What is the pH and pOH of a solution that was made by adding 245 mL of water to 500 mL of 4 * 10 ^ - 4 M HF solution?
PH?round to 1 decimal place
pOH 1 decimal place

Answer:

paper burning is chemical property because burning is a chemical reaction.  salt being a solid is a physical property because phases of matter are physical properties of matter

Answer:

answer  in ppicture

Explanation:

The empirical formula for stannous fluoride, a substance added to toothpaste to prevent tooth decay, is SnF2, if its mass percentage composition is 24. 25% F, 75.

Sn 75.75 119/75.75m= 1\s F 24.25 19/24.25 = 2

SnF2 is the resultant compound.

Thus, the information provided is accurate.

You must first determine the mass percentage of the elements in the compound for any empirical formula problem.

Change the% to grammes after that.

Next, split each mass by its associated molar mass.

Divide all numbers by the moles response that is the least.

The chemical compound known as stannous fluoride, sometimes known as tin(II) fluoride (from the Latin stannum, "tin"), has the formula SnF2. It is a colourless solid that is utilised as a toothpaste ingredient.

To learn more about fluoride  please click on below link

https://brainly.com/question/2807538

#SPJ4

Answer:

1.02 × 10⁻³ g

Explanation:

Step 1: Given data

Number of moles of titanium (IV) oxide in 1 jelly bean (n): 1.28 × 10⁻⁵ moles

Step 2: Calculate the mass (in grams) corresponding to 1.28 × 10⁻⁵ moles of TiO₂

To convert moles to mass, we need a conversion factor. In this case, it is the molar mass of TiO₂: 79.87 g/mol.

1.28 × 10⁻⁵ mol TiO₂ × 79.87 g TiO₂/1 mol TiO₂ = 1.02 × 10⁻³ g TiO₂

In a voltaic cell, the reaction that occurs at the cathode is the reduction reaction.

A voltaic cell consists of two half-cells, each containing an electrode (cathode or anode) and an electrolyte. In the cell, electrons flow from the anode to the cathode through an external circuit, generating electricity. At the cathode, reduction takes place as the positively charged ions in the electrolyte gain electrons, leading to a decrease in their oxidation state.

A voltaic cell, often called a galvanic cell, is an electrochemical device that produces electricity through uninhibited redox processes, both oxidation and reduction. It is divided into two distinct half-cells. A half-cell is made up of an electrode (a metal strip, M) dissolved in a solution containing Mn+ ions. M can be any metal. A wire from one electrode to the other connects the two half-cells cathode and anode. The half-cells are also connected by a salt bridge.

To learn more about voltaic cell, visit:

https://brainly.com/question/26228780

#SPJ11

There are 3 elements, (option C) is the right option.

The element can be defined as one of the simplest chemical substances that cannot be decomposed in a chemical reaction and are made up of atoms all having the same number of protons.

As stated above, all elements are made up of backbone structures called atoms. The atoms of an element are the same.

According to this question, an image is given showing atoms of different colors. Each atom has the same color and belongs to the same element.

Since there are there colors, this means that there are three elements in the picture.

read more about elements

brainly.com/question/25916838

Answer:

13.1548172

Explanation:

The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles CH4, or 16.04246 gram

so 0.82 × 16.04246

Pls consider Brainliest-ing my answer! It would mean a lot! ;)

Answer:

When carbon is burned in air, it forms carbon dioxide gas and releases a large amount of heat and some light:

C+O2= CO2+ heat+ light

Answer:

When carbon is burned in air, it forms carbon dioxide gas and releases a large amount of heat and some light:

C+O2= CO2+ heat+ light

Explanation:

The chemical has a percent composition of 56.35% oxygen and 43.65% phosphorus.

A substance has an oxygen content of 88.79% and a hydrogen content of 11.19%. Calculate this compound's empirical formula. Nonetheless, it's customary to employ the atom ratio with the smallest whole number. H 2 O is the compound's empirical formula as a result.

P mass of 30.98 g and O mass of 40.00 g add up to 70.98 g.

Phosphorus: \((30.98 g / 70.98 g) x 100% = 43.65%\)

\((40 g/70.98 g) x 100% = 56.35% for oxygen.\)

To know more about phosphorus visit:-

https://brainly.com/question/4622631

#SPJ1

Answer:

C, physical change

Explanation:

take a look at the equation. Next to each form of water do you see the little (g) and (l)? These represent the state of matter the water is in. So, the water is going from a gas to a liquid. The chemical compound is the same so its a physical change, not chemical, and it is reversible. You could change the liquid water back to the gas through evaporation. Endothermic has literally nothing to do with this equation so you can easily eliminate that answer choice.

Answer:

All of them

Explanation: A molecule can be all of them

The molecular formula of the compound, given that the compound made up of N and O contains 30.4% N is N₂O₄

First, we shall obtain the molar mass of the compound. Details below:

The mole of the gas is obtained as follow:

PV = nRT

1 × 0.974 = n × 0.0821 × 273

Divide both sides by 24.0553

n = 0.974 / (0.0821 × 273)

n = 0.043 mole

Thus, the molar mass is obtained as:

Molar mass = mass / mole

Molar mass = 4 / 0.043

Molar mass = 93 g/mol

Next, we shall obtain the empirical formula of the compound. details below:

Divide by their molar mass

N = 30.4 / 14 = 2.171

O = 69.6 / 16 = 4.35

Divide by the smallest

N = 2.171 / 2.171 = 1

O = 4.35 / 2.171 = 2

Thus, the empirical formula is NO₂

Finally, we shall obtain the molecular formula of the compound. This is shown below:

Molecular formula = empirical × n = mass number

[NO₂]n = 150

[14 + (2 × 16)]n = 150

46n = 93

Divide both sides by 46

n = 93 / 46

n = 2

Molecular formula = [NO₂]n

Molecular formula = [NO₂]₂

Molecular formula = N₂O₄

Thus, the molecular formula of the compound is N₂O₄

Learn more about molecular formula:

https://brainly.com/question/29096809

#SPJ4

Answer:

Ozone layer depletion is the thinning of the ozone layer present in the upper atmosphere. This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. One chlorine can destroy 100,000 molecules of ozone. It is destroyed more quickly than it is created

Answer:

Ozone depletion, gradual thinning of Earth’s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. The thinning is most pronounced in the polar regions, especially over Antarctica. Ozone depletion is a major environmental problem because it increases the amount of ultraviolet (UV) radiation that reaches Earth’s surface, which increases the rate of skin cancer, eye cataracts, and genetic and immune system damage. The Montreal Protocol, ratified in 1987, was the first of several comprehensive international agreements enacted to halt the production and use of ozone-depleting chemicals. As a result of continued international cooperation on this issue, the ozone layer is expected to recover over time.

1890 mL of a 0.35 M NaF solution would be needed to completely react with 869 mL of a 0.38 M SrCl2 solution.

The balanced chemical equation for the reaction between sodium fluoride (NaF) and strontium chloride (SrCl2) is:

2NaF + SrCl2 → 2NaCl + SrF2

According to the equation, 2 moles of NaF are required to react with 1 mole of SrCl2.

First, we need to calculate the number of moles of SrCl2 present in 869 mL of a 0.38 M solution:

0.869 L x 0.38 mol/L = 0.33 mol SrCl2

Next, we can use the stoichiometry of the balanced equation to determine the number of moles of NaF required:

0.33 mol SrCl2 x (2 mol NaF / 1 mol SrCl2) = 0.66 mol NaF

Finally, we can calculate the volume of a 0.35 M NaF solution containing 0.66 moles of NaF:

0.66 mol NaF / 0.35 mol/L = 1.89 L or 1890 mL

Therefore, 1890 mL of a 0.35 M NaF solution would be needed to completely react with 869 mL of a 0.38 M SrCl2 solution.

To know more about stoichiometry refer here:

https://brainly.com/question/30215297

#SPJ11

A liquid

B solid

c gas

the internolecular forces in a solid state are packed and leave no spaces and in a liquid are semi packed and leave little space and in gas the particles are loose

Answer:

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

From the question

volume of substance = 250 cm³

density = 4.259 g/cm³

We have

mass = 4.259 × 250

We have the final answer as

Hope this helps you

Answer:

ionic

Explanation:

ionic transfer of e^- ions formed (charges)

ionic=non-metal+ metal

ex: F+Ca

covalent sharing e^- no true charges

covalent= non-metal+ non-metal

ex: F+P

( my notes)

Answer:

Explanation:

5. Deuterium, also known as heavy hydrogen, is a Hydrogen isotope with mass number 2.

6. Isotope is an atom of the same element with the same number of protons but different number of neutrons.

Answer:

fixed shape and a definite volume

Explanation:

Answer:

a solid has a definite shape and definte volume

Explanation:

Answer: A. H 0  μ1 = μ2 = μ3

Ha  μ1 ≠ 2μ ≠ μ3

2. Test Statistics is 95%

3. Critical F-Value is 3.76.

4. P-Value is 2.32.

5. Conclusion  Reject the null hypothesis.

6. Type of vehicle does effect the amount of green house gas emissions.

The correct order of the steps of a hypothesis test is given below.

1. Determine the null and alternative hypothesis.

2. Select a sample and compute the critical value F-test for the sample mean.

3. Determine the probability at which you will conclude that the sample outcome is very unlikely.

4. Make a decision about the unknown population.

All steps are performed in the given sequence to test a hypothesis.

The null hypothesis is rejected or accepted on the basis of level of significance. When the p-value is greater than level of significance we fail to reject the null hypothesis and null hypothesis is then accepted. It is not necessary that all null hypothesis will be rejected at 95% level of significance. To determine the criteria for accepting or rejecting a null hypothesis we should also consider p-value.

For more details on hypothesis test follow the link:

brainly.com/question/10758924

Explanation:

The Ph of a 0.15 m aqueous solution of Na Br O (the sodium salt of H Br O) is 10.7. what is the k a for H Br O is 6.0\(E^{-9}\).

An aqueous solution is a solution in which solvent is water. It is mostly shown in chemical equations by appending (a q) to relevant chemical formula. For example, solution of table salt, or sodium chloride (NaCl), in water would be represented as Na+(a q) + Cl−(a q). The word aqueous (which comes from aqua) means pertaining to, related to, similar to, or dissolved in, the water. As water is an excellent solvent and is also naturally abundant, it is ubiquitous solvent in chemistry. Since water is frequently used as solvent in experiments, the word solution refers to an aqueous solution, unless the solvent is specified.

A non-aqueous solution is a solution in which solvent is a liquid, but is not water.

Reactions in aqueous solutions are usually the metathesis reactions. Metathesis reactions are another term for the double-displacement; that is, when a cation displaces to form an ionic bond with the other anion. The cation bonded with latter anion will dissociate and bond with the other anion.

A common metathesis reaction in the aqueous solutions is a precipitation reaction. This reaction occurs when two aqueous strong electrolyte solutions mix and produce insoluble solid, also known as a precipitate. The ability of a substance to dissolve in water is determined by whether substance can match or exceed the strong attractive forces that water molecules generate between themselves. If the substance lacks the ability to dissolve in water, molecules form a precipitate.

When writing the equations of precipitation reactions, it is essential to determine precipitate. To determine the precipitate, one must consult chart of solubility. Soluble compounds are aqueous, while the insoluble compounds are the precipitate. There may not always be precipitate. Complete ionic equations and net ionic equations are used to show the dissociated ions in metathesis reactions. When performing the calculations regarding the reacting of one or more aqueous solutions, in general one must know the concentration, or molarity, of the aqueous solutions.

To know more about molarity visit: https://brainly.com/question/8732513

#SPJ4

E(r) = 8π * [(-r^3/a_0^3 + 3r^2/a_0^2 - 6r/a_0 + 6) * exp(-r/a_0)] This is the expression for the expectation value of the radial distance of the electron in the 1s state of hydrogen.

To find the expectation value of the radial distance of the electron for the 1s state of hydrogen (H), we need to calculate the integral of the radial distance multiplied by the probability density function over all space.

In the case of the 1s state of hydrogen, the radial wavefunction is given by:

R(r) = (2/a_0^3/2) * exp(-r/a_0)

Where a_0 is the Bohr radius.

To calculate the expectation value, we need to integrate the radial distance r multiplied by the square of the radial wavefunction |R(r)|^2 over all space.

E(r) = ∫ (r * |R(r)|^2) * 4πr^2 dr

Since the 1s orbital is spherically symmetric, we integrate over all space from 0 to infinity.

To simplify the calculation, we can substitute u = r/a_0:

E(u) = ∫ (u * |R(u * a_0)|^2) * 4π(a_0^3) du

Now, substituting the radial wavefunction R(u * a_0):

E(u) = ∫ (u * (2/a_0^3/2) * exp(-u)) * 4π(a_0^3) du

Simplifying further:

E(u) = 8π ∫ u^3 * exp(-u) du

This integral can be solved using integration by parts. Let's denote I(n) as the integral of u^n * exp(-u) du. We can then express I(n) in terms of I(n-1):

I(n) = -u^n * exp(-u) + n * I(n-1)

Using this relation, we can calculate E(u):

E(u) = 8π * [ -u^3 * exp(-u) + 3 * (-u^2 * exp(-u) + 2 * (-u * exp(-u) + I(0)))]

Simplifying further:

E(u) = 8π * [-u^3 * exp(-u) + 3 * (-u^2 * exp(-u) + 2 * (-u * exp(-u) + exp(-u)))]

E(u) = 8π * [(-u^3 + 3u^2 - 6u + 6) * exp(-u)]

Finally, substituting u = r/a_0 back into the equation, we obtain the expectation value of the radial distance for the 1s state of hydrogen:

E(r) = 8π * [(-r^3/a_0^3 + 3r^2/a_0^2 - 6r/a_0 + 6) * exp(-r/a_0)]

This is the expression for the expectation value of the radial distance of the electron in the 1s state of hydrogen.

To know more about  radial wavefunction,  visit:

https://brainly.com/question/30509565

#SPJ11

Answer:

a) 2, 6

a) 6

b) neutrons and protons are found in the nucleus with the electrons.

Explanation:

1.

Electronic configuration entails the arrangement of electrons within an atom. Therefore, to do this, we must know the number of electrons in the element given.

since we have been given oxygen atom, the number of electrons therein is 8.

 So;

    the electronic configuration is 2,6

2.

The atomic number of an atom is the same as the number of protons that it contains. The proton number is the number of positively charged particles in the atom of the element.

Since we have been given that the number of protons within the atom is 6, therefore, the atomic number is 6.

3.

It is false that the nucleus of an atom contains protons, neutrons and electrons. Electrons are not found in the nucleus of any atom. Only the process of electron capture during radioactivity can make this happen.

Electrons are found orbiting the atomic space in discrete energy levels.  

The p-value is greater than the significance level of 0.05, we do not reject the null hypothesis and conclude that all proportions are equal.

Firstly, let us conduct a Chi-square test of independence of categorical variables based on the information given above. We have three different cases of hypothesis testing that we have to solve one by one.

Case 1: HD​:pSun ​=rhoMan ​=pTue ​=pWed ​=pThu ​=pFri ​=pSat ​=71​
Ha​ : Not all proportions are equal.

Test Statistic
For this hypothesis, we need to compute the test statistic that is given as:
\($$\chi^2=\sum_{i=1}^{k}\frac{(O_i-E_i)^2}{E_i}$$\)  where k is the number of groups/categories. Since we have 7 days of the week, \(k = 7. $O_i$ and $E_i$\) are the observed and expected frequencies respectively.  
Here, we have equal proportions of 71 for each day of the week.
Therefore, the expected frequencies are also equal to 71.
\($$E_i = 71, i=1,2,3,4,5,6,7.$$\)

We also have to use the given information to compute the observed frequencies,
\($O_i$.$$O_1 = 90, O_2 = 99, O_3 = 122, O_4 = 123, O_5 = 130, O_6 = 160, O_7 = 126$$\)

Therefore, the test statistic can be computed as \($$\chi^2=\frac{(90-71)^2}{71} + \frac{(99-71)^2}{71} + \frac{(122-71)^2}{71} + \frac{(123-71)^2}{71} + \frac{(130-71)^2}{71} + \frac{(160-71)^2}{71} + \frac{(126-71)^2}{71}$$$$\chi^2=180.14\)

Now we have to find the p-value of this test. Since the number of degrees of freedom is k - 1 = 7 - 1 = 6, the p-value can be found using the chi-square distribution table with 6 degrees of freedom at the 0.05 significance level. The p-value is 0.000014. ConclusionSince the p-value is less than the significance level of 0.05, we reject the null hypothesis and conclude that not all proportions are equal.

The total number of accidents is \($$90+99+122+123+130+160+126=850$$\)

The percentage of accidents occurring on each day of the week can be found as follows:
\($$Sunday: $$\frac{90}{850}\times 100 = 10.59\%$$Monday: $$\frac{99}{850}\times 100 = 11.65\%$$Tuesday: $$\frac{122}{850}\times 100 = 14.35\%$$Wednesday: $$\frac{123}{850}\times 100 = 14.47\%$$Thursday: $$\frac{130}{850}\times 100 = 15.29\%$$Friday: $$\frac{160}{850}\times 100 = 18.82\%$$Saturday: $$\frac{126}{850}\times 100 = 14.82\%$$\)

From the above percentages, we can see that Friday has the highest percentage of traffic accidents.

Case 2:
HD​: Not all proportions are equal.

Ha​:pSun ​=pMon ​=pTue ​=rhoWed ​=pThu ​=rhoFri ​=rhoSat ​=71

Test Statistic

\($$E_1 = 78.57, E_2 = 86.57, E_3 = 106.86, E_4 = 107.43, E_5 = 113.57, E_6 = 139.43, E_7 = 109.14$$\)

We already know the observed frequencies,
\($$O_1 = 90, O_2 = 99, O_3 = 122, O_4 = 123, O_5 = 130, O_6 = 160, O_7 = 126.$$\)

The test statistic can be computed as:

\($$\chi^2=\frac{(90-78.57)^2}{78.57} + \frac{(99-86.57)^2}{86.57} + \frac{(122-106.86)^2}{106.86}+ \frac{(123-107.43)^2}{107.43} + \frac{(130-113.57)^2}{113.57} + \frac{(160-139.43)^2}{139.43} + \frac{(126-109.14)^2}{109.14} $$$$ \implies \chi^2=34.98$$\)
The p-value is 0.000001.
Conclusion- Since the p-value is less than the significance level of 0.05, we reject the null hypothesis and conclude that not all proportions are equal.

Case 3:

All proportions are equal.
Test Statistic
The expected frequency for each group is
\(E = \frac{850}{7} = 121.43\)
We already know the observed frequencies,
\($$O_1 = 90, O_2 = 99, O_3 = 122, O_4 = 123, O_5 = 130, O_6 = 160, O_7 = 126.$$\)

The test statistic is,

\($$\chi^2=\frac{(90-121.43)^2}{121.43} + \frac{(99-121.43)^2}{121.43} + \frac{(122-121.43)^2}{121.43} + \frac{(123-121.43)^2}{121.43} + \frac{(130-121.43)^2}{121.43} + \frac{(160-121.43)^2}{121.43} + \frac{(126-121.43)^2}{121.43}} \\\implies \chi^2=9.17$$\)

The p-value is 0.1664.

Since the p-value is greater than the significance level of 0.05, we do not reject the null hypothesis and conclude that all proportions are equal.

To know more about p-value visit:

https://brainly.com/question/30761573

#SPJ11

ANSWER

option A and B

EXPLANATION

An increase in temperature will increase the average kinetic energy of the molecule, thereby increasing the frequency of collision.

The correct answer are option A and B

Answer:

China, Mongolia, Russia, and North Korea. They were told to fly at 1400 meters but they flew at 1500 feet making them crash.

Explanation: