A coffee cup calorimeter will not be used to
directly measure the enthalpy of magnesium
combustion because

✓ the coffee cups could melt.

The calorimeter is made of coffee cups instead of
a beaker because coffee cups are

✓ better insulators

than beakers.

You will not measure the enthalpy of the reaction
of

✓ H2 and 02

in the coffee cup calorimeter because this reaction involves gases
Instead, you will use a well-known published
value.

These are the correct answers on edge 2021

As provided in the question, the pH of a solution is equal to the negative logarithm of the H₃O⁺ concentration in the solution (the square brackets denote the molar concentration).

We are given a solution with an H₃O⁺ concentration of 5.6 × 10⁻⁹ M. So, the pH of this solution would be:

pH = -log[H₃O⁺] = -log(5.6 × 10⁻⁹ M) = 8.25.

A pH that is equal to 7 is neutral; less than 7, acidic; and greater than 7, basic. As 8.25 is greater than 7, this solution is basic.

Answer:(b) By referring to a periodic table or table of elements, we see that phosphorus (symbol P) has an atomic number of 15. Thus, each atom has 15 protons. The mass number of the ion is 15 + 16 = 31. Because the ion has 15 protons and 18 electrons (three more electrons than protons), its net charge is 3-

Answer:

Molarity=Moles of solute/volume of solution in Litres

Simply imputing your values

you have

0.75/65

0.0115M.

Answer:

sulfate

Explanation:

because it is anions

Answer:

Chemical energy

Explanation:

By the use of electrons and protons from water

Answer:

chemical energy

Explanation:

Photosynthesis is the process by which organisms that contain the pigment chlorophyll convert light energy into chemical energy which can be stored in the molecular bonds of organic molecules (e.g., sugars). Photosynthesis powers almost all trophic chains and food webs on the Earth.

Answer:

1665

Explanation:

In 1665, Robert Hooke was the first to observe cork cells and their characteristic hexagonal shape, using the first optical microscope, which was invented by him at that time.

Answer:

Calcium oxide: CaO

Copper (II) nitrate: Cu(NO₃)₂

Ammonium chloride: NH₄Cl

Magnesium sulfate: MgSO₄

Copper (I) oxide: Cu₂O

Calcium chloride: CaCl₂

Explanation:

Hello there!

In this case, according the IUPAC rules for naming this inorganic salts, whereas calcium, copper (II), ammonium, magnesium and copper (I) are the cations and oxide, nitrate, chloride and sulfate are the anions, we proceed as follows:

Calcium oxide: CaO

Copper (II) nitrate: Cu(NO₃)₂

Ammonium chloride: NH₄Cl

Magnesium sulfate: MgSO₄

Copper (I) oxide: Cu₂O

Calcium chloride: CaCl₂

Best regards!

Answer:

pH= 4; pOH= 10

Explanation:

HCl is a strong acid and therefore dissociates completely in a solution of water via HCl + H2O --> Cl- + H3O+.

Because it is a strong acid, [HCl] = [H3O+].

[HCl]= [H3O+]= (0.005 mol)/(50L)= 1.0 x 10^-4

pH= -log[H3O+]

pH= -log(1.0 x 10^-4)= 4

pH + pOH = 14

4 + pOH = 14

pOH= 10

Answer: chlorophyll

Explanation: Photosynthetic cells contain chlorophyll and other light-sensitive pigments that capture solar energy.

Answer: The correct option is option B (the concentrations of the reactants and products have reached constant values).

Explanation:

CHEMICAL EQUILIBRIUM is defined as a state which is attained in a chemical system where by forward reaction occurs at the same rate with the backward reaction leading to CONSTANT CONCENTRATIONS of the reactants and the products. Chemical equilibrium is achievable in a closed Chemical system so that none of the reactants or products would escape be they gaseous or otherwise.

Chemical equilibrium occurs in a type of reaction called reversible reactions. Reversible reactions is one that can go in either direction depending on the condition of the system. In other words, reactants form products and under favourable conditions products react together to reform the reactants. For example,

3Fe(s) + 4H2O(l) <-------> Fe3O4(s) + 4H2(g)

As the above reversible reaction proceeds, a time is reached when the rate of forward reaction { which is the formation of Fe3O4(s) + 4H2(g)} is equal to the rate of the backward reaction {which is the formation of 3Fe(s) + 4H2O(l)}. At this point, concentrations of the reactants and products have reached constant values.

When a chemical system is at equilibrium then the concentrations of the reactants and products have reached constant values.

Chemical equilibrium is a state occur in any reversible reaction, where the rate of forward reaction is equal to the rate of backward reaction and it is represent as:

A + B ⇄ C + D, where

A & B are reactants, and C & D are products.

As the rates are equal in equilibrium state, so the concentration of reactant and product also have constant value as there is no change in the rate.

Hence, option (B) is correct i.e. concentrations of the reactants and products have reached constant values.

To know more about chemical equilibrium, visit the below link:

https://brainly.com/question/13414142

Answer:

4.92 grams of sodium phosphate (Na₃PO₄) are required to make 125 milliliters of a 0.240 M.

Explanation:

Molarity is a measure of concentration that 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 the 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].

In this case:

Replacing in the definition of molarity:

[tex]0.240 M=\frac{number of moles}{0.125 L}[/tex]

Solving:

number of moles= 0.240 M*0.125 L

number of moles= 0.03 moles

Being the molar mass of sodium phosphate 164 g/mole, that is, the mass of one mole of the compound, you can calculate the mass of 0.03 moles using the following rule of three: if 1 mole of the compound has 164 grams, 0.03 moles contains how much mass?

[tex]mass=\frac{0.03 moles*164 grams}{1 mole}[/tex]

mass= 4.92 grams

4.92 grams of sodium phosphate (Na₃PO₄) are required to make 125 milliliters of a 0.240 M.

Answer:

2.1 M

Explanation:

The dilution equation is [tex]M_{s} V_{s} = M_{d} V_{d}[/tex].

[tex]M_{s}[/tex] = the molarity of the sock solution

[tex]V_{s}[/tex] = the volume of the sock solution

[tex]M_{d}[/tex] = the molarity of the diluted solution

[tex]V_{d}[/tex] = the volume of the diluted solution

The stock solution would be what is doing the diluting, so "175 mL of a 3.00 M solution". So [tex]M_{s}[/tex] = 3.00 M. Then: Converting 175 mL to liters: [tex]175 mL * \frac{1 L}{1000mL} = 0.175 L[/tex] (This is [tex]V_{s}[/tex])

And converting 250 mL KCl to liters: [tex]250 mL * \frac{1 L}{1000mL} = 0.250 L[/tex] (This will be [tex]V_{d}[/tex])

Then, we plug in our given into the dilution equation, resulting in:

[tex]3.00 M * 0.175 L = M_{d} * 0.250 L[/tex] (divide both sides by 0.250 L, in order to get [tex]M_{d}[/tex] by itself)

[tex]\frac{3.00 M * 0.175 L}{0.250 L} = M_{d}[/tex]

[tex]M_{d} = 2.1 M[/tex]

So, the molarity of 250 mL KCl made by diluting 175 mL of a 3.0 M solution would be 2.1 M (mol/L).

Hopefully this helped you understand the topic a little bit better. I just finished molarity and dilutions in Chemistry last week. Good luck!

Answer:

I'd say 624.2^3 inches.

Explanation:

Answer:

im not sure go with the first

Explanation:

Answer:

Photosynthesis in plants converts solar energy into chemical energy using electrons and protons from water. in plants involves a series of steps and reactions that use solar energy, water, and carbon dioxide to produce organic compounds and oxygen.

Explanation:

Answer:

its is used to make sugar which plants eat think it goes through like glycose or something

Explanation:

Answer:

The law of conservation of energy states that the total energy is constant in any process. Energy may change in form or be transferred from one system to another, but the total remains the same.

Could you please help me with the two most recent questions of mine on my page? I will give u brainliest and 20 points! :))) X

Answer:

the answer is 4

Explanation:

your welcome lol

Answer:

A.

Explanation:

You should NEVER eat or drink anything in a lab area. You never know what chemicals or gases are in the lab, and they can harm you.

Wearing a drawstring hoodie won't protect you from chemicals.

Don't wait to clean up chemicals, immediately get a teacher and clean it up (follow the teachers instructions). You never know what has spilled, and if it is harmful or not, or if there is a certain procedure to clean it up.

Don't change the equipment in the middle of an experiment. This can tamper with your results, and depending on what you are working with, this can be dangerous.

Answer:

1.  Solubility will increase, because as T increases the − Δ H ∘ R T −ΔH∘RT term becomes smaller therefore K will get larger.

2. To ensure the dissolution process was at equilibrium.

Explanation:

Given that;

ΔG°= -RTlnK

and

ΔG° = ΔH° - TΔS°

So;

-RTlnK = ΔH° - TΔS°

lnK = ΔH°/-RT - TΔS°/-RT

lnK = -(ΔH°/RT) + ΔS°/R

K = e^-(ΔH°/RT) + ΔS°/R

Hence, Solubility will increase, because as T increases the − Δ H ∘ R T −ΔH∘RT term becomes smaller therefore K will get larger.

2.

Since solubility is an equilibrium process, it means that some undissolved solute must be present in order to determine the solubility product correctly.

Solubility is the ability of the solute to dissolve in the solution. As temperature increases, the solubility increases, and the presence of solid ensure dissolution.

The Gibbs free energy is the change in the energy of a system from the energy present in the reactant towards the product formation.  

It is given as,

[tex]\rm \Delta G^{\circ}= \rm -RTlnK \\\\\rm \Delta G ^{\circ} = \Delta H ^{\circ} - T\Delta S ^{\circ}[/tex]

Equating both equations we get:

[tex]\begin{aligned} \rm -RTlnK &= \rm \Delta H ^{\circ} - T\Delta S ^{\circ}\\\\\rm lnK &=\rm -(\dfrac{\Delta H ^{\circ}}{RT}) + \dfrac{\Delta S ^{\circ}}{R}\\\\\rm K &=\rm e^{-(\frac{\Delta H ^{\circ}}{RT}) + \frac{\Delta S ^{\circ}}{R}}\end{aligned}[/tex]

Thus, the solubility of the substance increases with an increase in temperature.

The solubility product is estimated correctly by the equilibrium process that ensures the presence of the undissolved solute particles.

Therefore, 1. option A. solubility increases and 2. option B. to ensure the equilibrium process are the correct options.

Learn more about solubility here:

https://brainly.com/question/14092287

Answer:

I would choose E

Explanation:

Chemical reactions occur when chemical bonds between atoms are formed or broken. The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products

web-

Answer:

c

Explanation:

this is because it makes sense

Answer:

d

Explanation:

The answer is 2Hz

To calculate frequency, divide the number of times the event occurs by the length of time.

Answer:

0.01125

Explanation:

:b