ection
9)
A compound consists of 25.9% nitrogen and 74.1% oxygen by mass. What is the empirical
formula of the compound?
A)
NOZ
B)
NO
C)
N₂Os
D)
0
1
N20
2
3
4
5
6
7
8
9
0
21
2

Answer:

[tex]Ka=3.98x10^{-4}[/tex]

Explanation:

Hello there!

In this case, since the modelling of titration problems can be approached via the Henderson-Hasselbach equation to set up a relationship between pH, pKa and the concentration of the acid and its conjugate base, we can write:

[tex]pH=pKa+log(\frac{[NO_2^-]}{[HNO_2]} )[/tex]

Whereas the pH is given as 3.14 and the concentrations are the same, that is why the pH would be equal to the pKa as the logarithm gets 0 (log(1)=0); thus, we can calculate the Ka via:

[tex]Ka=10^{-pKa}=10^{-3.14}\\\\Ka=3.98x10^{-4}[/tex]

Best regards!

Answer:

copper hiiiiiiiiiiiii

Answer:

The changes of state occur during distillation are boiling followed by condensation. The liquid is converted into its vapor phase at its boiling point and the vapor is then condensed back to liquid on cooling.

Explanation:

Heart me pls

Answer: The volume of nitrogen gas that is required is 13944 L.

Explanation:

Given values:

Number of molecules of ammonia gas = [tex]7.5\times 10^{26}[/tex]

According to the mole concept:

[tex]6.022\times 10^{23}[/tex] number of molecules are present in 1 mole of a compound

So, [tex]7.5\times 10^{26}[/tex] number of molecules will be present in [tex]\frac{1}{6.022\times 10^{23}}\times 7.5\times 10^{26}=1.245\times 10^3 moles[/tex] of ammonia gas

The chemical equation for the formation of ammonia gas follows:

[tex]N_2 (g) + 3H_2(g) \rightarrow 2NH_3(g)[/tex]

According to the stoichiometry of the reaction:

2 moles of ammonia gas are produced from 1 mole of nitrogen gas

So, [tex]1.245\times 10^3[/tex] moles of ammonia gas will be produced from [tex]\frac{1}{2}\times 1.245 \times 10^3=6.225\times 10^2[/tex] moles of nitrogen gas

At STP conditions:

1 mole of a gas occupies 22.4 L of volume

So, [tex]6.225 \times 10^2[/tex] moles of nitrogen gas will occupy [tex]\frac{22.4 L}{1 mol}\times 6.225\times 10^2 moles=13944 L[/tex] of volume

Hence, the volume of nitrogen gas that is required is 13944 L.

Answer:

13

Explanation:

0.711 moles C

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[Given] 4.28 × 10²³ atoms C

[Solve] moles C

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

0.710727 moles C ≈ 0.711 moles C

Answer:

Benedict's test would determine if the sample is a reducing sugar, and Barfoed's test would determine if it is a monosaccharide or disaccharide.

Answer:

Exercise 1

a)  140 m

b)  100 m

c)  180 m

d) 140 m

Exercise 2

a) 20 yards

b) 30 yards

c) 20 yards

d) 55 yards

Exercise 3

a)  11 Kilometers

b) 7 Kilometers

Explanation:

Exercise 1

Distance from B to C = 140 m

Distance from  to D = 100 m

Total distance = 100+40+40 = 180 m

Total displacement i.e. distance between A and D is 140 m

Exercise 2

a) Distance from B to C = 35 -15 = 20 yards

b) Distance from C to D  = 5 + 35  = 30 yards

c) Distance from B to D = 5 + 15 = 20 yards

d) Displacement = 5 + 50 = 55 yards

Exercise 3

a) The total distance travelled = 5 + 2 + 4 = 11 Kilometers

b) Displacement = 5-2 + 4 = 7 Kilometers

Answer:

pH = 5.35

Explanation:

Given 1.60 grams sodium acetate (NaOAc(aq))*** added to 50ml of 0.10M acetic acid (HOAc(aq)) solution.

Applying common ion effect keeping in mind that the addition of NaOAc provides the common-ion (OAc⁻).

      HOAc(aq) ⇄          H⁺(aq)            +                 OAc⁻(aq)

 I      0.10m          1.32 x 10⁻³M ≈ ∅M*     (1.6g/82.03g/mol) / 0.050L = 0.39M

 C       -x                         +x                                0.39M + x ≈ 0.39M**

 E    0.10M - x                  x                                    0.39M

       ≈ 0.10M

Ka = [H⁺][OAC⁻]/[HOAC] => [H⁺] = Ka·[HOAc] / [OAc⁻]

[H⁺] = (1.75 X 10⁻⁵)(0.10) / (0.39) = 4.5 x 10⁻⁶M

∴ pH = -log[H⁺] = -log(4.5 x 10⁻⁶) = -(-5.35) = 5.35

_______________________________________________

* [H⁺] before adding NaOAc = SqrRt(Ka · [HOAc]) = SqrRt(1.75 x 10⁻⁵· 0.10) = 1.32 x 10⁻³M. Since this concentration value is so small, the initial [H⁺] is assumed to be zero molar (∅M).

** The added [H⁺] is negligible and dropped in the ICE table. That is, adding ~[H⁺] in the order of 10⁻³M does not change the H⁺ ion concentration sufficiently to affect problem outcome and is therefore dropped in the ICE table.

*** Acetic Acid and Sodium Acetate are frequently written HOAc and NaOAc where the OAc⁻ anion is the acetate ion (CH₃COO⁻) for brevity.

The pH of the solution measures the acid of the liquid throughout the molar concentration of hydrogen ions in a solution.

[tex]\bold{CH_3COONa \ mass = 1.60\ g}\\\\[/tex]

Solution Volume (V) [tex]=50.0\ mL =0.05\ L\\\\[/tex]

[tex]\bold{CH3COONa \ molarity =0.10\ M }[/tex]

[tex]\bold{\text{Calculating the CH3COONa moles} =\frac{mass}{molar\ mass}}[/tex]

                                                       [tex]= \frac{1.60\ g}{82.03\frac{g}{mol}} \\\\=0.0195\ mol\\\\[/tex]

[tex]\bold{M = \frac{ \text{amount of solute moles} } { \text{solution volume in L} }}[/tex]

     [tex]= \frac{0.0195\ mol}{0.05\ L}\\\\ =0.39\ M[/tex]

Using Henderson Hasselbach equation:

[tex]\bold{pH = -\log K_{a} + \log{[salt]}{[acid]}}\\\\[/tex]

     [tex]=\bold{ -\log (1.75\times 10^{-5}) + \log ( \frac{0.39}{0.10}) }\\\\=\bold{ 4.757 + \log (3.9)}\\\\=\bold{ 4.757 + 0.5910}\\\\=\bold{ 5.348}\\\\=\bold{ 5.35}\\[/tex]

So, the final answer is "5.35".

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Answer: B) calories

Explanation:

The 4-4-9 system is used to estimate the number of calories in food. Under this system, it is assumed that one gram of Protein, one gram of Carbohydrates and one gram of Fats each contribute 4, 4 and 9 calories respectively to the caloric total.

This means that to find out the number of calories in food, multiply the total grams of proteins by 4, the total grams of carbohydrates by 4 and the total grams of Fats by 9 and then add up the results to find out the caloric contribution of Protein, Carbohydrates and Fats.  

Answer:

It's not C calories i put that and missed it

Explanation:

Element X Exists as diatomic molecules . In which group of the Periodic Table is X placed ?

Group VII

Group VII - elements are Fluorine , Chlorine , Bromine and Iodine .

They exist in diatomic molecules as F2 , Cl2 , Br2 and I2 .

Answer:

Following are the solution to these question:

Explanation:

Simple diffusion implies which molecules can move across a cell membrane instead of using the incorporated protein structure channels. Its flow of molecules across these canals is enabled by diffusion. It has steroid hormones and N2.

Facilitated diffusion of molecules via cell membranes, or active transportation, which would be the random mass transit process of molecules or ions via unique cellular membranes from the transmembrane. It has K+ and Glucose.

This is an electrophilic addition of a hydrogen halide to an alkene.

The pi bond is attacked by the electrophilic H⁺ from the H⁺Cl⁻, resulting in the loss of the double bond and the formation of a tertiary carbocation on C2. A less stable carbocation intermediate with the positive charge on C3 is also formed.

The nucleophilic Cl⁻ then attacks the carbocations, forming the haloalkane products. The major product will be 2-chloro-2-methybutane, where the Cl is bonded to the most substituted C (Markovnikov's rule). The minor product, if you have to worry about it, will be 2-chloro-3-methylbutane. The major product has no stereoisomers to worry about as it's achiral.

The attached image shows the scheme of this reaction. Only the major product is shown.  

The thermometers with red liquid usually depicts a kerosene based column with red dye. It is more safe than mercury thermometer. The red liquid inside the thermometer moves up due to the molecules of the liquid move faster and get a little further apart. The correct option is B.

The device which is used to measure the temperature is defined as the thermometer. It can measure the temperature of a solid such as food, a liquid like water and a gas like air.

The thermometers which are developed for clinical purposes are called clinical thermometers. It can also measure the temperature of human body. It is a long narrow glass tube which contain a bulb and consists of mercury at the end.

When a thermometer is heated, the molecules present in the liquid inside the thermometer get a little further apart. Because the liquid takes up more space. So the red line moves up in the tube.

Thus the correct option is B.

To know more about thermometer, visit;

https://brainly.com/question/28034450

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Answer:

c ammonium hydroxide nh4oh has higher ph value and its a base

plz mark me branliest

Answer:

c) ammonium hydroxide

Explanation:

ammonium hydroxide nh4oh has higher ph value, and it is an alkaline

Answer:

eliptical

Explanation:

Answer:

False

Explanation:

Lead sulfate is insoluble in water and sinks in water

(sorry if it's wrong)

Answer:

the population of grasshoppers would rise since there is less owls to eat them.

Explanation:

hope this helps

Answer:

The percentage composition of a compound expresses how much of each element is in the compound.

Answer: [tex]\Delta G[/tex] for the reaction   is -90kJ

Explanation:

The balanced chemical reaction is,

[tex]2H_2S(g)+SO_2(g)\rightarrow 3S_{rhombic}(s)+2H_2O(g)[/tex]

The expression for Gibbs free energy change is,

[tex]\Delta G=[n\times G_{products}]-[n\times G_{reactants}][/tex]

Putting the values we get :

[tex]\Delta G=[3\times G_f{S,rhombic}+2\times G_f{H_2O}]-[2\times G_f{H_2S}+1\times G_f{SO_2}][/tex]

[tex]\Delta G=[(3\times 0kJ/mol)+(2\times -229kJ/mol)]-[(2\times -34kJ/mol) +(1\times -300kJ/mol)][/tex]

[tex]\Delta G=-90kJ[/tex]

Thus [tex]\Delta G[/tex] for the reaction[tex]2H_2S(g)+SO_2(g)\rightarrow 3S_{rhombic}(s)+2H_2O(g)[/tex]   is -90kJ

Answer:

To explain what caused this mass extinction, scientists have focused on events that would have altered our planet's climate in dramatic, powerful ways. The leading theory is that a huge asteroid or comet slammed into Earth 65 million years ago, blocking sunlight, changing the climate and setting off global wildfires.

Answer:

A.

Explanation:

zinc and hydrochloric acid reacts to form zinc chloride and hydrogen.

hope it helps. :)

Answer:  4.22 grams of solute is there in 278 ml of 0.038 M [tex]Fe_2(SO_4)_3[/tex]

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

[tex]Molarity=\frac{n}{V_s}[/tex]

where,

n = moles of solute

[tex]V_s[/tex] = volume of solution in L

Now put all the given values in the formula of molality, we get

[tex]0.038M=\frac{n}{0.278L}[/tex]

[tex]n=0.0105mol[/tex]  

mass of  [tex]Fe_2(SO_4)_3[/tex] = [tex]moles\times {\text {Molar Mass}}=0.0105\times 399.88g/mol=4.22g[/tex]

Thus 4.22 grams of solute is there in 278 ml of 0.038 M [tex]Fe_2(SO_4)_3[/tex]

Answer:

2-to produce copies of a DNA molecule

Answer:

Hypoflorous acid, HOF

Explanation:

From the question, we're told that the helium atoms effuses 3 times than the said gas X.

We can determine the rate of effusion by using the formula

r is inversely proportional to 1/√M, where M is the molecular mass of the gas.

And also,

r is inversely proportional to 1/t, where t is the time taken for effusion.

From both formulas I listed, we can conclude that t is directly proportional to √M. And thus we proceed.

The molecular mass of Helium is 4.

tHe = tX/3, where tx is the time taken for the unknown gas X

As of yet, we don't know the molecular mass of X. Next, we say that

tX/tHe =√Mx/MHe

3 = √Mx/4

If we square both the sides, to remove the square root, we have

9 = Mx/4

Mx = 36

The molecular mass of the unknown gas X is 36.

Answer:

use the formula pressure 1 ÷ temperature 1 = pressure 2 ÷ temp 2

so your equation would look like this,

p2= p1(T2)÷ T1

so p2 =5.5(18)÷23

so it would be 4.304347826

round as you must