Answer:
12.99
Explanation:
A chemist dissolves 716. mg of pure potassium hydroxide in enough water to make up 130. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.
Step 1: Given data
Mass of KOH: 716. mg (0.716 g)Volume of the solution: 130. mL (0.130 L)Step 2: Calculate the moles corresponding to 0.716 g of KOH
The molar mass of KOH is 56.11 g/mol.
0.716 g × 1 mol/56.11 g = 0.0128 mol
Step 3: Calculate the molar concentration of KOH
[KOH] = 0.0128 mol/0.130 L = 0.0985 M
Step 4: Write the ionization reaction of KOH
KOH(aq) ⇒ K⁺(aq) + OH⁻(aq)
The molar ratio of KOH to OH⁻is 1:1. Then, [OH⁻] = 0.0985 M
Step 5: Calculate the pOH
We will use the following expression.
pOH = -log [OH⁻] = -log 0.0985 = 1.01
Step 6: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 -1.01 = 12.99
A thermometer containing 8.3 g of mercury has broken. What volume, in milliliters, of mercury spilled?
The volume of Mercury spilled : 0.613 milliliters
Further explanationGiven
8.3 g of Mercury
Required
The volume
Solution
Density is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
Density formula:
[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]
ρ = density
m = mass
v = volume
Density of mercury : 13.534 g/cm³
Input the value :
V = m : ρ
V = 8.3 g : 13.534 g/cm³
V = 0.613 cm³= 0.613 ml
In another experiment, a 0.150 M BF4^-(aq) solution is prepared by dissolving NaBF4(s) in distilled water. The BF4^-(aq) ions in the solution slowly react with H2O(l) in the reversible reaction represented below.
BF4-(aq) +H20(l) → BF3OH-(aq) + HF(aq)
[HF] reaches a constant value of 0.0174 M when the reaction reaches equilibrium. For the forward reaction, the rate law is rate = kf [BF4-]. The value of the rate constant kf was experimentally determined to be 9.00x10-4 min-1.
Required:
a. Calculate the rate of the forward reaction after 600 minutes.
b. A student claims that the initial rate of the reverse reaction is equal to zero. Do you agree or disagree with this claim?
Answer:
A) Forward rate = 1.1934 × 10^(-4) M/min
B) I disagree with the claim
Explanation:
A) We are told that [HF] reaches a constant value of 0.0174 M at equilibrium.
The reversible reaction given to us is;
BF4-(aq) +H20(l) → BF3OH-(aq) + HF(aq)
From this, we can see that the stoichiometric ratio is 1:1:1:1
Thus, concentration of [BF4-] is now;
[BF4-] = 0.150 - 0.0174
[BF4-] = 0.1326 M
From the rate law, we are told the forward rate is kf [BF4-].
We are given Kf = 9.00 × 10^(-4) /min
Thus;
Forward rate = 9.00 × 10^(-4) /min × (0.1326M)
Forward rate = 1.1934 × 10^(-4) M/min
(B) The student claims that the initial rate of the reverse reaction is equal to zero can't be true because at equilibrium, rates for the forward and reverse reactions are usually equal.
Thus, I disagree with the claim.
GIVING BRAINEST NOW!!! THANK YOU LUV
1. Write the terms galaxies, galaxy clusters, stars, and universe in the diagram to show which objects contain the other objects.
IT KINDA LOOKS LIKE THIs but side ways
Answer:
i dont know how exactly you want this but ill give it a go
the sun is a star, the diagram is a diagram of a galaxy, and the outside of the rings contains everything else???
Explanation:
im sorry i tried i really dont know.
Suggest why people used to believe that water was an element.
It is right? or is it ice and acid at the samee timeee?
did the mixture boil faster
Answer:
no it will take more time to boil
What type of heat transfer occurs when you touch a metal seat with your
hand and the seat feels cold?
A. Radiation
B. Convection
C. Conduction
D. Transportation
MULTIPLE CHOICE QUESTION
Popcorn popping in a pot on the stove
is an example of:
1.The Kelvin scale
2.radiation
3.conduction
4.convection
Will give Brainiest answer
Answer:
Confection
Explanation:
Answer:
2 - Radiation
Explanation:
The air above the stove is heated and because it is gas, moves upward. This is convection. The bottom of the pot and the surface of the stove are not 100% flat. In those areas where the stove and the bottom of the pot are not in contact, radiation transports heat from the stove to the heat. Which heats up the kernals.
Please help me fill in this answer........
I’ll mark brainliest
Help me please
:)
Answer:
the amount of atoms and particle I think is in here is 17 that oxygen and water can hold with the amount of barium hydrogen.
what volume of 7.25 mol/L stock solution in needed to make 3.84 L of 8.50 mol/L solution?
Answer:
4.50 L
Explanation:
First we calculate how many moles are there in 3.84 L of a 8.50 mol/L solution:
3.84 L * 8.50 mol/L = 32.64 molNow, keeping in mind that
Concentration = Mol / Volumewe can calculate the volume of a 7.25 mol/L solution that would contain 32.64 moles:
Volume = Mol / ConcentrationVolume = 32.64 mol ÷ 7.25 mol/LVolume = 4.50 LSo we could take 4.50 L of the 7.25 mol/L solution and evaporate the solvent until only 3.84 L remain.
Why does solid water (ice) float when placed in liquid water? *
Ice does not float in liquid water.
Ice is less dense than liquid water.
Ice is more dense than liquid water.
The densities of liquid water and ice are the same .
Answer:
Ice is less dense than water.
Atoms of which element can bond to each other to form chains, rings, and networks?
Select one:
O a. hydrogen
b. oxygen
c. chlorine
d. carbon
How many moles of magnesium chloride are produced when 4.39 moles of magnesium are placed in a beaker
containing only 250.0 grams of hydrochloric acid?
Answer:
[tex]n_{MgCl_2}=3.43mol MgCl_2[/tex]
Explanation:
Hello!
In this case, since the reaction between magnesium and hydrochloric acid is:
[tex]Mg+2HCl\rightarrow MgCl_2+H_2[/tex]
Whereas there is a 1:1 and 1:2 mole ratio between magnesium and magnesium chloride and hydrochloric acid and magnesium chloride respectively; it is possible to compute the yielded moles of product by each reactant and then determine which moles are correct based on the limiting reactant; therefore, we proceed as follows:
[tex]n_{MgCl_2}^{by\ Mg}=4.39molMg*\frac{1molMgCl_2}{1molMg} =4.39molMgCl_2\\\\n_{MgCl_2}^{by\ HCl}=250.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molMgCl_2}{2molHCl}=3.43mol MgCl_2[/tex]
Thus, since the hydrochloric acid yields the fewest moles of product, we infer it is the limiting reactant, so the correct number moles of magnesium chloride are 3.43 mol.
Best regards!
How many moles are in 4.30 grams of lead (Pb) ?
Answer:0.005 moles
Explanation: 4.3/207 moles = 0.005
Imagine you have an object with a non-geometric shape having a mass of 26.7 g and
a density of 0.767 g/mL. If it were placed in a graduated cylinder containing 20.0 mL
of water what would you expect the new water level to read? [Assume the sample is
completely submerged and everything is done at 25°C]
Answer:
The new reading of the water level is 54.81 mL.
Explanation:
From the question given above, the following data were obtained:
Mass of object = 26.7 g
Density of object = 0.767 g/mL
Volume of water = 20 mL
New reading of the water level =?
Next, we shall determine the volume of the object. This can be obtained as follow:
Mass of object = 26.7 g
Density of object = 0.767 g/mL
Volume of object =?
Density = mass /volume
0.767 = 26.7 / volume of object
Cross multiply
0.767 × Volume of object = 26.7
Divide both side by 0.767
Volume of object = 26.7 / 0.767
Volume of object = 34.81 mL
Finally, we shall determine the new reading of the water level. This can be obtained as follow:
Volume of water = 20 mL
Volume of object = 34.81 mL
New reading of the water level =?
New reading of the water level = (Volume of water) + (Volume of object)
New reading = 20 + 34.81
New reading of the water level = 54.81 mL
A mixture of gases contains 4.46 moles of neon (Ne), 0.74 mole of argon (Ar), and 2.15 moles of xenon (Xe). Calculate the partial pressures of the gases if the total pressure is 2.00 atm at a certain temperature.
Explanation:
The partial pressure of an individual gas is equal to the total pressure of the mixture multiplied by the mole fraction of the gas.
Total pressure = 2atm
Mole Fraction = number of moles / total number of moles
Neon
Mole Fraction = 4.46 / 7.35 = 0.607
Partial Pressure = 0.607 * 2 = 1.214 atm
Argon
Mole Fraction = 0.74 / 7.35 = 0.101
Partial Pressure = 0.101 * 2 = 0.202 atm
Xenon
Mole Fraction = 2.15 / 7.35 = 0.293
Partial Pressure = 0.293 * 2 = 0.586 atm
BRAINLIEST IF YOU GIVE ME A LEGIT ANSWER
Answer: its Important that the new cells have a copy of every chromosome so the process involves copying the chromosomes first and then carefully separating the copies to give each new cell a full set
Explanation:ye
Answer: In mitosis a cell divides to form two identical cells. It is important that the cells have a copy of every chromosome, so the process involves copying the chromosomes first and then carefully separating the copies to give each new cell a full set.
why do each of the elements react differently?
How many significant digits are in 1,000,005 micrometers
Answer:
7
Explanation:
not including the comas but if you add 4+3 it equals 7.
Answer:
7 significant figures
Explanation:
Describe how the weight of an objects influences that objects shape or design to support that weight.
(Hint: We described the legs of different sized animals. We also described the architecture of ancient buildings like the pyramids)
Answer:
The weight of the objects has a name and is "Specific weight", this is measured in several measurements but the best known is the kg.
If we relate the density of the object with the weight we will obtain a deduction of the shape of the object.
Explanation:
The object can be more or less heavy according to its density and its chemical composition.The weight is nothing more than the attraction of that object with the interior of the earth, that is why in order to know well how heavy it is, it is necessary relate the density of the object, the material that composes it, the speed of gravity (10m / s2).
This refers to the fact that a kilo of feather is not the same as a kilo of lead, each object obtains its shape according to the more weight it has and the more attraction it can make to the center of the earth.
A 1500 kg race car accelerates at a rate of about 9M /s2 as to how much force does the engine need to create for this to happen
Answer:
13500 N
Explanation:
According to newtons second law of motion
mass m =1500 Kg
a = 9m/s^2
Force F = mass m × acceleration a
F = 1500×9= 13500 N
how many grams of carbon are in 12x10^23 atoms of carbon
Answer:23.9 g
Explanation:
Grams C = (12/6.02214076)*12 = 23.9 g
There are 23.9 grams of carbon are in [tex]12*10^{23}[/tex] atoms of carbon.
As we know that, atomic mass of carbon is 12.
It means that, In one mole of carbon , 12 grams of carbon is present.
1 mole [tex]=6.022*10^{23} atoms[/tex]
In [tex]6.022*10^{23}[/tex] atoms of carbon, 12 grams of carbon is present.
So, In [tex]12*10^{23}[/tex] atoms of carbon,
[tex]=\frac{12}{6.022*10^{23} }*6*10^{23}\\\\=23.9 grams[/tex]
There are 23.9 grams of carbon are in [tex]12*10^{23}[/tex] atoms of carbon.
Learn more:
brainly.com/question/26135062
Which electron-dot structure represents a non-polar
molecule?
Answer:
CH4
Explanation:
It is a symmetrical molecule thus making it a non-polar molecule
H2(g)+p4(s)ph3(g) what the answer ?
Answer:
6H2 + P4→ 4PH3
Explanation:
Phosphorus has 4 in it and hydrogen has 3 in it. in order to balance it, we have to put 4 in front of phosphine so that the phosphorus on the product side has an equal amount as to the one on the reactant side.
the only one left to balance is hydrogen and so in order to balance it we put a 6 on h2 because the hydrogen in the product size becomes 12 (4 * 3).
therefore the hydrogen on the reactant side becomes 12 as well (6 * 2)
The balanced chemical reaction is:
[tex]6H_2(g)+P_4(s)\rightarrow 4PH_3(g)[/tex]
Explanation:
In a balanced chemical equation number of atoms of all the elements are equal on the reactant side and product side.The given equation of the chemical reaction is not balanced.[tex]H_2(g)+P_4(s)\rightarrow PH_3(g)[/tex]
Balancing the chemical reaction:
Balance the atoms of all the elements besides hydrogen and oxygen. Balance phosphorus atoms by writing 4 in front of phosphine gas on the product side.[tex]H_2(g)+P_4(s)\rightarrow 4PH_3(g)[/tex]
Now balance the hydrogen atoms. There are 12 hydrogen atoms on the product side and 2 hydrogen atoms on the reactant side. So by writing 6 in front of hydrogen gas on the reactant side.[tex]6H_2(g)+P_4(s)\rightarrow 4PH_3(g)[/tex]
So, the balanced chemical reaction is:
[tex]6H_2(g)+P_4(s)\rightarrow 4PH_3(g)[/tex]
Learn more about the balanced chemical reaction here:
brainly.com/question/23659079?referrer=searchResults
brainly.com/question/13019208?referrer=searchResults
A student titrates 0.2087 g of an unknown diprotic acid with 0.1224 M sodium hydroxide. It takes 32.47 mL of the NaOH solution to reach the endpoint. How many moles of NaOH are used in the titration
Given :
A student titrates 0.2087 g of an unknown diprotic acid with 0.1224 M sodium hydroxide.
It takes 32.47 mL of the NaOH solution to reach the endpoint.
To Find :
How many moles of NaOH are used in the titration.
Solution :
Number of moles( n ) is given by :
n = Molarity × Volume( in liters )
n = [tex]0.1224 \times \dfrac{32.47}{1000}\ moles[/tex]
n = 0.00397 moles.
Therefore, moles of NaOH are used in the titration is [tex]3.97\times 10^{-3} \ moles[/tex].
The number of moles of NaOH are used in the titration is [tex]3.97 \times 10^{-3}[/tex] moles.
The calculation is as follows;The number of moles should be
[tex]= molarity \times volume\\\\= 0.1224 \times \frac{32.47}{1000}[/tex]
= 0.00397 moles.
learn more: https://brainly.com/question/2386757?referrer=searchResults
A__is a small unit of matter.
A energy
B particle
C diffusion
Answer:
b
Explanation:
A 45.0 g sample of a metal at 85.6 °C is placed in 150.0 g of water at 24.6 °C. The final temperature of the system is 28.3 °C. Calculate the specific heat of the metal.
Answer:
904.014 j/kgk
Explanation:
Mass of metal = 45g
Temperature of metal = 85.6°
Mass of water = 150
Temperature of water = 24.6
Final temperature of system = 28.3
Heat lost by metal = Heat gained by water
m1 * c1 * dt = m2 * c2 * dt
Q = quantity of heat
Q = m*c*dt
dt = change in temperature
dt of water = 28.3 - 24.6 = 3.7
dt of metal = 85.6 - 28.3 = 57.3
Specific heat capacity of water, c = 4200
(45 * 10^-3) * c * 57.3 = (150 * 10^-3) * 4200 * 3.7
2.5785c1 = 2331
c1 = 2331 / 2.5785
= 904.01396
= 904.014 j/kgk
Can Someone help me with this problem?
Compared to the cells in a healthy body, Elisa’s cells are getting far fewer _________ molecules.
Answer:
Glucose
Explanation:
This question is taken from a story that's on the internet titled "diagnosing Elisa".
Now, the diagnosis of Elisa found out that Elisa felt tired because her cells were not getting the daily amount of molecules they required from food and air and this made her cells not to function, grow & repair efficiently. In addition, the diagnoses further explained lack of molecules to mean that although that Elisa's cells were getting sufficient oxygen and amino acids molecules, but did not get sufficient glucose molecules.
A solution is made by mixing of chloroform and of heptane . Calculate the mole fraction of chloroform in this solution. Be sure your answer has the correct number of significant digits.
Answer:
0.53
Explanation:
A solution is made by mixing 42 g of chloroform (CHCl₃) and 31 g of heptane (C₇H₁₆). Calculate the mole fraction of chloroform in this solution. Be sure your answer has the correct number of significant digits.
Step 1: Calculate the number of moles of chloroform
The molar mass of CHCl₃ is 119.38 g/mol.
42 g × 1 mol/119.38 g = 0.35 mol
Step 2: Calculate the number of moles of heptane
The molar mass of C₇H₁₆ is 100.20 g/mol.
31 g × 1 mol/100.20 g = 0.31 mol
Step 3: Calculate the total number of moles
We will use the following expression.
n = nCHCl₃ + nC₇H₁₆ = 0.35 mol + 0.31 mol = 0.66 mol
Step 4: Calculate the mole fraction of chloroform
We will use the following expression.
χ(CHCl₃) = nCHCl₃ / n
χ(CHCl₃) = 0.35 mol / 0.66 mol = 0.53
HELP
Question 17
How many nitrogen atoms are in a 2.51 mol sample of N2O?
Link to Periodic Table of the Elements
09.06 x 1024
O 4.17 x 10 24
O 3.02 x 1024
O 1.51 X 1024
ELP BRAINLIEST
Answer:
3.02× 10²⁴ atoms
Explanation:
Given data:
Number of nitrogen atoms = ?
Number of moles of N₂O = 2.51 mol
Solution:
1 mole contain 2 mole of nitrogen atoms.
2.51 × 2 = 5.02 mol
According to Avogadro number,
1 mole = 6.022 × 10²³ atoms
5.02 mol × 6.022 × 10²³ atoms / 1 mol
30.2 × 10²³ atoms
3.02× 10²⁴ atoms
