Ascorbic acid (vitamin C, C6H8O6) is a diprotic acid (Ka1 = 8.0×10^–5 and Ka2 = 1.6×10^–12). What is the pH of a 0.240 M solution of ascorbic acid?

This is a stoichiometry problem, where we have an initial amount of reactant and we need to find out how much of the product will we end up with, in order to do that we need to:

1. Set up the properly balanced equation, which the question already provided us

2 KClO3 -> 2 KCl + 3 O2

2. Check the molar ratio between the two compounds, which is 2:3, 2 moles of KClO3 will produce 3 moles of O2, but we have 3 moles of KClO3

2 KClO3 = 3 O2

3 KClO3 = x O2

x = 4.5 moles of O2 will be produced from 3 moles of KClO3

3 KClO3

2 KClO3/ 3 O2

4.5 O2

Answer:

Explanation:

Here, we want to identify the elements in BeSO4 in their standard state as the reactants and BeSO4 as the product

From what we have, there are 4 atoms of oxygen, 1 atom of Beryllium, and 1 atom of sulfur

In their standard state, oxygen is a gas, Berrylium and Sulfur are solids

The number of elements atom on the reactant side must be equal to that on the product side

Thus, we have the correct choice of answer as E

In order to properly balance an equation, we need to make sure that the same amount of elements on the reactants side matches the number of elements on the products side, we can do that by increasing the number in front of each molecule, the so called stoichiometric coefficient. In the reaction from the question we can properly balance by adding the following stoichiometric coefficients

For our question, we have:

2 Al + 3 Zn(NO3)3 -> 2 Al(NO3)3 + 3 Zn

Now this reaction is properly balanced

Al(NO3)3 has the coefficient 2

To calculate the molar mass of NaHCO₃, we need to add the molar mass of each of its atoms.

This compound has 1 atom of Na, 1 of H 1 of C and 3 of O.

The molar mass of these atoms can be consulted on a periodic table, and they are:

So, the molar mass of NaHCO₃ is:

It can lower and expand the melting point if the sample is not dried completely.

Impurities may be present in a sample if the drying process is not complete. The melting point is decreased and widened when contaminants are still present in a sample. For instance, if a substance's usual melting point range is 104C to 106C, improper drying could result in the presence of impurities, which would lower and widen the melting point range to something like 85C to 97C.

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Explanation:

Ammonia will decompose into nitrogen gas and hydrogen gas according to the following reaction. In that reaction 92 kJ will be absorbed.

2 NH₃ ----> N₂ + 3 H₂ ΔH = 92 kJ

Since the heat is absorbed, the sign is positive and we can add it to the reactants side.

2 NH₃ + 92 kJ ----> N₂ + 3 H₂

When 92 kJ are absorbed 34 g of ammonia are reacted. We can use that relationship to find the mass of ammonia that reacted when 184 kJ where absorbed.

34 g of NH₃ : 92 kJ

mass of NH₃ = 184 kJ * 34 g of NH₃/(92 kJ)

mass of NH₃ = 68 g

Answer: 68 g of ammonia were decomposed.

2 NH₃ ----> N₂ + 3 H₂ ΔH = 92 kJ

Answer

1.775 M

Explanation

Given:

Volume of solution, V = 400.0 mL

Mass of NaCl = 45.5 g

What to find:

The molarity of the solution.

Step-by-step solution:

Step 1: Convert the volume from mL to L.

This can be done by dividing the volume in mL by 1000.

V = 400.0 mL = (400.0/1000) = 0.4L

Step 2: Convert the mass of NaCl to moles.

The mass can be converted to moles using the mole formula below:

From the periodic table, the molar mass is determined to be = 58.44 g/mol

Putting mass = 41.5 g and molar mass = 58.44 g/mol into the formula, we have:

Step 3: Calculate the molarity of the solution using the molarity formula.

Molarity formula is given by:

Moles= 0.7101 mol and V = 0.4 L

Therefore,

The molarity of a 400.0 mL solution that contains 41.5 g of NaCl = 1.775 M.

The Lewis structure tells us how atoms are bonded and shows the valence electrons of each element as dots. These valence electrons can be found in the periodic table of the elements, and they coincide with the group number to which the element belongs.

So phosphorus (P) belongs to group 5 and has 5 valence electrons. Chlorine (Cl) is in group 7 and has 7 valence electrons.

The Lewis scheme will be:

The blue dots correspond to the valence electrons of phosphorus, and the purple dots are the electrons of chlorine. The electrons they share can be written with a line.

We have that the geometry of the molecule will be:

Four sp3 type hybrid orbitals are formed, three of which overlap with each of the Cl atoms and the other houses the lone electrons. Sigma type bonds.

Answer: 4 sp3 hybrid orbitals

We must first determine the heat needed to heat 175mL of water. In the working temperature range we can assume that the density of water is 1g/mL, so the mass of water that we must heat will be 175g of water.

Now, the heat we need to heat that mass of water is calculated with the following equation:

Where Q is the heat required to heat the water

Cp is the specific heat of water equal to 4186 J/g°C

delta T is the change of temperature = 25°C-20°C=5°C

We replace the know values:

Now, to heat the water they tell us that the glucose combustion will take place. We must assume that all the heat generated in the reaction will go to heating the water and that there is no heat loss to the environment.

The combustion reaction of glucose generates 2538.7 kJ/mol. So the moles of glucose needed will be:

We calculate the grams of glucose by multiplying the moles by the molar mass of glucose equal to 180.2g/mol

grams of glucose= 1.44 mol x 180.2 g/mol=260g

Answer: To heat 175 mL of water from 20.0 °C to 25.0°C are required 260g of glucose

DNA describes as a blueprint for a cell because it contain the instruction needed for an organism to grow develop and survive

DNA is called a blueprint of life because it contain the instruction needed for an organism to grow develop and survive and reproduce and DNA does this by controlling protein synthesis and protein do must of the work cell and are basic unit of structure and function in the cell of organism

DNA is read by the enzyme RNA polymerase and this enzyme attaches itself to the DNA strand slightly in front of a gene and it then slides along the DNA strand making a copy of the gene only using RNA building blocks instead of DNA building block

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2. (a) We are told that it is a double displacement reaction, so there will be two substitutions and Cl will exchange places with NO3.

Now, that will be the full reaction but we need to balance it. Count the atoms of each element on each side of the reaction. In the figure we can see that Chlorine, Nitrogen and Oxygen are not balanced.

We place the coefficient 2 in front of the AgCl molecule to balance the chlorides. You can see the picture.

Now we will balance the nitrogens. There are two nitrogens in the products. We place the coefficient two in the AgNO3 molecule. In the figure I will make the update.

Now the equation is balanced, so the balanced reaction will be:

option A is  is a true molecular equation depicted.

Na2S+2HCl→2NaCl+H2S↑

A molecular equation is a balanced chemical equation in which the constituent ions of the ionic compounds are represented as molecules. Each of a compound's constituent components and the amount of atoms they each possess are listed in the molecular formula. Similar rules apply to the most basic formula: all the constituents are mentioned, but the numbers represent their relative proportions.

There are three different types of equations that may be developed for a reaction involving ionic compounds: molecular equations, full ionic equations, and net ionic equations. In chemistry, each of these equations has a specific function. Because it details exactly which compounds were employed in a process, a molecular equation is useful.

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Step 1 - Understanding % concentration in mass

% concentration in mass expresses the concentration of a solute by its percentage, in mass, in relation to the total mass of the solution.

Mathematically, we can find this percentage by the following relation:

Step 2 - Caculating the % concentration for the given solution

According to the exercise:

Setting these values in the equation:

Answer: the % concentration of NaCl in this solution is 3.38%.

Answer:

Explanation:

Here, we want to get the volume of NH3 that will react with 30L of NO at STP

From the question, we have it that 4 moles of ammonia reacted 6 moles of NO

Thus, we have the mole ratio as 6 to 4

Thus, the volume of ammonia reacted would be:

ANSWER

False

EXPLANATION

Electron affinity is defined as the energy released by adding an electron to an isolated gaseous atom

Neon has the electronic configuration of 2, 8, This implies that it belongs to period 2 and group 8

Recall, that Neon is a noble gas. Noble gases do not accept or release electrons.

Hence, neon does not have the tendency to accept or release electrons.

Neon as a noble gas has a large positive value for electron affinity

Therefore, the statement is not TRUE

Considering the ideal gas law, the pressure in a 7.00 L tank with 1.73 grams of hydrogen gas at 375 K is 26.5987 atm.

An ideal gas is called a hypothetical or theoretical gas, which would be composed of particles that move randomly and without interacting with each other.

An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar gas constant:

P×V = n×R×T

In this case, you know:

Replacing in the definition of ideal gas law:

P× 2 L = 1.73 moles ×0.082 atmL/molK ×375 K

Solving:

P= (1.73 moles ×0.082 atmL/molK ×375 K)÷ 2 L

P= 26.5987 atm

Finally, the pressure is 26.5987 atm.

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Given the equation:

• Sn (NO2)4 + Pt3N4 → Sn3N4 + Pt(NO2)4

(1) The first thing we noticed is that this is a double replacement equation

• ,Sn combines with N4 to form Sn3N4, (,take note that Sn→ Sn3,)

• Pt3 combines with (NO2) to form Pt(NO2)4 ( ,take note that Pt3 → Pt)

(2) Balancing the equation

• Sn (NO2)4 + Pt3N4 → Sn3N4 + Pt(NO2)4 ....(,place 3 infront of Sn in the reactant side .)

• 3,Sn (NO2)4 + Pt3N4 → Sn3N4 + Pt(NO2)4...( ,then place 3 infront of Pt in the product side,)

• 3,Sn (NO2)4 + Pt3N4 → Sn3N4 + ,3,Pt(NO2)4

Check :

3Sn reactant : Sn3 Product

(NO2)4 reactant : (NO2)4 product

Pt3 reactant : 3Pt product

N4 reactant : N4 product

Based on the mole ratio from the chemical reaction 3 moles of Br2 produces 2 moles of AlBr3. We can set this equation up to determine the unknown:

3.3 moles of Br2 is needed to reacts with 5 mol of AlBr3.

Answer: By using Ideal gas law  PV=nRT  ,the final pressure is calculated

Explanation:

In thermodynamics a constant volume process is known as isochoric process and in this volume remains constant and pressure varies along with the temperature .

FORMULA USED - PV=nRT

If Volume is constant ,then  initial Temperature  = 18+273 = 291K

final temperature =225K

initial pressure = 0.90 atm

final pressure = ?

The final pressure comes out to be 0.6958 atm.

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In the process that they describe to us, a mixture initially occurs between these two liquids, when they are mixed, a chemical reaction occurs and one of the products obtained is not soluble in the liquids, therefore a precipitate will form. This type of reaction is called a precipitation reaction.

Therefore, the answer will be:

C) Have gone through a chemical reaction in which a new substance called a precipitate was produced

Answer

c) C₈H₁₈

Explanation

Given that:

A compound has a molecular weight of 114.22 g/mol

The empirical formula for the compound is C₄H₉

What to find:

To determine the molecular formula for the compound.

Step-by-step solution:

(Empirica formula)n = (Molecular weight)

(C₄H₉)n = 114.22

(4 x 12.01 + 9 x 1.01)n = 114.22

(48.04 + 9.09)n = 114.22

57.13n = 114.22

Divide both sides by 57.13

n = 114.22/57.13

n = 2

Therefore, the molecular formula for the compound is (C₄H₉)₂ = C₈H₁₈

The correct answer is option c) C₈H₁₈

Answer:

I believe it is

C. density

Explanation:

have a nice day!❀

Explanation:

The % w/v s the number of grams of solute in 100 mL of solution

So it relates grams of solute with mL of solution.

Answer: B. grams and milliliters

To answer this question, the first step is to convert the given number of molecules to moles using Avogadro's number:

Now, use the molecular weight of CO2 to find the mass of this amount of moles:

The mass of 5.32x10^22 molecules of CO2 is 3.872g.

The free energy of formation of the MgO is −597 kJ/mol.

We know that the free energy of formation is defined as the energy that is evolved or absorbed when a substance is formed from its components under standard conditions. In this case, we have that the magnesium and the oxygen are all pure substances.

It is important that we recall that the free energy of formation of a pure substance is zero. We have the free energy  of formation of the magnesium oxide as−597 kJ/mol.

Hence;

Sum of free energy of formation of products - Sum of free energy  of formation of reactants

We have;

(−597 kJ/mol) - (0  kJ/mol)

free energy of formation = −597 kJ/mol

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To solve this question, we need to know the molar mass of Ca. It is 40 g/mol

There are 3 atoms of Ca in Ca3(PO4)2

So the mass of Ca in Ca3(PO4)2 is 3x40 = 120 g

So:

375 grams ---- 100%

120 g --- x

x = 32%

Answer: 32% of calcium.

Answer:

Balls uhhh neutron but if theres a better answer take it cuz im prolly wrong

Explanation:

50/50 im right up to you to take the chance or jus search it on tha goog

If 5750 J of energy are added to 455 g of granite at 24 °C. The final temperature of granite is 39.9 °C

Given that :

heat energy = 5750 J

mass of granite = 455 g

initial temperature = 24 °C

specific heat capacity = 0.12 cal / g °C = 0.790 J/ g °C

the expression for the heat capacity is given as :

Q = mcΔT

5750 J = 455 g × 0.790 J/ g °C ( T - 24 °C)

5750 = 359.45 T - 8626.8

T = 39.9 °C

if 5750 J of energy are added to 455 g of granite at 24 °C. The final temperature of granite is 39.9 °C

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5s. Option D is correct

Electron orbitals are area around the nucleus where electron resides. The closer the orbital to the nucleus, the higher the energy level.

Based on the explanation above, 5s will be higher in energy than the 4d orbital.

0.268grams

According to the Avogadro's constant

1 mole of an atom = 6.02 * 10^23 molecules

Given the following

atoms of calcium = 4.02 x 10^21 atoms

Determine the moles of calcium

Determine the mass of Calcium

Hence the required grams in 4.02 x 10^21 atoms of calcium is 0.268grams