A student stops a titration BEFORE theequivalence point is reached. If NaOH isbeing added to an unknown acid, HA, whations are present in the clear solution in theflask?A. H+, A-, Na+, OH-B. A-, Na+, OH-C. A-, Na+ and H+

5.57 grams

Given the reaction between sodium and oxygen expressed as:

Given the following parameters

Mass of sodium = 16.0g

Determine the moles of sodium

According to stoichiometry, 4 moles of sodium reacts with 1 mole of oxygen, the moles of oxygen that reacted is given as;

Determine the mass of oxygen that reacted

Hence the mass of oxygen that reacted is 5.57 grams

Some oxidation number rules

1) The oxidation number of a free element is always 0. The atoms in He and N2, for example, have oxidation numbers of 0.

2) The usual oxidation number of hydrogen is +1.

3 The oxidation number of oxygen in compounds is usually -2. Exceptions include OF2 because F is more electronegative than O, and BaO2, due to the structure of the peroxide ion, which is [O-O]2-.

a) HF, H = +1 F = -1

b)

c) H₂0, H = +1 O = -2

d) Pl3, P = +3 I = -1

e) CS₂, C = +4 S = -2

f) Na₂O₂, Na = +1 O = -1

g) H₂CO3 H = +1 C =+4 O =-2

h) NO2 N = +2 O = -2

i) SO2-4 S =+6 O = -2

13.1% m/v is  the mass percent by volume of 44.1 g of glucose (C₆H₁₂O₆, MM = 180.2 g/mol) in 325 mL of solution.

[tex]% m/v=mass solute/volume solution * 100%=42.6g/325mL *100%=13.1%m//v[/tex]% m/v = mass solute/volume solution x 100%

[tex]% m/v=mass solute/volume solution * 100%=42.6g/325mL *100%=13.1%m//v[/tex]% m/v =44.1g/325 mL x 100%

[tex]% m/v=mass solute/volume solution * 100%=42.6g/325mL *100%=13.1%m//v[/tex]% m/v =13.1% m/v

An object's volume in three dimensions is determined by the area encompassed inside its boundaries. It is also known as the object's capability on occasion. Calculating how much is required to fill an object can be done using its volume; for example, how much water is required to fill a bottle, aquarium, or water tank.

The most fundamental and typical kind of three-dimensional form is a sphere. Spheres are frequently seen as balls, globes, holiday lights, oranges, etc.

To know more about  volume  visit :https://brainly.com/question/24189159

#SPJ1

6.5 moles of gas will fill 1.7 litres at 1.3 atm at the temperature (in K). 546atmK273K=P, and 1atm273K = P.

Temperature is a measurement used to represent hotness and coolness on any of a number of scales, including Fahrenheit or Celsius. According to temperature, heat energy will naturally move from a hotter (body with a high temp) to a cooler (body with such a lower temperature) (one at a lower temperature).

The scrotum is the area of the body with the highest temperature (37°C), following by the ears, urine, as well as the mouth. The coldest temperature on human body that can usually be measured is the armpit (35.9°C).

To know more about temperature visit:

https://brainly.com/question/19572385

#SPJ13

Explanation:

We are given: density of promethazine = 25mg/mL

: mass of promethazine = 15.0mg

Answer:

The nurse will draw up 0.60 mL.

The question requires us to describe a dehydration reaction.

In chemistry, a dehydration reaction is defined as a chemical reaction that involes the loss of water from the reactant. In other words, a dehydration reaction happens when the water molecule is formed from the one (or two combined) reactant.

First, we write our reaction:

We call solubility to "S"

LaF₃(s) → La³⁺(aq) + 3 F⁻(aq)

Initial - 0.055M (LaCl3) 0

Change +S +3.S

Eq. 0.055+S 3.S

Ksp = 2×10^−19 = [La³⁺]x[F⁻]³ = (0.055+S)x(3.S)³

2×10^−19 = (0.055+S)x(3.S)³ => S = 5.12x10^-7 mol/L x (195.9 g/mol) =>

S = 1.00x10^-4 g/L

(195.9 g/mol = The molar mass of LaF3)

Answer: S = 1.00x10^-4 g/L

We have the ethanol combustion reaction to produce CO2 and water. The balanced equation of the reaction is:

We must first find the moles of ethanol corresponding to 421 grams. To do this we divide the mass by the molar mass of ethanol. The molar mass of ethanol is: 46.07g/mol. The moles of ethanol will be:

Now, by the stoichiometry of the reaction, we see that the Oxygen to Ethanol ratio is 9/4. So, the moles of oxygen needed will be:

We find the grams of oxygen by multiplying the moles by the molar mass. The molar mass of O2 is 31.9988g/mol.

Answer: To complete the combustion of 421 g of ethanol are needed 658 grams of oxygen

In chemistry, reduction means any of a class of chemical reactions in which the number of electrons associated with an atom or a group of atoms is increased.

You can say that a compound that is gaining electrons is being reduced.

The situation where the reduction is occurring is:

When the reduction occurs, the oxidation number (which is the superindex), it seems that is reducing this number. In this case, 2+ become 1-.

Remember: when the oxidation number is reducing, it means that the compound or element is a reduction (gaining electrons) and when the oxidation number is increasing, it means that it is oxidation (losing electrons) such as the other cases of the problem.

Answer

Explanation

Given unbalanced equation:

NH₃ + O₂ → ___NO₂ + _H₂O

Step 1: Balance the N atom on both sides by putting 4 as the coefficient of NH₃ and NO₂ on the reactant and product sides of the equation respectively.

4 NH₃ + O₂ → 4 NO₂ + _H₂O

Step 2: Balance the H atom on both sides by putting 4 as the coefficient of NH₃ and NO₂ on the reactant and product sides of the equation respectively.

Explanation:

A chemical property is one in which atoms are rearranged in the process.

-----------------

Q) In this case, this is a chemical property because hydrogen starts being consumed when the flask is heated and hydrogen combines with the solid too.

Chemical

-----------------

M) This is a physical property because nothing happens to the atoms of the different substances in the sample. The metallic particles from the sample are removed with the magnet.

Physical

----------------

C) This is chemical property because a reaction is carried out inside.

Oxygen reacts with X

Chemical

Answer:

Atom 1 and Atom 4 of the elements below are in the same group in the periodic table.

1) Boiling point - It is easy to observe the boiling point of a substance because it is only a physical process, raising the temperature enough to get to its boiling point.

2) Flammability - Observing the flammability of a substance has the effect of decomposing the substance because of the combustion, therefore its identity is not preserved.

3) Density - We can observe the density of a substance without changing its identity since it is just the relation between mass and volume.

Reactivity - The way to observe the reactivity of a substance is by undergoing a reaction with it, resulting in products that differ from the initial substance, so it is not possible to observe reactivity without a change in the substance.

Final answer: Boiling point and density can be observed without a change in the identity of a substance

Step 1

The reaction provided:

Zn + S => ZnS (completed and balanced)

-------------------

Step 2

Information provided:

2.50 moles of Zn

1.00 mole of S

--------------------

Step 3

The limiting reactant limits the amount of product formed.

By stoichiometry, procedure:

Zn + S => ZnS

1 mole Zn ------------- 1 mole S

2.50 moles Zn -------------- X

X = 2.50 moles Zn x 1 mole S/1 mole Zn = 2.50 moles S

For 2.50 moles of Zn, 2.50 moles of S are needed but there is only 1.00 mole of S. Therefore, the limiting reactant is S.

Answer: Sulfur (S)

Calculations:

We are given the following parameters :

• Mass = 2.55kg = 2.55*1000= 2550

• T1 = 21°C

• T2 = 37°C

• Specific heat of water = c = 1cal/g°C

We will calculate q (heat ) as follows :

Explanation:

Step 1 - We need to rewrite the equation here:

4NH3+5O2 --> 4NO+6H2O

The ratio between ammonia (NH3) and the products are:

NH3 and NO:

4:4

NH3 and H2O:

6 H2O

So if we have 1.2 moles of ammonia:

1.2 moles of NH3 ---- x moles of NO

4 moles of NH3 ---- 4 moles of NO

x = 1.2 moles of NO

1.2 moles of NH3 --- x moles of H2O

4 moles of NH3 --- 6 moles of H2O

4x = 7.2

x = 7.2/4

x = 1.8 moles of H2O.

Answer: The total number of moles of products formed is 1.2 moles of NO and 1.8 moles of H2O.

Answer:

Explanation:

Here, we want to get the percentage by mass of the water molecules in the given compound

To get this, we have to divide the molar mass of water by the molar mass of the percentage and write the answer as a percentage

The molar mass of water is 18 g/mol

The molar mass of MgCO3 is 84 g/mol

Thus, the percentage by mass of water will be:

From the chemical equation we see that 1 mole of diborane (B2H6) will produce 2 moles of water.

We will firstly calculate the moles of diborane:

One mole of diborane produces 2 moles of water then to find the moles of water that is produced we:

We then convert the moles of the water to mass:

Mass of water is 4.824g

ANSWER

The molarity of the solution is 0.25M

EXPLANATION

Given that;

The mole of NaOH is 2.5 mol

The volume of the solution is 10.0L

Follow the steps below to find the molarity of the solution

The molarity formula is given below as

Substitute the given data into the above formula

Therefore, the molarity of the solution is 0.25M

Answer

A. ethyl butanoate

Explanation:

Esters are known for their distinctive odors and are commonly used for food aroma and fragrances. The general formula of an ester is RCOOR'.

Esters are formed through reactions between an acid and an alcohol with the elimination of water.

Esters are named as if the alkyl chain from the alcohol is a substituent. No number is assigned to this alkyl chain. This is followed by the name of the parent chain from the carboxylic acid part of the ester with an –e remove and replaced with the ending –oate.

Hence, the name of the given ester is:

A. ethyl butanoate

Answer

Number of moles = 0.0025 mol

Step-by-step explanation:

Given that,

The volume of He at STP is 56.0 ml

Part a:

Find the mole

According to the standard conversion

1 mol = 22.4L

Firstly, we need to convert 56.0ml to L

This can be done by dividing by 1000

56.0mL = 0.056L

1 mole = 22.4L

x mole = 0.056L

Cross multiply

1 * 0.056 = x * 22.4

0.056 = 22.4x

Divide both sides by 22.4

x = 0.056 / 22.4

x = 0.0025 mole

Hence, the mole of Helium is 0.0025 moleHe

We are asked to find some characteristics of phosphorus. We start with the yu period group to which they belong in the periodic table. This information is found in the periodic table of elements.

Looking in the periodic table we find that phosphorus P is located in group VA (15) and in period 3.

The electronic configuration depends on the number of electrons of the element. Phosphorous has 15 electrons. We have an ion P^3-, this ion has three more electrons, so for this element, we will have 18 electrons. The electronic configuration will be:

The short notation depends of another element, in this case of Ne, so the shot notation will be:

The valence level is the last energy level, we see that the greatest coefficient is 3, so the valence level is 3

In summary, we have that the answer will be:

Orbital Diagram: Drawn in the picture

Long Notation: 1s2 2s2 2p6 3s2 3p6

Short Notation: [Ne] 3s2 3p6

Valence Level: 3

Group on Periodic Table: 15 or VA

Period on Periodic Table: 3

The question requires us to calculate the energy of a photon given that its frequency is 7.87 × 10^15 Hz.

To calculate the energy of a photon, we can use the following equation:

where h is the Planck's constant (6.626 x 10^-34 Jxs) and f is the frequency (in Hz or 1/s). (Note that the unit Hz is equivalent to s^-1)

Then, applying the frequency provided and the Planck's constant to the equation, we have:

Therefore, the energy of the photon is 5.21 x 10^-18 J.

For the generation of oxygen gas, hydrogen peroxide is generally used and by means of a catalyst, the peroxide is decomposed into two compounds: Liquid water and oxygen gas. The reaction is as follows:

Word equation

Hydrogen peroxide --->Water + Oxygen

Formula equation

It is important to note that the reaction needs a catalyst.

The number of grams in 0.2 moles of water is 3.602grams.

The mass of a substance can be calculated by multiplying the number of moles of the substance by its molar mass as follows:

Mass = molar mass × no. of moles

According to this question, there are 0.2 moles in water. Water has a molar mass of 18.01g/mol. The mass can be calculated as follows:

Mass = 0.2 moles × 18.01g/mol

Mass = 3.602grams.

Therefore, 3.602 grams is the mass of the water molecule.

Learn more about mass at: https://brainly.com/question/16386473

#SPJ1

Francium easily loses electrons than cesium

Both Cesium and Francium are Group 1 elements (Alkali metals). This shows that the elements in this group have one valence electron in their outermost shell and can easily lose this electron to form a stable atom.

According to the element in the group, Lithium has the least tendency to loose its valence electron while Francium has the highest tendency to lose its valence electron because its outermost electron gets further from the positive nucleus and less attracted by the nucleus compared to the Caesium element.

Also, the atomic size of Francium is greater than that of Caesium. This also shows that francium easily loses electrons than cesium

The energy of the  1 photon of the light with the wavelength of the most energetic line is 6.9 * 10^-19 J.

We know that a photon can only be explained as simply as possible as a bundle of light. The photon is emitted from an atom when an electron in the atom is seen to move from a higher to a lower energy level thereby emitting light of the appropriate wavelength.

Now we can see that the wavelength that is the shortest is the one that would have the greatest energy. This is because the energy of the photon is inversely proportional to the energy of the photon.

Now we have';

Wavelength of the photon = 285.2 nm or 285.2 * 10^-9 m

Speed of light = 3 * 10^8 m/s

Plank's constant = 6.6 * 10^-34 J/s

Then;

E =  6.6 * 10^-34 J/s * 3 * 10^8 m/s/ 285.2 * 10^-9 m

E = 6.9 * 10^-19 J

Learn more about wavelength:https://brainly.com/question/13533093

#SPJ1

We have a reaction between potassium oxide and water. They already present us with the chemical equation but we must balance it.

For this we add the coefficient two in front of the KOH molecule, in this way we will have on each side of the reaction:

K--->2 atoms

O---> 2 atoms

H---> 2 atoms

So, the chemical balanced equation will be:

The subscript "s" refers to the solid state, "l" to a liquid state, and "aq" to a solution of the solute in water.

The initial temperature of water can be calculated from the heat energy using calorimetric equation. The initial temperature is obtained as 18.65 °C.

Calorimetry is an analytical tool used to determine the heat energy absorbed or released in a chemical reaction. The heat  energy q, mass of the substance m and the specific heat capacity c with a temperature difference ΔT is written as follows:

q = m c ΔT.

Here, the heat energy required for raising the temparture of 125 g of waater to 45 °C is 13750 joules . Then, the initial temperature be x, then x can be calculated as follows:

13750 J  = 125 g × 4.18 J/g °C × (45 - x °C)

     x =   45 -  [ 13750 J / (125 g × 4.18 J/g °C) ]

        = 18. 65 °C.

Therefore, the initial temperature was 18. 65 °C.

To find more on calorimetry, refer here:

https://brainly.com/question/11477213

#SPJ1

We have a change of pressure and temperature. To solve and find the new pressure we will assume that the volume and moles of the gas remain constant, therefore we can apply Gay-Lussac's law which tells us:

Where,

P1 is the initial pressure of the gas, 954atm

T1 is the temperature of the gas, 728K

T2 is the final temperature, 951K

P2 is the final pressure, =?

We clear P2 and replace the known data:

Answer: The new pressure will be 1246atm