Solution :
[tex]pk_b = -log ( K_b)\\\\pk_b = - log ( 3.6 \times 10^{-5})\\\\pk_b = 4.44[/tex]
We know, pH of this solution :
[tex]pH = pK_a + log ( \dfrac{|conjugate\ base|}{|weak \ acid|}\\\\pH = 4.44 + log(\dfrac{0.480}{0.190})\\\\pH = 4.44 + 0.40\\\\pH =4.84[/tex]
Hence, this is the required solution.
What are the characteristics of acids and bases, and some examples of each? (20%)
Answer:
Acid :
1) they are sour in taste
2) if we put litmus paper in an acid they turn blue litmus to red and ( red litmus paper colour doesn't change )
3) acids use to react with metals
4) it releases hydrogen (H+) when dissolved in water
5) example : Hydrochloric acid , sulphuric acid , nitric acid etc..
base :
1) they are bitter in taste
2) and the red litmus paper trunes to blue and ( red litmus paper colour doesn't change )
3) it doesn't react with metals
4) it releases hydroxide (OH+) when dissolved in water
5 example : sodium hydroxide, potassium hydroxide etc...
Fill in the blank: The bonds in an ionic compound________
electrons.
Answer:
Ionic bonding is the complete transfer of valence electron
Explanation:
In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.
When CO2(g) is put in a sealed container at 730 K and a pressure of 10.0 atm and is heated to 1420 K , the pressure rises to 24.1 atm . Some of the CO2 decomposes to CO and O2.
Calculate the mole percent of CO2 that decomposes.
Express your answer using two significant figures.
Answer:
48%
Explanation:
Based on Gay-Lussac's law, the pressure is directly proportional to the temperature. To solve this question we must assume the temperature increases and all CO2 remains without reaction. The equation is:
P1T2 = P2T1
Where Pis pressure and T absolute temperature of 1, initial state and 2, final state of the gas:
P1 = 10.0atm
T2 = 1420K
P2 = ?
T1 = 730K
P2 = 10.0atm*1420K / 730K
P2 = 19.45 atm
The CO2 reacts as follows:
2CO2 → 2CO+ O2
Where 2 moles of gas react producing 3 moles of gas
Assuming the 100% of CO2 react, the pressure will be:
19.45atm * (3mol / 2mol) = 29.175atm
As the pressure rises just to 24.1atm the moles that react are:
24.1atm * (2mol / 19.45atm) = 2.48 moles of gas are present
The increase in moles is of 0.48 moles, a 100% express an increase of 1mol. The mole percent that descomposes is:
0.48mol / 1mol * 100 = 48%
an erlenmeyer flask contains 15.00mL of 0.030 M HCI before titration. 5.00 mL of 0.050 of M NaOH is added to the HCI in the flask during titration. What is the mole ratio of acid (HCI) to base (NaOH) in the balanced neutralization equation?
0.05 to 0.03
1:1
1:2
which expression. gives the actual moles of base added?
0.050x5.00
0.030x0.015
0.050x0.005
How many moles of H+ will be present following neautralization?
0.25
0.00025
0.025
Answer:
1.1
0.050*0.005
0.00025
Explanation:
Draw the most stable form of the organic products formed in the reaction of ethyl acetate and ethyl benzoate. Ethanol can be excluded from the answer.
Answer:
Please find the solution in the attached file.
Explanation:
2 HCl + Na2SO4 > 2 NaCl + H2SO4
If you start with 20 grams of hydrochloric acid, how many grams of sulfuric acid will be produced?
Answer:
15
Explanation:
Matter is never created or destroyed.
Lesson 5.04
Question 7 options:
True
False
Which type of fuel uses combustion to produce energy?
O A. Hydroelectric
B. Nuclear
O C. Biomass
D. Geothermal
Answer:
nuclear im not sure but the chances of the answer getting correct is high
structural formula for alkene with double bond st carbon 2 that shows no trans -cis isomerism C6H12
Answer:
Explanation:
Read up on this:
https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Book%3A_The_Basics_of_GOB_Chemistry_(Ball_et_al.)/13%3A_Unsaturated_and_Aromatic_Hydrocarbons/13.02%3A_Cis-Trans_Isomers_(Geometric_Isomers)
I think the answer is going to structure of 2-methyl-2-pentene.
Hello I need help please
Answer:
The concentration of an acid in a solution can be determined by making an acid-base titration. To do this, a known volume of the acid solution is gradually added alkali solution whose concentration is known, until a neutral pH is reached.
Explanation:
ou discover that the complex decomposes in water. When 0.1000 g of the complex is dissolved in water with excess NaHg(SCN)4, all of the Co(II) is precipitated as CoHg(SCN)4 (s). After the precipitate is washed and dried, its mass is found to be 0.1102 g. How many grams of cobalt are contained in the original 0.1000 grams of the complex
Answer:
6.28x10⁻³ g
Explanation:
First we convert 0.1102 grams of CoHg(SCN)₄ into moles, using its molar mass:
0.1102 g ÷ 491.9 g/mol = 2.24x10⁻⁴ mol CoHg(SCN)₄There is 1 Co mol per CoHg(SCN)₄ mol, meaning there's also 2.24x10⁻⁴ moles of Co.
We now convert 2.24x10⁻⁴ moles of Co into grams, using its molar mass:
2.24x10⁻⁴ mol Co * 28.01 g/mol = 6.28x10⁻³ gIf 50mL of 0.15M calcium sulfide is added to 30mL of 0.35M ammonium carbonate, how many grams of precipitate will form
Answer:
0.750 g
Explanation:
The reaction that takes place is:
CaS (aq) + (NH₄)₂CO₃ (aq) → CaCO₃ (s) + (NH₄)₂S (aq)First we calculate how many moles of each reactant were added, using the given volumes and concentrations:
CaS ⇒ 50 mL * 0.15 M = 7.5 mmol CaS(NH₄)₂CO₃ ⇒ 30 mL * 0.35 M = 10.5 mmol (NH₄)₂CO₃Given that they react in a 1:1 ratio, and that there are less CaS moles than (NH₄)₂CO₃ moles, CaS is the limiting reactant.
7.5 mmoles of CaS will produce 7.5 mmoles of CaCO₃.We now convert 7.5 mmol CaCO₃ into mg, using its molar mass:
7.5 mmol * 100 mg/mmol = 750 mgFinally we convert 750 mg to g:
750 mg / 1000 = 0.750 gHow many formula units are there in 14.50 moles of Ba(NO2)2?
Answer:
I am pretty sure that there is 3325.401 formula units. I might be wrong. Hope this helps!
Explanation:
it refers to the length of the entire path the object travelled
Answer:
Path length is the overall distance traveled following the path of where the object travel. ... Displacement is the distance from the starting point of the object to its final point irregardless where it travels.
iaeurphgqihrgiqerhg;iadg;iwepi
Answer:
hkdhmfewavs,nxzjrgjngrnjm
Explanation:
Answer:h hed chd dechgde chsxqwertyuioplkjhgfdsaazxcvbnm
Explanation:
Rachard is studying a sample of a substance. The sample is in a large, triangle-shaped flask. Rachard moves the sample to a small, rectangular container. Both containers are closed. Below is an image of the containers used by Rachard. She notices that the shape and the volume of the substance both change when the sample is moved. In which state of matter is the substance?
wwwwwwwwwwwwwwwwwwwwwwwweweewewwewweewweeweeweeweweweeeweew
Explanation:
Simply multiply the # of moles of O2 by a molar ratio to give the # of moles of MgO:
#moles O2 × (2 mol MgO/1 mol O2) = # moles of MgO
where the quantity inside the parenthesis is the molar ratio between MgO and O2.
How many hydrogen atoms are in 89.5 g of
C6H6 ?
Answer in units of atoms.
Solution :
Molar mass of [tex]C_6H_6[/tex] is :
M = 6×12 + 6×1 g
M = 78 g
78 gram of [tex]C_6H_6[/tex] contains [tex]6.022 \times 10^{23}[/tex] molecules.
So, 89.5 gram of [tex]C_6H_6[/tex] contains :
[tex]n = 6.022 \times 10^{23} \times \dfrac{89.5}{78}\\\\n = 6.91 \times 10^{23}[/tex]
Now, from the formula we can see that one molecule of [tex]C_6H_6[/tex] contains 2 hydrogen atom . So, number of hydrogen atom are :
[tex]h = 2\times 6.91 \times 10^{23}\\\\h = 1.38 \times 10^{22}\ atoms[/tex]
Hence, this is the required solution.
What is the pH when the hydrogen ion concentration is 1 x 10-3 M?
O a. 3.3
O b. 4
O c. 2.7
O d. 2
O e. 3
Answer:
e. 3
Explanation:
In order to solve this problem we need to keep in mind the definition of pH:
pH = -log[H⁺]As stated by the problem, the hydrogen ion concentration, [H⁺], is 1x10⁻³ M.
As all required information is available, we now can calculate the pH:
pH = -log(1x10⁻³ M)pH = 3The correct option is thus e.
An empirical formula calculation gives a molar ratio of 1.0 oxygen, 4.8 hydrogen, 4.1 carbon and 1.8 nitrogen. If the molecular mass is approximately 200 amu, what is the molecular formula
Answer:
[tex]C_8H_{10}O_2N_4[/tex]
Explanation:
Hello there!
In this case, according to the given information about the empirical formula of this compound, we can infer that these mole ratios can be rounded to the following whole numbers in order to find the empirical formula:
[tex]C_4H_5ON_2[/tex]
Whose molar mass is 97.09 amu and thus, the ratio of the molecular to the empirical molar mass is:
[tex]200/97.09=2.1[/tex]
Which is almost a factor of 2; and therefore, the resulting molecular formula is:
[tex]C_8H_{10}O_2N_4[/tex]
Regards!
If 45.6 g of Fe2O3 reacts with excess water, how much heat is required?
Explanation:
I
have not yet learnt chemistry so sorry
Answer:
350
Explanation:
Chemical Reactions:Question 3
The graph shows the energy change that occurs during a chemical reaction.
Graph 1
Energy
Reaction Progress
What conclusion can be reached based upon the graph?
Select one
The energy of the reactants is less than the energy of the products,
The energy of the products and the energy of the reactants are equal.
The energy of the products is less than the energy of the reactants
Energy was neither absorbed not released during this reaction
Answer:
because of how big it is
Explanation:
frgftvtv
The graphs shows the energy change of an exothermic reaction. Hence, the energy of products is less than the energy of reactants. Thus, option c is correct.
What is an exothermic reaction?The reaction in which heat energy is evolved to the surroundings is called an exothermic reaction. The reaction where, the heat energy is absorbed by the system is called endothermic reaction.
An energy diagram is used to describe the energy change in a reaction and the energy difference between reactants and products. In an endothermic reaction, the reactants are absorbing sufficient energy and thus easily overcome the barrier potential.
In exothermic reactions, products are absorbing energy and overcome the barrier potential. Therefore, in exothermic reactions, the potential energy of products is less than that of reactants as shown in the diagram.
Find more on energy diagram:
https://brainly.com/question/30260225
#SPJ2
A solution of carbon tetrachloride and acetic acid (CH3COOH) that is 50% carbon tetrachloride by mass is boiling at 98.6 °C. The vapor is collected and cooled until it condenses to form a new solution. Calculate the percent by mass of carbon tetrachloride in the new solution.
Answer:
The percent by mass of carbon tetrachloride in the new solution is 72.6
Explanation:
Molecular weight of Carbon Tetrachloride is 154 g/mol
Molecular weight of CH3COOH is 60g/mol
Mass fraction of CCl4 is 0.5
Mass fraction of CCl4 is (0.5/154)/{(0.5/154) + (0.5/60)}
Mass fraction of CCl4 is X = 0.2803 and Y = 1-X
As per Raoul’s law
Y Pt = X * P1
Pt = X * P1 + YP2
Pt = 0.2803 * 1377 + (1-0.2803) * 519
Pt = 759.557 torr
Substituting the given values we get
Y1 = X1P1/Pt
Y1 = 0.2803 * 1377/759.557
Y1 = 0.508
Mass fraction
(0.508)(154)/{( (0.508)(154)) + (1-0.508)(60)}
= 0.726 = 72.6 %
The density of a 25.0% HCl solution (by mass) is 1.05 g/mL, what is the molality of the solution?
(MW HCI: 36.46g/mol, H2O: 18.015g/mol)
a. 9.60 m
b. 6.86 m
c. 7.20 m
d. 9.14 m
e. None of the above
Answer:
[HCl] = 14.7M in HCl
Explanation:
Definition of Molarity (M) = moles solute / Liters of Solution
Given 25.0% HCl (aq) => 25g HCl/100g Solution => ? moles HCl/Liter Solution
Convert 25g HCl to moles = moles solute
moles HCl => moles HCl = 25g HCl / 18.015g HCl/mole HCl = 1.387732 mole HCl = 1.4 moles HCl (2sig.figs.)
Determine Liters of Solution as follows:
Given 25% HCl Solution => 25g HCl/100 g Solution
100 g Solution = (100 g solution) / (1.05 g Solution/ml Solution )
= 95.2381 ml Solution x 1 Liter Solution/1000 ml Solution
= 0.0952 Liters Solution
Apply above mole and volume data to definition of mole.
∴Molarity = moles solute / Liters solution
= 1.4 moles solute (HCl)/0.0952 L solution
= 14.7 Molar in HCl(aq)
A mixture of 14.0 grams of H2, 84.0 grams of N2, and 64.0 grams of O2 are placed in a flask. The partial pressure of the O2 is 78.00 torr. What is the total pressure in the flask
Answer:
[tex]P_{tot}=465.27torr[/tex]
Explanation:
Hello there!
In this case, according to the given information, it will be possible for us to use the Dalton's law, in order to solve this problem. However, we first need to calculate the mole fraction of oxygen by firstly calculating the moles of each gas:
[tex]n_{H_2}=\frac{14.0g}{2.02g/mol} =6.93mol\\\\n_{N_2}=\frac{84.0g}{28.02g/mol}=3.00mol\\\\n_{O_2}=\frac{64.0}{16.00g/mol} =2.00mol[/tex]
Next, we calculate such mole fraction as follows:
[tex]x_{O_2}=\frac{2}{6.93+3+2} =0.168[/tex]
Then, given the following equation:
[tex]P_{O_2}=P_{tot}*x_{O_2}[/tex]
So we solve for the total pressure as follows:
[tex]P_{tot}=\frac{P_{O_2}}{x_{O_2}} \\\\P_{tot}=\frac{78.00torr}{0.168} \\\\P_{tot}=465.27torr[/tex]
Regards!
A radioactive nuclide is used to detect eye tumors. An atom of this radionuclide contains 15 protons, 15 electrons, and
17 neutrons. Which is symbol of this radionuclide?
Answer: ³²P
Explanation:
The radionuclide in question is known as Phosphorus-32. It is an isotope of Phosphorus that is radioactive and has one more neutron than the normal phosphorus does.
Phosphorus does not exist in nature and is created artificially by bombarding the normal stable phosphorus with neutrons. Due to its radioactive nature, it has proven to be useful in the medical industry where it has been used to detect eye tumors as well as in treating some diseases.
A chemistry student needs 90.00 g of thiophene for an experiment. She has available 0.50 kg of a 12.3% w/w solution of thiophene in ethanol.
Calculate the mass of solution the student should use. If there's not enough solution, press the 'No solution" button
Round your answer to 3 significant digits. Put the answer in terms of the amount of grams.
Answer: The correct answer is No solution.
Explanation:
We are given:
Given mass of thiophene for the experiment = 90.00 g
12.3% w/w solution of thiophene
This means that 12.3 g of thiophene is present in 100 g of solution
Applying unitary method:
If 12.3 g of thiophene is present in 100 g of solution
So, 90.00 g of thiophene will be present in [tex]\frac{100g}{12.3g}\times 90.00g=731.7g [/tex] of solution
Converting it into kilograms:
1 kg = 1000 g
So, 731.7 g = 0.7317 kg
As the given amount of solution is 0.50 kg which is less than the required amount.
Thus, there is not enough solution the student should use.
The diameter of a circle is 17 cm. Find its circumference in terms of \piπ.
Answer: sorry I didnt know the answer it wont let me get off
Explanation:
Will Mark Brainliest.
1. Analysis of a hydrate of iron(III) chloride revealed that in a 10.00g sample of hydrate, 6.00 g is anhydrous iron(III) chloride and 4.00 g is water. Determine the formula and the name of the hydrate.
Answer:
FeCl₃ . 6H₂O, BRAINLIST PLZ
Explanation:
1) The chemical formula of iron(III) chloride is FeCl₃ (the oxidation number of Fe is 3+, and the oxidation number of Cl is 1-).
2) The formula that you are lookin for the hydrate is of the type FeCl₃ . n H₂O, where n is the number of water molecules per each unit formula of Fe₂O₃.
3) Find the mass of anhydrous FeCl₃ by difference:
mass of FeCl₃ = mass of the sample - mass of the water in the sample
mass of FeCl₃ = 5.49g - 2.20 g = 3.29 g
4) Convert the mass of FeCl₃ in number of moles
number of moles = mass in grams / molar mass
molar mass of FeCl₃ = 55.845 g/mol + 3×35.453 g/mol = 162.204 g/mol
number of moles = 3.29 g / 162.204 g/mol = 0.0203 mol FeCl₃
5) Convert the mass of water in number of moles:
molar mass of water = 18.015 g/mol
number of moles of water = mass in grams / molar mass = 2.20 g / 18.015 g/mol = 0.122 moles H₂O
6) Find the mole ratio of water to iron chloride:
0.122 mol water / 0.0203 mol iron chloride = 6.01 ≈ 6
Therefore, the complete formula of the hydrate is FeCl₃ . 6H₂O,
Please help and explain how to do it need the answer asap, please.
Answer:
45 and 20 c2 Or4
Explanation: