- a) write the formula unit of calcium fluoride.


b) A certain mass m of calcium fluoride contains 1.2*1023 anions. Deduce the mass (m). NA= 6.02*1023

The correct answer is option B: 7

When the following equation is balanced, the coefficients are 7.

According to the law of conversation of mass, matter is neither created nor destroyed, it only transforms form one phase to another.

First of all, write the unbalanced chemical equation.

N\(H_{3}\)(g) + \(O_{2}\)(g) → N\(O_{2}\)(g) + \(H_{2}\)O(g)

Now, split the reaction in half and try to balance the number of atoms on each side of the chemical reaction.

After that add appropriate coefficients to balance the atoms on either side.

In the chemical equation, electron gain and lost must be equal.

At last, to balance the coefficients of all the species, multiply with a whole number or integer.

Now if we choose the following coefficients i.e. 4, 7, 4, 6 on both sides of the equation, we see the equation becomes:

4\(NH_{3}\)(g) + 7\(O_{2}\)(g) → 4N\(O_{2}\)(g) + 6\(H_{2}\)O(g)

To verify, always check that the equation has same number of atoms on either side.

If you want to learn more about coefficients click here:

https://brainly.com/question/24881460

#SPJ4

If one form of a gene can mask the appearance of another form, that form is considered dominant over the other form. Option B.

According to Mendel, genes are usually made up of 2 alleles. These alleles can be the same or different. When the alleles are the same, the gene is said to be homozygous. If the alleles are different, the gene is said to be heterozygous.

When the two alleles that make up a gene are different, one will be dominant and the other will be recessive. The dominant gene masks the effect of the recessive gene. In other words, the recessive gene cannot be expressed as long as it coexists with the dominant gene. In order for it to be expressed, it has to be in two copies or a homozygous recessive form.

For the dominant allele, however, only one copy is needed for it to be expressed.

In summary, if one form of a gene can mask the appearance of another form, that form is considered dominant over the other form.

More on genes can be found here: https://brainly.com/question/5519888

#SPJ1

Answer:

3. Triple Beam Balance

Explanation:

A triple beam will be most suitable for measuring the mass of a small stone because it is very accurate, and has a reading error of +/- 0.05 gram.

Answer:

Explanation:

Neils Bohr in 1913 put forward his own model of the atoms based on the quantum mechanics originally developed by Planck.

Answer:

It showed that electrons could jump from one path to another

Explanation:

quiz

Crystallization of sugar in a syrup can be avoided by adding inverted sugar. Invert sugar is a mixture of glucose and fructose, produced from sucrose. It is produced by hydrolysis of sucrose by heating with water and an acid such as lemon juice, vinegar or cream of tartar.

By adding invert sugar to a syrup, it reduces the amount of sucrose present in the solution and promotes the formation of glucose and fructose. This causes the solution to become more saturated and the syrup less likely to crystallize. Invert sugar is often used in the production of confectionery, ice cream, and other sweets.Inverted sugar can also be used to improve the texture and quality of baked goods. It is often used in cake recipes to enhance the flavor and increase the shelf life. It can also be used as a substitute for honey or corn syrup in recipes that require a liquid sweetener.In conclusion, the addition of invert sugar helps to prevent crystallization of sugar in syrup. Invert sugar is a mixture of glucose and fructose produced from sucrose by hydrolysis.

To know more about Crystallization visit :

brainly.com/question/32130991

#SPJ11

Answer:

Mass ratio:

a. Approximately \(51.2\%\).

b. Approximately \(35.3\%\).

c. Approximately \(43.2\%\).

Explanation:

Look up the relative atomic mass of each element on a modern periodic table:

For example, the relative atomic mass of \(\rm Al\) is \(26.982\). Hence, the mass of one mole of \(\rm Al\!\) atoms would be (approximately) \(26.982\; \rm g\).

Calculate the formula mass of \(\rm H_2O\):

\(\begin{aligned} & M({\rm H_2O}) \\ &= 2 \times 1.008 + 15.999 \\ &= 18.015\; \rm g \cdot mol^{-1}\end{aligned}\).

Calculate the formula mass for each of the hydrates:

\(\begin{aligned}& M({\rm MgSO_4 \cdot {7\, H_2O}}) \\ &= 24.305 + 32.06 + 4 \times 15.999 \\ & \quad\quad + 7 \times (2 \times 1.008 + 15.999) \\ &= 246.466\; \rm g \cdot mol^{-1}\end{aligned}\).

\(\begin{aligned}& M({\rm LiC_2H_3O_2 \cdot {2\, H_2O}}) \\ &= 6.94 + 2 \times 12.011 + 3 \times 1.008 + 2 \times 15.999 \\ & \quad\quad + 2 \times (2 \times 1.008 + 15.999) \\ &= 102.014\; \rm g \cdot mol^{-1}\end{aligned}\).

\(\begin{aligned}& M({\rm Al(NO_3)_3 \cdot {9\, H_2O}}) \\ &= 26.982 + 3 \times (14.007 + 3 \time 15.999) \\ &\quad \quad + 9 \times (2 \times 1.008 + 15.999) \\ &= 375.129\; \rm g \cdot mol^{-1}\end{aligned}\).

The mass of \(1\; \rm mol\) of \({\rm MgSO_4 \cdot {7\, H_2O}}\) formula units is \(246.466\; \rm g\).

There are seven mole of \(\rm H_2O\) formula units in that many \({\rm MgSO_4 \cdot {7\, H_2O}}\) formula units. The mass of that \(7\; \rm mol\) of \(\rm H_2O\!\) formula units would be \(7 \; \rm mol \times 18.015\; \rm g \cdot mol^{-1} = 127.105\; \rm g\).

Hence, the percentage mass of \(\rm H_2O\) in \({\rm MgSO_4 \cdot {7\, H_2O}}\) would be:

\(\begin{aligned}\frac{127.015\; \rm g}{246.466\; \rm g} \approx 51.2\%\end{aligned}\).

Similarly:

Explanation:

First, we need to rewrite the equation:

2K + 2H2O -> 2KOH + H2

This equation tells us that 2 moles of K react with 2 moles of H2O and produce 2 moles of KOH and 1 mole of H2.

If we have 43.7 grams of potassium, we can transform it into moles, compare with the ratio between Potassium and Hydrogen (H2) and then, calculate the quantity of hydrogen in grams.

So first, let's transform 43.7 grams of K into moles using the following formula:

moles = mass/molar mass

molar mass of K = 39.10 g/mol

moles = 43.7/39.10

moles = 1.12 moles

So:

2 moles of K --- 1 moles of H2

1.12 moles of K --- x moles of H2

2x = 1.12

x = 1.12/2

x = 0.559 moles of H2

Now let's transform moles into grams using the following formula:

mass = moles x molar mass

molar mass of H2 = 2.02 g/mol

mass = 0.559 x 2.02

mass = 1.13 g

Answer: It is produced 1.13 grams of H2.

Remember:

to balance equations in chemistry, you have to count the amount of atoms there are in a chemical eg:

the number of atoms in H20 are:

2 atoms of hydrogen

1 atom of oxygen (when there are no numbers by the letter it means that theres only 1 atom of it!)

The number next to a letter means the number of atoms thta it is made up of and atoms are the things it is made up of eg chocolate the ingredients are cocoa, milk and sugar ect so just like that CO2, H20 an ALL types of chemicals are made up of atoms. BUT WE WANT TO KNOW HOW MANY ATOMS- so u need to list these for all the 4 chemicals in the equation.

Im telling u this so that u can list out all of the atoms in each chemical (I will do the first two)

CH2=

1 atom of Carbon

2 atoms of hydrogen

O2=

2 atoms of oxygen

once u have listed out all the atoms from EACH of the chemicals in ur question (CH2, 02, CO2 and H20) categorise them like this

CH2

Carbon=........ Atoms

Hydrogen= .......Atoms

(Make sure the table is like vertical like lemme show u as an example. ATTACHED IS AN EXAMPLE OF WHAT UR WORK SHOULD BE SET OUT AS)

When you see the addition sign it means that elements like oxygen and hydrogen etc..basically add them up like CO2 + H20 theres oxygen in both so add up the atoms of oxygen FOR JUST CO2 AND H20 like  if there was one atom of oxygen in CO2 and 2 in h20 add them up and it makes three (1+2=3). 1 oygen  atom from CO2 plus 2 oxygen atoms in H20 that makes 3 atoms for both the chemiclas together (THIS WAS JUST AN EXMAPLE THERE ARENT ACTUALLY 2 ATOMS IN H20 OR 1 ATOM IN C02)

Look at the similarities OF ATOM NUMBERS like if CH2 has one atom of Carbon, CO2 ALSO has one atom of carbon which is fine BUT when it comes to differences u need to cross those out and PUT THAT NUMBER on both sides like if O2 has  2 atoms of oxygen and h20 has 1 that means that they need to be balanced like they either both need to be 1 atom or 2 atoms so for that u need to look attachment sorry u just need to cross them out and make them the same

make sure to write about what atoms are, to list out atoms for each chemical, compare the chemicals in both word chemicals and make them even!

Explanation:

The rate constant for a reaction generally increases with an increase in reaction temperature. The factor most sensitive to changes in temperature is the activation energy of the reaction.

The activation energy is the minimum energy required for a reaction to occur.

According to the Arrhenius equation, the rate constant (k) is directly proportional to the temperature (T) of the system. An increase in temperature would lead to an increase in the kinetic energy of the reactant molecules which will result in an increase in the number of effective collisions.

These effective collisions will have energy greater than the activation energy barrier, and thus they will lead to the formation of products. Hence, the rate of the reaction will increase with an increase in temperature.

Most of the reactions have a positive value of activation energy. Therefore, a slight increase in temperature can increase the rate of the reaction. However, if the temperature is increased beyond a certain limit, the rate of the reaction decreases due to the thermal denaturation of the enzyme or the inactivation of the catalysts, or the destruction of the reactants.

On increasing or decreasing the temperature the activation energy of a reaction changes drastically, either decreasing or increasing respectively.

In summary, the rate constant for a reaction is directly proportional to temperature and the activation energy is most sensitive toward temperature.

To know more about activation energy, refer here:

https://brainly.com/question/11334504#

#SPJ11

Yes, the reaction between methanol and oxygen to give formic acid and water is a redox reaction.

Redox reaction is an abbreviation for "reduction-oxidation" reaction. In a redox reaction, there is a transfer of electrons from one molecule to another molecule. The oxidation state of the reactants and products will change. Methanol is a reducing agent and oxygen is an oxidizing agent. Methanol reduces oxygen, and oxygen oxidizes methanol.

The reaction between methanol and oxygen to give formic acid and water is a redox reaction. In this reaction, methanol is oxidized to form formic acid, while oxygen is reduced to form water. The oxidation state of carbon in methanol goes from -2 in methanol to +2 in formic acid, indicating that it has been oxidized. The oxidation state of oxygen in oxygen goes from 0 to -2 in water, indicating that it has been reduced.

Therefore, this reaction involves both oxidation and reduction and is a redox reaction.

Learn more about redox reactions on:

https://brainly.com/question/21851295

#SPJ11

Universe, Stars, Planets, Asteroids

Answer:

Universe, Stars, Planets, Asteroids

Explanation:

When table salt (sodium chloride which ionizes into Na and Cl) is added to alginate, a gel does not form and spherification does not occur. This happens because the salt only has one positive charge that neutralizes the negative charge in the alginate.

There are various types of Spherification. Spherification is the creation of small spheres with a thin film on the surface and a liquid center. The process of spherification is mostly used in molecular gastronomy to make small, flavorful balls of liquid ingredients that burst in the mouth when bitten into. The method involves a process of encapsulating liquid droplets in a sphere made of a gel-like film. This process requires sodium alginate (E401), a gel-forming ingredient that thickens the liquids.

Sodium alginate gelation occurs as a result of the mixture of an alginate solution with a cation solution that causes the solution to gel. The sodium ions present in the solution swap with calcium ions present in the cation solution, causing a gel to form. This occurs as a result of a chemical reaction known as cross-linking. When table salt is added to the alginate solution, a gel does not form and spherification does not occur since the salt only has one positive charge that neutralizes the negative charge in the alginate. Alginate requires a doubly charged cation to cross-link.

Learn more about cations at https://brainly.com/question/14309645

#SPJ11

The volume of the balloon after he heats it to a temperature of 250.0°C is 0.718L.

The volume of a balloon at a particular temperature can be calculated by using the Charles law formula as follows:

V1/T1 = V2/T2

Where;

According to this question, a man heats a balloon in the oven. The balloon initially measures 0.402L with a temperature of 20.0°C. However, the volume of the balloon after he heats it to a temperature of 250.0°C can be calculated as follows:

0.402/293 = V2/523

523 × 0.402 = 293V2

210.25 = 293V2

V2 = 210.25/293

V2 = 0.718L

Therefore, the volume of the balloon after he heats it to a temperature of 250.0°C is 0.718L.

Learn more about volume at: https://brainly.com/question/24189159

#SPJ1

Answer:

D Trigonal pyramidal

Explanation went over in class:

Answer:

D. Trigonal pyramidal

Explanation:

A P E X !

Answer:

Ionic

Na has one valence electron

Chlorine has seven

Sodium loses one electron

Chlorine gains one electron

One mole of  sucrose stores 5878 KJ of energy. Then 10000J or 10 kJ is stored by 0.0017 moles or 0.58 g of sucrose.

Sucrose is a disaccharide formed from one glucose and one fructose units. Sucrose is used as the table sugar. Sucrose can store the chemical energy as well as it can release it through decomposition.

One mole of sucrose stores an energy of 5878.8 KJ.

molar mass of sucrose = 342. 3 g/mol

then, no.of moles of sucrose which stores 10 KJ energy = 10 /5878.8 = 0.0017 moles.

Mass of 0.0017 moles = no.of moles × molar mass

mass = 0.0017 × 342.3 g/mol = 0.58 g.

Therefore, 0.58 g of sucrose stores 10 J of energy.

Find more on sucrose :

https://brainly.com/question/28869238

#SPJ1

Answer:Each shell can hold a maximum number of electrons. moving through the elements in the periodic table, each atom has one more electron than the last because the number of electrons is the same as the atomic number. Electrons occupy the shells in order, starting with the shell that is nearest the nucleus.

Explanation:

Answer:

two

Explanation:

2

Answer:

two

Explanation:

nucleic acids are made up of chains of many repeating units called nucleotides. the dna molecule consists of two such chains that spiral around an imaginary axis to form a double helix (spiral.)

hope this helps :)

have a nice day !!

The value of Y in the formula when 2.8g of silicon react with 3.2g of oxygen, is 2

The numbers in the formula of a compound determine the ratio of moles of each element in the compound.

Given:

2.8g of silicon

3.2g of oxygen

[relative atomic mass of silicon is 28 and of oxygen is 16]

For silicon, n = 2.8 ÷ 28 = 0.1    (n= moles)

For oxygen, n = 3.2 ÷ 016 = 0.2

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.1 moles.

For Silicon = 0.1/0.1 = 1

For Oxygen = 0.2/0.1 = 2

Taking the mole ratio as their subscripts.

The ratio of Si:O is 1:2

SiO\(_{2}\) is the formula of silicon dioxide.

The value of y in the formula SiO\(_{Y}\) is 2 when 2.8g of silicon react with 3.2g of oxygen.

To know more about moles, click on this link

https://brainly.com/question/22540912

The final temperature of the glass and water mixture is 46.37°C.  

Temperature is a measure of the average kinetic energy of the particles and molecules that make up a substance. Temperature is often measured in degrees Celsius (°C), Fahrenheit (°F) or Kelvin (K). Temperature is a fundamental physical quantity that is used to describe the degree of hotness or coldness of a material. Temperature affects many physical and chemical properties of a substance, including its viscosity, melting point, boiling point, electrical resistance, and even its color. The speed of biological and chemical reactions is also impacted by temperature.

The total heat in the system (the glass + the water) is given by the following equation:
Heat = Mass x Specific Heat x Temperature Change
For the glass:
Heat = 41.0 g x 8.79 J/g °C x (T f - 95°C)
For the water:
Heat = 175 g x 4.18 J/g °C x (T f - 21°C)
Where T F is the final temperature.
We can set the two equations equal since the total heat in the system must be conserved:
41.0 g x 8.79 J/g °C x (T f - 95°C) = 175 g x 4.18 J/g °C x (T f - 21°C)
Solving for T f:
T f = (41.0 g x 8.79 J/g °C x (T f - 95°C)) / (175 g x 4.18 J/g° C) + 21°C
T f = (347.69 J/g °C x T f - 3451.05 J/g °C) / 719.5 J/g °C + 21°C
T f = (347.69 J/g °C x T f) / 719.5 J/g °C - 3451.05 J/g °C / 719.5 J/g °C + 21°C
T f = (347.69 T f) / 719.5 - 48.17 + 21°C
T f = (347.69 T f + 34278.85) / 719.5
T f = 46.37°C
The total heat in the system (the glass + the water) is given by the following equation:

To learn more about temperature
https://brainly.com/question/2339046
#SPJ4

Explanation:

A buffer is a solution that can resist pH change upon the addition of an acidic or basic components. It is able to neutralize small amounts of added acid or base,thus maintaining the pH of the solution relatively stable.This is important for processes and/or reactions which require specific and stable pH ranges.

I hope it's helpful!

The heat capacity of the system is -11.53 kJ/°C.

The total heat involved (qv) can be calculated by multiplying the mass of the substance with the ΔcombU value. For benzoic acid, the total heat involved is:

qv = (1.567g) × (-29.37 kJ/g) = -46.04 kJ

Similarly, for the cable, the total heat involved is:

qv = (0.0129g) × (-7.24 kJ/g) = -0.09 kJ

The total heat involved for both substances is the sum of the individual heat values:

qv = -46.04 kJ + -0.09 kJ = -46.13 kJ

To calculate the heat capacity, we use the formula qv = CΔT, where C is the heat capacity and ΔT is the temperature change. Rearranging the formula to solve for C gives:

C = qv / ΔT

Substituting the values for qv and ΔT gives:

C = (-46.13 kJ) / (4°C) = -11.53 kJ/°C

To know more about heat capacity click on below link:

https://brainly.com/question/28302909#

#SPJ11

To classify the given terms or examples with the appropriate category, follow these steps:

1. Identify the characteristics of the given term or example.
2. Determine whether the characteristics fit within the criteria for metabolic acidosis or metabolic alkalosis.

Metabolic Acidosis:
- Occurs when there is an increase in acidity within the body
- Causes can include increased production of acidic substances, reduced elimination of acids, or loss of bicarbonate
- Examples: Diabetic ketoacidosis, lactic acidosis, renal failure, severe diarrhea

Metabolic Alkalosis:
- Occurs when there is a decrease in acidity within the body
- Causes can include loss of acidic substances, increased elimination of acids, or an increase in bicarbonate
- Examples: Prolonged vomiting, excessive use of antacids, diuretic therapy, hypokalemia

After determining the characteristics of the given term or example, classify it into either metabolic acidosis or metabolic alkalosis based on its alignment with the criteria listed above.

A chemical formula is a group of chemical symbols and numbers that express the elements and the number of atoms of each element that compose a compound.

A chemical formula of a compound offers information about the proportions of each chemical element in a given chemical compound or molecule.

The chemical formula of a compound can be written by including the chemical symbols of elements, numbers as subscripts, and symbols, such as plus (+) and minus (−) signs, dashes, commas, and brackets.

A chemical formula exhibits no words but simple chemical structures can be drawn but not full structures. Chemical formulae must be limited in power rather than chemical structural formulae.

Learn more about chemical formula, here:

brainly.com/question/11140581

#SPJ1

Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula H₂. It is colorless, odorless, non-toxic, and highly combustible.Each atom of hydrogen has only one proton. Hydrogen is also the most abundant element in the universe.

The false statement is Option (d)

d) Suppose you were 60ft beneath the surface of ocean scuba diving and took a deep breath of air from your tank and held your breath. It is a good idea to start ascending without exhaling.

If you hold your breath while ascending to the surface, your lungs and the air within them expands as the water pressure weakens. since the air has no place to get out it will be pressurized between the wall of the lungs. It gets keep on swelling between the walls of the lungs .

Frequent changes in the pressure of the air which is present in the walls of the lungs during the ascending or descending without exhaling can cause a serious lung injury.

When a scuba diver descends to deeper depths in the oceans he has to breathe air through a device the compressed air consists of 71% nitrogen and 28% oxygen.

To learn more about Scuba diving:

https://brainly.com/question/1783647

#SPJ4

Answer: C

Explanation:its on unit test

Answer:

C is  the correct answer

Explanation:

Answer:

At the Earth's surface, wind blows horizontally from high pressure to low pressure areas. The speed is determined by the rate of air pressure change, or gradient, between the two pressure areas. The greater the pressure difference, the faster the winds.

- sciencing

The Four Forces That Influence Wind Speed & Wind Direction

Explanation:

The new (final) volume of the sample of gas is equal to 0.1922 \(cm^3\).

Given the following data:

To determine the new (final) volume of the sample of gas, we would apply Boyle's law:

Mathematically, Boyle's law is given by the formula;

\(PV = k\\\\P_1V_1 = P_2V_2\)

Where;

Making \(V_2\) the subject of formula, we have:

\(V_2 =\frac{P_1V_1}{P_2}\)

Substituting the given parameters into the formula, we have;

\(V_2 = \frac{47.8 \times 3}{746} \\\\V_2 = \frac{143.4}{746}\)

New volume = 0.1922 \(cm^3\)

Find more information: https://brainly.com/question/1437490

our chemistry lab. The chem 21 is a requirement for us. Basically, we were using a plate to chem lab it by one chemical to one.

Your Instructor has defined tolerances, which the Chem21 computer uses to score your response. This week's theme was about solving ten test tube mysteries. You will be informed on the website whether you are required to round your response chem lab to the correct number of Significant Figures; otherwise, you need just enter a number that lies between the correct amount minus

Here are some Chemistry Practical Class 12 experiments that will help students effectively prepare for their exams. I Making potash alum or ferrous ammonium sulphate double salt. Identifying a cation and an anion in a.

To learn more about chem lab please click on below link

https://brainly.com/question/28447712

#SPJ4