What does Hess's law state can be done in order to be able to react solid magnesium with oxygen gas safely (that is, without exposing the magnesium to flames)?A. More moles of solid magnesium can be added until the reaction is safe.B. More moles of oxygen gas can be added until the reaction is safe.C. The reaction can be broken down and performed in steps. D. The phase state of the reactants can be changed to match each other.E. The phase state of the products can be changed to match each other.

Answer:  Btu, British Thermal Unit is used to express thermal energy when working in pounds and degrees Farenheit.

Calories are used when working in grams and degrees Centigrade or Kelvin (SI units)

A Joule is the British system unit used to measure heat transfer.

Explanation:

Answer:

-3

Explanation:

Phosphorus becomes phosphide with a -3 charge

Answer:

The correct answer is 4.84

Explanation:

We use the Henderson Hasselbach's equation to calculate the pH of a buffer solution:

pH = pKa = log ( [conjugate base]/[weak acid])

In this case:

conjugate base: acetate ⇒ [conjugate base] =  [acetate] = 0.0200 M

weak acid: acetic acid ⇒ [weak acid] =  [acetic acid] = 0,0200 M

pH = pKa + log ([acetate]/[acetic acid])= pKa + log (0.0200 M/0.0200 M)

When a strong base- such as NaOH- is added, the acid reacts with OH⁻ to form the conjugate base. So, the conjugate base is increased while the acid is decreased. Thus, in 1 liter of solution we have:

acetate = (0,0200 mol/L x 1 L) + (2.0 mmol x 1 mol/1000 mmol) = 0.022 mol

acetic acid= (0,0200 mol/L x 1 L) - (2.0 mmol x 1 mol/1000 mmol) = 0.018 mol

Finally, we calculate the pH:

pH = 4.75 + log (0.022 mol /0.018 mol )= 4.84

Buffer has been the solution that resists the change in the pH of the solution with the addition of acid or base. The pH of buffer with NaOH has been 4.84.

The pH has been the hydrogen ion concentration in the solution. The pH has been equivalent to pKa and can be given as:

[tex]\rm pka=log\dfrac{[base]}{[acid]}[/tex]

The base in the buffer has been the acetate, while acetic acid act as the acid.

The concentration of NaOH added to the solution has been given as:

[tex]\rm Molarity=\dfrac{moles}{volume}\\\\ NaOH=\dfrac{0.002\;mol}{1\;L}\\\\ NaOH=0.002\;M[/tex]

The addition of NaOH adds the concentration of base, and neutralization reduces the concentration of acid. Thus, the new pKa can be given as:

[tex]\rm pKa=log\dfrac{0.2+0.002}{0.2-0.002} \\pKa=log\dfrac{0.022}{0.018}[/tex]

The new pH of the solution has been the sum of the old and the new pKa value.

Thus, the pH of the new buffer has been given as:

[tex]\rm pH=4.75+log\dfrac{0.022}{0.018}\\ pH=4.84[/tex]

The pH of buffer with NaOH has been 4.84.

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Answer:

167in

Explanation:

Given arithmetic;

        56.5in + 95.3in + 15in

To determine the correct significant digits, the sum cannot be more precise than the least precise value in the addition;

 The least precise is 15in and it is in 2significant places;

      56.5in

      95.3in

 +    15    in

......................

      166.8in

......................

The value is 167in

Answer:

Explanation:

he pH of the water will determine the toxic effects, if any, of these substances.

Pure water is neutral with the pH of 7. But when water combines with other substance the pH varies as per the acidity of the combining substance.

pH is the measure of acidity of a solution and mathematically it is the negative logarithm of hydrogen ion concentration. Acidic substance have a pH of less than 7 whereas, basic substance have higher pH value.

Water when combines with some acids, its acidity increases. For example acid rain resulting from the reaction of rain water with oxides of nitrogen and Sulphur forming nitric acid and sulphuric acid.

pH of water have a role in the toxic effects of components in water pH and alkalinity of water determines the coagulation of other substances in water.

Hence, the properties of other substance in water is pH dependent and might effect the alkalinity or acidity of water as well the properties of substances in water such as toxicity.

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Answer:D

Explanation:I did it on study island.

Radio waves are not used to generate medical images because as per the electromagnetic spectrum ,the radio waves  carry little energy that they pass through most atoms without interaction.

The electromagnetic spectrum consists of  radiation  which consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.

The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.

In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.

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Answer:

Manganese (Mn)

Explanation:

We know it's manganese because we are told it is an electrically neutral atom. This means it has the same number of protons and electrons. If it has 25 electrons, it has 25 protons. Protons tell us the atomic number of the atom, which also tells us the name of the element. Manganese is element 25 on the periodic table.

Answer:

I think it is A. the two forces are equal, or balanced, neither the table nor the book moves up or down.

Explanation:

Tome, the other options don’t make no sense

Answer:

[tex]M_{acid}=0.08892M[/tex]

Explanation:

Hello!

In this case, since the reaction between arsenic acid and potassium hydroxide is:

[tex]H_3AsO_4+3KOH\rightarrow K_3AsO_4+3H_2O[/tex]

Thus, since the mole ratio between the acid and the base is 1:3, at the equivalence point we can write:

[tex]3n_{acid}=n_{base}[/tex]

That in terms of molarities and volumes is:

[tex]3M_{acid}V_{acid}=M_{base}V_{base}[/tex]

Thus, the concentration of the arsenic acid is:

[tex]M_{acid}=\frac{M_{base}V_{base}}{3V_{acid}}=\frac{0.1894M*35.21mL}{3*25.00mL} \\\\M_{acid}=0.08892M[/tex]

Best regards!

The concentration (M) of arsenic acid in a solution of 25.00 mL is 0.088M.

Molarity of any solution will be calculated as:

M = n/V, where

V = volume

n is the moles and it will be calculated as:
n = W/M, where

W = given mass

M = molar mass

Given chemical reaction is:

H₃AsO₄ + 3KOH → K₃AsO₄ + 3H₂O

Moles of 35.21 mL of 0.1894 M KOH will be calculated as:

n = (0.1894)(0.035) = 0.0066 moles

From the stoichiometry of the reaction it is clear that:

1 mole of H₃AsO₄ = react with 3 moles of KOH

0.0066 moles of KOH = react with 1/3×0.0066= 0.0022 moles of H₃AsO₄

Now we calculate the molarity of H₃AsO₄ in 25mL of solution as:

M = 0.0022/0.025 = 0.088 M

Hence, required molarity is 0.088 M.

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Answer:

The temperature of the water decreases and so the reaction is endothermic

Explanation:

This option is correct because when the 5.0g potassium chloride (KCl) was added to the 100.0ml distilled water, the KCl made the water absorb heat coming from it which made the water decrease in temperature thereby causing an endothermic reaction.

An endothermic reaction actually takes place when the temperature of a system which is isolated decreases. The surroundings of a non-isolated system actually gains heat. While in an exothermic reaction, the temperature of a system increases due to the release or evolution of heat. This heat is released into the surroundings.

Answer:

okay I will help you just message me johnpatrick on messenger

Answer:

my gues is red not a 100% but its in the 700s

Explanation:

Answer:

1.5 moles H₂O

General Formulas and Concepts:

Chemistry - Stoichiometry

Explanation:

Step 1: Define

RxN:   2H₂ + O₂ → 2H₂O

Given:   0.750 moles O₂

Step 2: Stoich

[tex]0.750 \ mol \ O_2(\frac{2 \ mol \ H_2O}{1 \ mol \ O_2} )[/tex] = 1.5 moles H₂O

Step 3: Check

We are given 3 sig figs.

Since our answer is 2 sig figs, we don't need to round.

Answer:

The atmosphere

Explanation:

It reflects and traps the light outside of the Earth's Atmosphere?

I think, hope i helped.

Answer:

Because these ions contain more than one atom, they are called polyatomic ions. Polyatomic ions have characteristic formulas, names, and charges that should be memorized. For example, NO3− is the nitrate ion; it has one nitrogen atom and three oxygen atoms and an overall 1− charge.

Polyatomic Ions.

Name     Formula

sulfite ion SO32−

Explanation:

Answer:

A photon

Explanation:

When electrons pass close to the standing wave of light, they hit the particles that are called photons

Answer:

Kinetic energy

Explanation:

Fireworks convert chemical energy into kinetic energy to send them flying upward. Hope it is correct!

Answer:

Speeds up when temperature is increased and can travel through a solid

Explanation:

Answer:

Metalloids and ions

Explanation:

Mercury is not solid at room temperature. (Metals)

Many nonmetals aren't good at conducting electricity. Oxygen for example. (Nonmetals)

Metalloids are always solid at room temp and are fair conductors. (Metalloids)

Ions are same as metalloids. (Ions)

PLS GIVE BRAINLIEST

Answer:

1.44mole of CO

Explanation:

The reaction equation is given as:

         5C  + 2SO₂ →  CS₂ + 4CO

We check to see if the expression is balanced and it is so;

 Now;

 Given;

           1.8mole of C reacted; how many moles of CO are produced;

  From the balanced reaction equation:

             5 mole of C is expected to produce 4 mole of CO

             1.8 mole of C will then produce [tex]\frac{4 x 1.8}{5}[/tex] = 1.44mole of CO

Answer:

Deuterium and Lithium.

Explanation:

I searched it up on google.

Answer:

The classical cell theory was proposed by Theodor Schwann in 1839. There are three parts to this theory.

Explanation:

Answer:

Kb = 1.6 × 10⁻⁵

Explanation:

Step 1: Given data

Acid dissociation constant of hydrocyanic acid (Ka): 6.2 × 10⁻¹⁰

Concentration of cyanide ion (Cb): 0.1 M

Step 2: Calculate the basic dissociation constant (Kb) of cyanide ion

We have the Ka of HCN. We can calculate the Kb of its conjugate base using the following expression.

Ka × Kb = Kw = 1.0 × 10⁻¹⁴

Kb = 1.0 × 10⁻¹⁴/Ka

Kb = 1.0 × 10⁻¹⁴/6.2 × 10⁻¹⁰

Kb = 1.6 × 10⁻⁵

The  Kb for a 0.1 M solution of cyanide ion is :

- 1.6 × 10⁻⁵

Given:

Acid dissociation constant of hydrocyanic acid (Ka)= 6.2 × 10⁻¹⁰

Concentration of cyanide ion (Cb)= 0.1 M

Base dissociation constant (kb)=?

Ka × Kb = Kw = 1.0 × 10⁻¹⁴

Kb = 1.0 × 10⁻¹⁴/Ka

Kb = 1.0 × 10⁻¹⁴/6.2 × 10⁻¹⁰

Kb = 1.6 × 10⁻⁵

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Answer:

Butanoic acid.

Explanation:

Answer:

polar

Explanation:

because carbon and sulfur have different electronegativities, the S=C bond is polar.

The entire molecule is nonpolar however because the dipoles (polar bonds) cancel out due to the geometry of the molecule (linear)

K20

K = 1+

0 = 2-

K/0 = 1/2

the answer is K:O = 1:2

Answer:

0.0099M = [F⁻]

Explanation:

For BaF2, Ksp = 1.7x10⁻⁶

When BaF₂ is in solution, the equilibrium between the solid and the dissociated ions occurs as follows:

BaF₂(s) ⇄ Ba²⁺(aq) + 2F⁻(aq)

Where Ksp = 1.7x10⁻⁶ is defined as:

1.7x10⁻⁶ = [Ba²⁺] [F⁻]²

Where [] are equilibrium concentrations of each ion in solution.

That means you will add F⁻ until its concentration exceeds:

1.7x10⁻⁶ = [0.0173] [F⁻]²

9.827x10⁻⁵ = [F⁻]²

When more F⁻ is added, BaF₂ begins its precipitation.