Answer:
yee I'm excellent in maths and science
Calculate the pH of a solution containing 25 g of barium hydroxide (171.34 mel) dissolved in 250 mL of
solution.
Answer:
14
Explanation:
Step 1: Calculate the moles corresponding to 25 g of Ba(OH)₂
The molar mass of Ba(OH)₂ is 171.34 g/mol.
25 g × 1 mol/171.34 g = 0.15 mol
Step 2: Calculate the molar concentration of Ba(OH)₂
Molarity is equal to the moles of solute divided by the liters of solution.
[Ba(OH)₂] = 0.15 mol/0.250 L = 0.60 M
Step 3: Calculate the molar concentration of OH⁻
Ba(OH)₂ is a strong base according to the following equation.
Ba(OH)₂ ⇒ Ba²⁺ + 2 OH⁻
The molar ratio of Ba(OH)₂ to OH⁻ is 1:2. The molar concentration of OH⁻ is 2/1 × 0.60 M = 1.2 M.
Step 4: Calculate the concentration of H⁺
We will use the ionic product of water expression.
Kw = 1.0 × 10⁻¹⁴ = [H⁺] × [OH⁻]
[H⁺] = 1.0 × 10⁻¹⁴/[OH⁻] = 1.0 × 10⁻¹⁴/1.2 = 8.3 × 10⁻¹⁵ M
Step 5: Calculate the pH of the solution
We will use the definition of pH.
pH = -log [H⁺] = -log 8.3 × 10⁻¹⁵ = 14
What is 0.738 × 104? Enter your answer in the box.
_____
A lab requires 3.50L of a 2.0M solution of HCl. What volume of a 6.0M solution is needed to make this solution?
Answer:
THE ANSWER IS 1.167L
Explanation:
Answer correctly please
Answer:
C.
Explanation:
How many moles of aluminum oxide will be produced from 0.50 mol of oxygen?
4 Al + 3 O2→ 2 Al2O3
Answer:
[tex]\boxed {\boxed {\sf \frac {1}{3} \ mol \ Al_2O_3 \approx 0.34 \ mol \ Al_2O_3}}[/tex]
Explanation:
We will use stoichiometry to solve this problem. The reaction given has a formula of
[tex]4Al+3O_2 \rightarrow 2Al_2O_3[/tex]
The coefficients tell us the number of moles necessary for the reaction.
The reaction requires 3 moles of oxygen to produce 2 moles of aluminum oxide. We can make a ratio.
[tex]\frac {3 \ mol \ O_2}{ 2\ mol \ Al_2O_3}}[/tex]
Since we are doing the reaction with 0.5 moles of oxygen, we multiply the ratio by that number.
[tex]0.5 \ mol \ O_2 *\frac {3 \ mol \ O_2}{ 2 \ mol \ Al_2O_3}}[/tex]
Flip the ratio so the moles of oxygen cancel each other out.
[tex]0.5 \ mol \ O_2 *\frac {2 \ mol \ Al_2O_3}{ 3 \ mol \ O_2}}[/tex]
[tex]0.5 *\frac {2 \ mol \ Al_2O_3}{ 3 }[/tex]
[tex]\frac {1 \ mol \ Al_2O_3}{ 3 }[/tex]
[tex]\frac {1}{3} \ mol \ Al_2O_3 = 0.33333 \ mol \ Al_2O_3 \approx 0.34 \ mol \ Al_2O_3[/tex]
0.5 moles of oxygen produces 1/3 or approximately 0.34 moles of aluminum oxide.
When putting hydrogen peroxide on an open wound, the wound begins to bubble and foam. Has a chemical reaction occurred? Explain your answer.
Answer:
Bubbling can indicate a chemical reaction
Explanation:
Chemical reaction takes place with the beginning of bubbles and foam when hydrogen peroxide is put onto an open wound. This compound does not only heal the wound but also damages the body as it also kills the nearby healthy cells.
What is a chemical reaction?
Chemical reaction is a process which leads to chemical transformation of a chemical substance into another.
Hydrogen peroxide bubbles when it comes into contact with an enzyme called catalase. Most of the cells in the body contain catalase enzyme, so whenever the tissue is damaged, the enzyme catalase is released from the cell and it becomes available to react with the peroxide ion.
Hydrogen peroxide applied on a cut produces a white, fizzling foam which is actually a sign that the solution is killing the bacteria as well as the healthy cells around it.
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what do protons determine about an element
Answer:
The number of protons in one atom of an element determines the atom's identity, and the number of electrons determines its electrical charge. The atomic number tells you the number of protons in one atom of an element. It also tells you the number of electrons in a neutral atom of that element.
Explanation:
Ca and F what are the name of the ionic compounds
Answer:
Calcium flouride?
Explanation:
Quite self explanatory
Which organism dna will differ the most from the leopard
Answer:
Lancelet
Explanation:
This is because a Lancelet is a small elongated marine invertebrate that lacks all of the physiological and biological traits of a leopard
To what temperature must a balloon, initially at 25°C and 2.00 L, be heated in order to have a volume of 6.00 L
Answer:
894 deg K
Explanation:
The computation is shown below:
Given that
V1 denotes the initial volume of gas = 2.00 L
T1 denotes the initial temperature of gas = 25 + 273 = 298 K
V2 denotes the final volume of gas = 6.00 L
T2 = ?
Based on the above information
Here we assume that the pressure is remain constant,
So,
V1 ÷ T1 = V2 ÷ T2
T2 = T1 × V2 ÷ V1
= (298)(6) ÷ (2)
= 894 deg K
3. You will need to make ~0.1 M solutions of one (or more) of the following salts. For each compound, determine (or look up) its molecular weight, and determine the mass necessary to make 100.0 mL of 0.100 M solution. Pay attention to significant figures! Sodium acetate anhydrous Sodium acetate trihydrate Iron(III) chloride hexahydrate g
Answer: The mass of sodium acetate anhydrous required is 0.820 g
The mass of sodium acetate trihydrate required is 1.36 g
The mass of Iron (III) chloride required is 2.70 g
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n = moles of solute
= volume of solution in ml
1. moles of =
Now put all the given values in the formula of molarity, we get
[tex]0.100=\frac{x\times 1000}{82.03\times 100.0}[/tex]
[tex]x=0.820g[/tex]
Therefore, the mass of sodium acetate anhydrous required is 0.820 g
2. moles of [tex]CH_3COONa.3H_2O[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{xg}{136.08g/mol}[/tex]
Now put all the given values in the formula of molarity, we get
[tex]0.100=\frac{x\times 1000}{136.08\times 100.0}[/tex]
[tex]x=1.36[/tex]
Therefore, the mass of sodium acetate trihydrate required is 1.36 g
3. moles of [tex]FeCl_3.6H_2O[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{xg}{g/mol}[/tex]
Now put all the given values in the formula of molarity, we get
[tex]0.100=\frac{x\times 1000}{270.33\times 100.0}[/tex]
[tex]x=2.70g[/tex]
Therefore, the mass of Iron (III) chloride required is 2.70 g
.....plllzzz heeelp me fast??
Answer:
Explanation:
It is 11
Calcium sulfate is ionic or covalent bond
Answer:
The Lewis structure for the sulfate ion consists of a central sulfur atom with four single bonds to oxygen atoms. This yields the expected total of 32 electrons. Since the sulfur atom started with six valence electrons, two of the S-O bonds are coordinate covalent.
Explanation:
Then that means it has both.
_____________refers to the soil that is frozen solid all year round, and does not even melt in the summer.
Use this website to answer the question: https://thewildclassroom.com/biomes/artictundra-2/
Question 5 options:
verglas
glaze
permafrost
frost
Answer:
Permafrost is any part of the ground that remains completely frozen or colder
This subject is science.
All the members of one community living in a particular area make up a population. True or False.
Please help please please please.
Answer:
false
Explanation:
All the members of one species in a particular area are referred to as a population. All the different populations that live together in an area make up a community. The community of organisms that live in a particular area, along with their nonliving surroundings, make up an ecosystem.
Plz help me I am!!!!
Oxalic Acid, a compound found in plants and vegetables such as rhubarb, has a mass percent composition of 26.7% C, 2.24% H, and 71.1% O. Oxalic acid can interfere with respiration and cause kidney or bladder stones. If a large quantity of rhubarb leaves is ingested, the oxalic acid can be toxic. The lethal dose (LD50) in rats for oxalic acid is 375 mg/kg. Rhubarb leaves contain about 0.5% by mass of oxalic acid. (Show your work, using the insert equation tool :) What is the empirical formula of oxalic acid
Answer:
HCO₂
Explanation:
From the information given:
The mass of the elements are:
Carbon C = 26.7 g; Hydrogen H = 2.24 g Oxygen O = 71.1 g
To determine the empirical formula;
First thing is to find the numbers of moles of each atom.
For Carbon:
[tex]=26.7 \ g\times \dfrac{1 \ mol }{12.01 \ g} \\ \\ =2.22 \ mol \ of \ Carbon[/tex]
For Hydrogen:
[tex]=2.24 \ g\times \dfrac{1 \ mol }{1.008 \ g} \\ \\ =2.22 \ mol \ of \ Hydrogen[/tex]
For Oxygen:
[tex]=71.1 \ g\times \dfrac{1 \ mol }{1.008 \ g} \\ \\ =4.44 \ mol \ of \ oxygen[/tex]
Now; we use the smallest no of moles to divide the respective moles from above.
For carbon:
[tex]\dfrac{2.22 \ mol \ of \ carbon}{2.22} =1 \ mol \ of \ carbon[/tex]
For Hydrogen:
[tex]\dfrac{2.22 \ mol \ of \ carbon}{2.22} =1 \ mol \ of \ hydrogen[/tex]
For Oxygen:
[tex]\dfrac{4.44 \ mol \ of \ Oxygen}{2.22} =2 \ mol \ of \ oxygen[/tex]
Thus, the empirical formula is HCO₂
What attractive force pulls electrons toward protons to form chemical bonds?
A. Chemical bonding
B. Attraction of opposites
C. Electronegativity
D. Ionization energy
Answer:
C). Electronegativity.
Explanation:
'Electronegativity' is described as the tendency or a measure of the ability of an atom or molecule to attract electrons that leads to the formation of chemical bonds. It is denoted by 'χ', a Greek letter. The elements like Fluorine having a very high rate of electronegativity, its atom would attract the electrons more strongly while the elements with lesser electronegativity like Cesium would possess a lesser tendency to attract electrons towards it in order to form a bond. Thus, option C is the correct answer.
Explain the term mole ratio in your own words When would you use this term ?
Answer:
A mole ratio is the ratio between the amounts in moles of any two compounds involved in a chemical reaction.
Mole ratios are used as conversion factors between products and reactants in many chemistry problems.
Explanation:
Water is amphoteric. If it reacts with a compound that is a stronger acid than itself, water acts as a
Answer:
Water acts as a base in the presence of a strong acid
Explanation:
Water,being an amphoteric compound, can act both as an acid and as a base.
In the presence of an acid , water acts as a base but in the presence of a base, water acts as an acid.
What is the precipitation like in the arctic tundra?
Use this website to answer the question: https://thewildclassroom.com/biomes/artictundra-2/
Question 4 options:
In summer, it typically rains less than 5 cm (<2 inches), while in winter it rains 25–44 cm (10–17 inches).
There is an average of 20 – 35 inches of rainfall a year.
The range is from 15-25cm (6-10 inches) a year where most falls as snow.
It can can also be called a cold desert due to its lack of precipitation.
Answer:
In summer, it typically rains less than 5 cm (<2 inches), while in winter it rains 25–44 cm (10–17 inches).
Explanation:
because tundra vegetation is mostly found in desert areas
A dilute solution of hydrofluoric acid has a volume of 3.0 L and a molarity of 3.0
M. If the original solution had a volume of 2.0L, what was the initial molarity?
Answer:
4.5M
Explanation:
The solution was diluted from 2.0L to 3.0L, the dilution factor was:
3.0L / 2.0L = 1.5.
That means the solution was diluted 1.5 times.
As the final molarity of the diluted solution is 3.0M, the initial molarity of the solution was:
3.0M * 1.5 =
4.5M is the molarity of the original solution29. Which is the electron configuration of an atom
in the excited state?
(1) 1s 2s²2p2
(2) 1s 2s22p'
(3) 1s 2s22p5352
(4) 1s²2s²2p%35'
Reactants for a certain reaction are combined in a solution. Which solution
would have the most successful collisions and so enable the reaction to
proceed quickly?
A. A solution at low concentration and low temperature
B. A solution at high concentration and low temperature
O C. A solution at high concentration and high temperature
D. A solution at low concentration and high temperature
The correct answer is solution B!
PLEASE HELP!
A piece of metal is heated to a temperature of 50.0°C and then placed in a calorimeter containing 50.0 g of water at 27.0°C. The water temperature increases to 35.0°C. How many joules of heat were transferred from the metal to the water? (Cwater = 4.18J/g•°C)
Answer: 1672 Joules
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.
[tex]Q=m\times c\times \Delta T[/tex]
Q = Heat absorbed by water = ?
c = heat capacity of water = [tex]4.18 J/g^0C[/tex]
Initial temperature of the water = [tex]T_i[/tex] = [tex]27^0C[/tex]
Final temperature of the water = [tex]T_f[/tex] = [tex]35^0C[/tex]
Change in temperature ,[tex]\Delta T=T_f-T_i=(35.0-27.0)^0C=8.0^0C[/tex]
Putting in the values, we get:
[tex]Q=50.0g\times 4.18J/g^0C\times 8.0^0C=1672J[/tex]
As heat absorbed by water is equal to the heat released by metal, the Joules of heat transferred are 1672 Joules
Consider the reaction of tin with potassium hydroxide and water. Sn (s) 2KOH (aq) 4H2O (l) K2Sn(OH)6 (s) 2H2 (g) Determine the limiting reactant in a mixture containing 122 g of Sn, 134 g of KOH, and 63.9 g of H2O. Calculate the maximum mass (in grams) of potassium hydroxystannate, K2Sn(OH)6, that can be produced in the reaction. The limiting reactant is:
Answer:
The limiting reactant is: H₂O
265.3 g of K₂Sn(OH)₆ are formed in the reaction.
Explanation:
The reaction is:
Sn(s) + 2KOH (aq) + 4H₂O(l) → K₂Sn(OH)₆ (s) + 2H₂ (g)
The first step to solve is to determine the moles of each reactant:
We controlled that reaction is ballanced.
122 g . 1mol / 118.71g = 1.03 moles of Sn
134g . 1mol /56.1g = 2.39 moles of KOH
63.9 g .1mol /18g = 3.55 mol of water
Stoichiometry is 1:2:4.
Sn is the lowest reactant and water, the highest, but I can see, that water is the limiting.
1 mol of Sn needs 4 moles of H₂O to react
Then, 1.03 moles of Sn may react to (1.03 . 4)/1 = 4.12 moles.
We only have 3.55 moles. It's ok.
2 moles of KOH need 4 moles of H₂O to react
Then, 2.39 moles of KOH may react to (2.39 . 4) /2 = 4.78 moles.
We only have 3.55, there's no enough water.
So 4 moles of water can produce 1 mol of potassium hydroxystannate
Then, 3.55 moles of H₂O may produce (3.55 . 1)/4 = 0.8875 moles.
We convert moles to mass: 0.08875 mol . 298.91g /1mol =265.3g
What volume, in milliliters, of water is needed to make an 8.40 M solution of HCl acid using 180. grams of HCI ?
0 603 mL
O 41.4 mL
0 587 ml
0 24.1 mL
Answer:
0 587 mL
Explanation:
First we convert 180 grams of HCl into moles, using its molar mass:
180 g ÷ 36.46 g/mol = 4.94 mol HClNow we can use the number of moles and the given concentration to calculate the required volume, applying the definition of molarity:
Molarity = moles / litersLiters = Moles / molarity4.94 mol / 8.40 M = 0.588 LFinally we convert liters into milliliters:
0.588 L * 1000 = 588 mLThe closest answer is option C, 587 mL.
The volume needed to make an 8.40 M solution of HCl is 0.587 ml.
The correct option is C.
What is HCl?HCl is a strong acid. It is present in our stomach to help in digesting food.
Step1: covert 180 grams into moles
Molar mass of HCl is 36.46 g
[tex]\dfrac{180 g}{36.46 g/mol } = 4.94\; mol\; HCl[/tex]
Step2: calculate the molarity
[tex]\rm Molality = \dfrac{mol}{L}\\\\\rm L = \dfrac{4.94 mol }{8.40 M} = 0.588 L\\[/tex]
Covert the liters into ml
[tex]\dfrac{0.588 L}{1000} = 588 mL[/tex]
Thus, the volume of the solution is 588 ml., nearest is option C, 587 ml.
Learn more about HCl
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what plate boundary typically causes earthquakes
Answer:
Convergent Plate Boundaries
Explanation:
I hope this helps :)
Answer the following questions about the solubility of CoCO3(s). The value of Ksp for CoCO3(s) is 1.0 × 10^−10.
A. Calculate the value of [Co2+] in a saturated solution of CoCO3 in distilled water.
B. If 0.10 M of Co2+ is already present in distilled water, calculate the molar solubility of CoCO3(s).
C. Explain why CoCO3 is less soluble in distilled water that already contains Co2+
Answer:
Attached picture.
Explanation:
(1) Ksp equals the product of [Co 2+][CO3 2-]. CoCO3 is excluded from the equilibrium expression because it is a pure solid. The mole ratio of Co 2+ and CO3 2- is 1:1 so their molar solubilities are the same.
(2) There is an initial concentration of 0.10 M Co 2+ so write that in the "I" row for Co 2+ on the ICE table. When you find the zeros of the quadratic when solving for "s", take the positive value rather than the negative value because concentration cannot be negative.
(3) Extra products will cause the equilibrium to consume products and form reactants. So the reverse reaction will occur faster than the forward reaction. More products mean an increased Q value compared to K, since the numerator of [tex]K = \frac{[products]}{[reactants]}[/tex] increases.
Americium-241 undergoes radioactive decay to produce neptunium-237. Which particle needs to be added to this equation to show that the total numbers of neutrons and protons are not changed by the reaction?
Answer:
alpha particle needs to be added to the equation.
Explanation:
Given;
atomic mass of Americium = 241
atomic mass of neptunium = 237
The difference in atomic mass of the radioactive elements given is calculated as;
241 - 237 = 4
The particle with atomic mass of 4 is alpha particle usually represented with helium atom.
Am²⁴¹ -----> He⁴ + Np²³⁷
Thus, alpha particle needs to be added to the equation.
Answer:
4/2 HE
Explanation:
a p e x!