H₂O

Number of moles of C₂H₂:

Number of moles = mass /molar mass

Number of moles = 13.7 g/ 26.04 g/mol

Number of moles = 0.526 mol

Number of moles of O₂:

Number of moles = mass /molar mass

Number of moles = 18.5 g/ 32 g/mol

Number of moles = 0.578 mol

Now we will compare the moles of CO₂ with C₂H₂ and O₂

                      C₂H₂              :                CO₂

                           2                :                 4

                       0.526            :              4/2×0.526 = 1.052

                      O₂                  :                   CO₂

                        5                   :                     4

                      0.578             :                4/5×0.578 = 0.462

The number of moles of  CO₂ produced by O₂  are less thus oxygen will be limiting reactant.

Mass of CO₂ produced:

Mass = number of moles × molar mass

Mass = 0.462 mol × 44 g/mol

Mass = 20.328 g

Answer:

cheese and bread

Explanation:

2 bread 1 cheese = cheese sandwich

Answer:

Increases

Explanation:

The gravitational potential energy of an object increases as you bring it higher with respect to the ground.

Gravitational potential energy depends on the mass, height and gravity between two bodies;

   Gravitational potential energy  = mgh

m is the mass

g is the height

h is the height

Answer:

B

Explanation:

a mole is "a chemist's dozen" lol

Answer:

Ionic

Explanation:

Because sulphur is a non-metal and cesium is part of the group 1 Alkali Metals, this creates an ionic bond

Ionic bonds are created from one metal and one non-metal element.

This still is declared as Ionic despite the balance of this is Cs2S

Answer:

It’s b;)

Explanation:

Answer:

B is correct

Explanation:

Answer:

0.44L

Explanation:

Given parameters:

  Initial volume  = 0.75L

  Initial temperature  = 25°C  = 273 + 25 = 298K

  Final temperature  = -100°C  = 273 + (-100) = 173K

Unknown:

New volume of the balloon = ?

Solution:

According to Charles's law;

   "the volume of a fixed mass of a gas varies directly as its absolute temperature if the pressure is constant".

Mathematically;

    [tex]\frac{V_{1} }{T_{1} }[/tex]   =  [tex]\frac{V_{2} }{T_{2} }[/tex]  

  V and T are temperature values

  1 and 2 are the initial and final states

Insert the parameters and solve;

   [tex]\frac{0.75}{298}[/tex]   = [tex]\frac{V_{2} }{173}[/tex]  

    298V₂   = 129.75

           V₂  = 0.44L

Answer:

here are what i have so far, im doing this right now

Explanation:

Plate Tectonics Lab Report

Instructions: In the Plate Tectonic lab you will investigate the interactions between continental and oceanic plates at convergent, divergent, and transform boundaries around the globe. Record your observations in the lab report below. Y

Objective(s):  

To look at interactions between continental and oceanic plates, etc.  

Hypothesis:

In this section, please include the if/then statements you developed during your lab activity for each location on the map. These statements reflect your predicted outcomes for the experiment.

Location One: Select three events that you predict will be observed. If I explore two continental plates at a convergent boundary, then I will observe:

• earthquakes  

• mountains

• volcanoes

Location Two: Select three events that you predict will be observed. If explore two continental plates at a divergent boundary, then I will observe:  

• ocean formation  

• volcanoes

• seafloor spreading

you will submit your completed report

ps; you might want to change up the objective.

A geological event is a brief, spatially diverse, dynamic and ongoing occurrence in the history of the Earth.

A geological event is a brief, spatially diverse, dynamic (diachronous), and ongoing occurrence in the history of the Earth that aids in the modification of the Earth system and the production of geological strata. The concept of event stratigraphy initially came up as a way to identify, analyse, and correlate how significant physical and biological events have affected the overall stratigraphical record.

Israel's Dead Sea basin Holocene sediments contain seismic activity. This can be considered a record of a geological event, an earthquake, that altered the strata. Geological events can occur over timescales of order of magnitude, from just a few seconds through millions of years, as well as on a variety of spatial scales, from the local to the globe.

1. Volcanoes and minor earthquakes

2. Volcanoes, earthquakes and fold mountains.

3. Earthquakes and fold mountains.

4. Magma from volcanoes is filled with nutrients that makes land fertile.

Therefore, a geological event is a brief, spatially diverse, dynamic and ongoing occurrence in the history of the Earth.

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Answer:

The advantages of using an indicator to inform pH measurements:

It gives a mathematically result of the pH, in addition, it gives the precise pH of solvent, and it also gives an idea of the straight of the solution also.

Now, the advantage of using a pH meter:

It is a rapid method to characterize between acids, bases. However, this method does not show how strong acid or base actually are, plus it tends to gives a range of acidity or basicity not quite accurate as a result.

The work energy of this process : 2337.298 J

The laws of thermodynamics 1 state that: energy can be changed but cannot be destroyed or created  

ΔU=Q-W

Q=m.c.Δt

[tex]\tt Q=8.85\times 2.650\times 63.2=1482.198~J[/tex]

the work (W) :

[tex]\tt W=Q-\Delta U\\\\W=1482.198-(-855.1)=2337.298~J[/tex]

Answer:

Graham's law states that the rate of diffusion or of effusion of a gas is inversely proportional to the square root of its molecular weight

Explanation:

Answer:

Adenine pairs with thymine and guanine pairs with cytosine

Answer:

The answer is B

Explanation:

I had the same question and I chose B and it was correct.

Answer:

B. Carbon needs more than just three bonds to reach a noble gas

Explanation:

PLATO ANSWER

PLATO EXPLANATION-

Each hydrogen atom can make only one bond, but a carbon atom needs four bonds to be stable. Therefore, three hydrogen atoms are not enough for the carbon atom to make four bonds.

Answer:

d. It's ability to lose electrons

Answer:

Mantle convection

Explanation:

The source of the force that moves tectonic plates along plate boundaries is as a result of the mantle convection.

Answer:

Explanation:

no of molecules=5.65*10^21

NA=6.23*10^23

no of moles=no of molecules/avogadro number

no of moles=5.65*10^21/6.23*10^23

no of moles=9.07*10^-3

now we know that

no of moles=mass/molar mass

mass=no of moles*molar mass

mass=9.07*10^-3*89.06

mass=0.808 g

Answer:

Fair test.

PLS GIVE BRAINLIEST

Answer:

Explanation:

no of moles of C2H6=10/30=0.33

complete combustion of 2 moles of ethane produce 4 moles of CO2 therefore 0.33 moles of C2H6 produced 0.66 moles of CO2

now moles =given mass/molar mass

mass= moles*molar mass

mass of CO2=0.67*44=29.48 g

Answer:

The answer is 95 degree celcius

The concentrations : 0.15 M

pH=11.21

The ionization of ammonia in water :

NH₃+H₂O⇒NH₄OH

NH₃+H₂O⇒NH₄⁺ + OH⁻

The concentrations of all species present in the solution = 0.15 M

Kb=1.8 x 10⁻⁵

M=0.15

[tex]\tt [OH^-]=\sqrt{Kb.M}\\\\(OH^-]=\sqrt{1.8\times 10^{-5}\times 0.15}\\\\(OH^-]=\sqrt{2.7\times 10^{-6}}=1.64\times 10^{-3}[/tex]

[tex]\tt pOH=-log[OH^-]\\\\pOH=3-log~1.64=2.79\\\\pH=14-2.79=11.21[/tex]