Weak base: [OH⁻] = √Kb.C
pKb = 4.2
[tex]\tt Kb=10^{-4.2}[/tex]
c = concentration
MM Amphetamine (C9H13N) = 135.21 g/mol
c = 215 mg/L = (0.215 g : 135,21 g/mol) / L = 0.00159 mol/L = 1.59 x 10⁻³ mol/L
[tex]\tt [OH^-]=\sqrt{10^{-4.2}\times 1.59\times 10^{-3}}=3.17\times 10^{-4}[/tex]
pOH = 4 - log 3.17
pH = 14 - (4 - log 3.17)
pH = 10 + log 3.17 = 10.50
A 5.00 L flask at 25˚ C contains 0.200 mol of Cl2 . What is the pressure in the flask?
The pressure of a 5.00 L flask at 25˚ C that contains 0.200 mol of Cl2 is 0.98atm.
How to calculate pressure?The pressure of a gas can be calculated by using the following expression:
PV = nRT
Where;
P = pressureV = volumen = number of molesR = gas law constantT = temperatureP × 5 = 0.2 × 0.0821 × 298
5P = 4.893
P = 4.893 ÷ 5
P = 0.98atm
Therefore, the pressure of a 5.00 L flask at 25˚ C that contains 0.200 mol of Cl2 is 0.98atm.
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Answer:
Your answer would be:
0.98atm.
Explanation:
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#TheWizzer
PLEASE HELP!!!!!!!
You compare the gas generated from a reaction using two antacid tablets with the gas generated from a reaction using four antacid tablets (consider the antacid as the limiting reagent).
At constant pressure and temperature, how do the volumes of the gases compare?
The two reactions produce the same amount of gas.
The gas generated by four antacid tablets has a smaller volume.
The gas generated by two antacid tablets has a smaller volume.
Answer: The gas generated by two antacid tablets has a smaller volume.
Explanation:
Since the antiacid is the limiting reagent, we know that the more tablets there are, the more gas there will be.
This means that there will be more gas generated by the four antiacid tablets when compared to the two antiacid tablets, which gives us that the gas generated by the two antiacid tablets has a smaller volume.
If 30 grams of KCl is dissolved at 10°C, how many additional grams would be needed to make the solution saturated at 60°C? * Captionless Image 45g 20g 15g 75g
If 30 grams of KCl is dissolved at 10°C, 14 g of KCl should be added to make a saturated solution at 60 °C.
What is a saturated solution?A saturated solution is a solution in which there is so much solute that if there was any more, it would not dissolve. Its concentration is the same as the solubility at that temperature.
Step 1. Calculate the mass of water.At 10 °C, the solubility is 31.2 g KCl/100 g H₂O.
30 g KCl × 100 g H₂O/31.2 g KCl = 96 g H₂O
Step 2. Calculate the mass of KCl required to prepare a saturated solution at 60 °C.At 60 °C, the solubility is 45.8 g KCl/100 g H₂O.
96 g H₂O × 45.8 g KCl/100 g H₂O = 44 g KCl
Step 3. Calculate the mass of KCl that must be added.44 g - 30 g = 14 g
If 30 grams of KCl is dissolved at 10°C, 14 g of KCl should be added to make a saturated solution at 60 °C.
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1) Identify two different mineral nutrients present in the fertilizer
that helped the plant recover. Then, describe how each nutrient
benefits the plant.
The two different mineral elements that a fertilizer can contain are:
Phosphorus - build up of nucleic acid and ATPNitrogen- synthesis of proteinsWhat are fertilizers?Fertilizers are chemical substances added to the soil in order to improve crop growth and development.
Fertilizers are artificially made to contain mineral elements that are needed by the plants. Some of the mineral elements are as follows:
PhosphorusNitrogenPottasiumPhosphorus helps in the build up of nucleic acids and ATP for energy. Nitrogen is useful in the synthesis of proteins.Learn more about minerals at: https://brainly.com/question/18078524
Answer:
is the answer above right? im literally struggling rn
Explanation:
Determine the molar solubility of BaF2 in a solution containing 0.0550 M LIF. Ksp (BaF2) = 2.45 x 10^-5
Answer:
8.1*10^-3 or 0.00809917
Explanation:
Step 1: Identify the common ion
LiF and BaF2 both share the ion F^- therefore we can interchange the molarity of LiF for F.
Step 2: Set up a balanced equation
BaF2---Ba2+ + 2F
Step 3: Set up a solubility ice table
initial- Ba^2+: 0 2F: 0.0550
change- S 2F: S^2(exponent is result of coefficient)
Step 4: Set up Ksp equation
2.45*10^-5=[S][S]^2
Step 5: Plug in values
2.45*10^-5=[S][0.0550]^2
S=8.1*10^-3
Match each form of energy with its definition
Chemical energy
Kinetic energy
Potential energy
mechanical energy
energy of motion ----
the energy of the bonds between atoms-----
the sum of an object's kinetic and potential energies----
stored energy based on position or arrangement-------
Answer:
energy of motion is kinetic
energy of Bond between atom chemical energy
stored energy based on position or arrangement-potential
the sum of an object's kinetic and potential energies----mechinical
23.4 grams of Al2(SO3)3 is yielded through a chemical reaction. How many moles is this?
Answer:
.0796 mole
Explanation:
Al2 (SO3)3 add the molecular weights
2 * Al = 2 * 26.982 +
3 * S = 3 * 32.06 +
9 * O = 6 * 15.999 = 294.135 gm per mole
Now... you have 23.4 grams of this substance
23.4/294.135 = .0796 mole
EDITED !
Set up a cell that has a Mg electrode in a 1.0 M aqueous Mg2+ solution on the left side and a Cu electrode in a 1.0 M aqueous Cu2+ solution on the right side. Add the salt bridge. What is the balanced net ionic equation for this reaction? Include physical states.
The cell notation is; Cu^2+(aq)/Cu(s)//Mg(s)/Mg^2+(aq). The standard cell notation helps us to write the cell equation easily.
What is electrochemical cell?The electrochemical cell involves the transformation of chemical energy to electrical energy in an electrochemical cell. The two electrodes involved are the cathode and the anode.
In this case, the Mg is the anode and the Cu is the cathode hence the cell notation is; Cu^2+(aq)/Cu(s)//Mg(s)/Mg^2+(aq).
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What is the chemical name
for ca2 and clo3-
Answer:
Calcium chlorate | Ca(ClO3)2 - PubChem.
Explanation:
What is the most metallic character with low ionization energies
Answer:
Metals tend to lose electrons in chemical reactions, as indicated by their low ionization energies. Within a compound, metal atoms have relatively low attraction for electrons, as indicated by their low electronegativities.
XeF6
formula mass =
molar mass =
Answer:
Xenon hexafluoride's molar mass is about 245.28 g/mol
Formula mass is about 245.28 u.
Explanation:
So we want to find the formula mass of the XeF6 and there is a special formula for that.
You have to multiply the number of each element in XeF6 by the element's atomic mass.
The atomic mass of Xe is 131.293, and F's atomic mass is multiplied by 6, due to the 6 at the bottom. F's atomic mass is 18.998403, so we multiply the atomic number by 6, which would equal 113.990418. Round if you want, but it would equal mostly the same thing. Add it up to get ≈245.28, which is the same thing.
Therefore the formula mass of XeF6 is 245.28 u.
why is it necessary to standardize a secondary standard before use?
As the name implies, a secondary standard is used by standard laboratories, which include companies involved in the preparation of reagents and kits, as well as laboratories responsible to produce quality control material for use by other laboratories. They use the primary standard as the primary calibrator or primary reference material, and they calibrate their instruments against it. Smaller labs use secondary standards to calibrate control material for analysis of unknown concentrations. For smaller labs, secondary standard serves as an external quality control. As a result, it is essential that the secondary standard be standardized against the primary standard before it can be applied.
I hope this helps you
:)
(113) Fe, Co, and Ni are in a category of metals best known as
(A) Transition metals
(B) Alkali metals
(C) Rare metals
(D)Main group metals
(
Answer:
A
Explanation:
iron, cobalt and nickel are all transition metals
How many R.P.'s is equivalent to 0.780 g of Na₂CO₂?
Answer:
pbo2+cl-=clo-+pb(oh)2
Explanation:
balance by ion electron
Remove all the tape pieces from part A, and throw them in the trash. Next, follow these steps to compare pieces of sticky tape that have different charges:
Tear off two pieces of tape that are about 15 cm (6 inches) long. Similar to part A, fold under a half inch of each piece to make the strips easier to pull off.
Stick one of the pieces onto the tabletop. Smooth the tape down.
Stick the second piece of tape onto the tape piece you just placed. Do not cover the tab of the first piece of tape.
Grasp one tape tab in each hand. Carefully pull both pieces off the table and separate them. Turn the non-sticky sides of the tape toward each other.
What do you observe? If there’s an interaction, explain whether the tape pieces attract or repel each other. (ANSWER ASAP)
The interaction which will occur when the non sticky tape pieces are turned towards each other is attraction.
What is Attraction?This involves the coming together of objects as a result of a force. When non-sticky sides of the tape are brought towards each other attraction takes place due to the sticky content.
This however wears off after some time thereby making it the most appropriate choice.
Read more about Attraction here https://brainly.com/question/16033085
A 25 L tank of oxygen under a pressure of.80 atm would require what pressure to
decrease the volume to 1.0 L?
Answer:
20 atm
Explanation:
Use the equation P1 x V1 = P2 x V2.
1) Rearrange the equation with algebra to solve for P2.
P2 = (P1 x V1)/ V2
2) Plug in to the equation where V1 = 25L, P1 = 0.80 atm, and, V2 = 1 L
P2 = (25L x 0.80 atm)/ 1L
3) Solve: P2 = 20 atm
The pressure required to reduce the oxygen's volume to 1 L would be 20 atm.
Which of the following represents the velocity of a moving object?
Select one:
40 m north.
40.
40 m/s north.
40 m/s.
Answer:
The correct answer would be 40 m/s
Explanation:
The reason 40 m/s is the correct answer is because m/s stands for meters per second.
Hope this helps you with what you're working on! :D
Answer:
40 m/s north
Explanation:
Velocity is a vector quantity, so it have both direction and magnitude.
Calculate how many grams of oxygen form when 2.72 g of KCIOg reacts completely given the
following equation:
2 KCI03 (s)
- 2 KCI (s) + 302 (g)
1.06g
Please refer to the image attached.
You first find the number of moles (n) for KClO3 as you have been given the mass. So n = mass/Mr gives you the moles that is 0.022 mol
Next you use the ratio 2:3 as per the equation where it's 2KClO3 ---> 3O2 so you just cross multiply and get the moles for oxygen.
Now that you know the number of moles for oxygen, you can use the same moles equation that you used earlier to find the mass. mass=n×Mr and so you get the answer as 1.06g of oxygen.
Which color object would be the hottest? A violet object, a red object or a green object? Why?
Answer:
A Violet object
Explanation:
An Violet object attracts the heat after white objects, followed by orange, yellow, green, blue, indigo and violet, which attracts the most heat of any visible color other than black.
Why is an enzyme in a chemical reaction like a lock and key?
A. The active site and the substrate fit perfectly together, and when they do, they unlock the chemical reaction.
B. The non-reactive site and the substrate fit perfectly together, and when they do, they unlock the chemical reaction.
C. None of these
D. The nucleoid and Golgi Apparatus fit perfectly together, and when they do, they unlock the chemical reaction.
E. The active site and the cell membrane fit perfectly together, and when they do, they unlock the chemical reaction.
Answer:
A
Explanation:
the enzyme is substrate specifix coz of this trait
1. List the actual volume of titrant needed to produce a color change for Sample A and Sample B. Answer: Volume of titrant needed to produce a color change for Sample A:\ ml Volume of titrant needed to produce a color change for Sample B: ml
Answer: B Hope this helps :)
One material property that is widely used and recognized is the strength of a material. But what does the word "strength" mean? "Strength" can have many meanings, so let us take a closer look at what is meant by the strength of a material. We will look at a very easy experiment that provides lots of information about the strength or the mechanical behavior of a material, called the tensile test.
The basic idea of a tensile test is to place a sample of a material between two fixtures called "grips" which clamp the material. The material has known dimensions, like length and cross-sectional area. We then begin to apply weight to the material gripped at one end while the other end is fixed. We keep increasing the weight (often called the load or force) while at the same time measuring the change in length of the sample.
Explanation:
Sodium hydroxide (0.400 mol) is allowed to react with an excess of sulfuric acid. How many moles of
sodium sulfate could be recovered from the products?
NaOH + H2SO4 → Na2SO4 + H20
Answer:
2 moles
Explanation:
In this reaction, the stoichiometry (mole ratio) is 1 mole of sulfuric acid reacting with 2 moles of sodium hydroxide (1:2 ratio)
Complete this example: A 0.67 molal solution was
made by dissolving glucose in water. The boiling
point of pure water is 100.00°C. The boiling point
constant for water is 0.51°C kg/mol.
on
the
Set up the problem.
• 4T2 = (0.51°C•kg/mole)(0.67 m)
of
• What is the 473 value?
vc
• What is the boiling point for the glucose
solution?
УРС
Answer:
A then C
Explanation:
Answer:
a,c
Explanation:
what are chemical reaction
Example:-
Burning of waxWe cannot pull back the reaction to get wax back .
Answer:
Explanation:
The permanent change in which a new substance is formed is called a chemical reaction.
For example:
i)Burning of wood
ii)Cooking rice
iii)Forming curd from milk
The burning of wood is a chemical reaction because it is a permanent change and it cannot be reversed. Once it is done, it is over it can't be done again. And in the case of example iii, the milk turns into curd by chemical reaction. A new substance i.e curd is formed from the milk.
Hope you understood!
What metal speeds up rusting
Answer:
Vinegar
Explanation:
What liquid makes metal rust the fastest? Vinegar speeds up rusting because it contains a dilute form of acetic acid; positive hydrogen ions in the acid remove electrons from iron, ionizing it and making it susceptible to rust. How do you rust metal quickly?
Answer:
iron, especially if it is exposed to water and oxygen
What is added to balance hydrogen and oxygen atoms in an oxidation-
reduction reaction in basic solution?
A. OH and H2O
B. Ht and H20
C. H2 and 02
D. OH and Ht
Answer:
OH^- and H_2O
Explanation:
Remember these things about basic and acidic medium
In acidic medium we add H+ to balance Hydrogen and H_2O for OxygenIn basic we add OH- which turns H+ to waterThe ground electron configuration of a Tc atom is (Kr) 5s2 4d5. What is the electron configuration of a Tc3 ion
Answer:
2:1 of Tc in the periodic table
A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is a stainless-steel cylinder that measures wide 22cm and 26.4 high. The maximum safe pressure inside the vessel has been measured to be 6.30mpa.
For a certain reaction, the vessel may contain up to .537kg of dinitrogen monoxide gas. Calculate the maximum safe operating temperature the engineer should recommend for this reaction. Write your answer in degrees Celsius. Be sure your answer has the correct number of significant digits.
The maximum safe operating temperature for this reaction is equal to 895°C.
Given the following data:
Width of cylinder = 22 cm.Height, h = 26.4 cm.Maximum safe pressure = 6.30mpa.Mass = 0.537 kg.Scientific data:
Ideal gas constant, R = 8.314 L-kPa/Kmol.Molar mass of of dinitrogen monoxide ([tex]N_2F_2[/tex]) gas = 66 g/mol.Radius, r = [tex]\frac{width}{2} =\frac{22}{2} =11\;cm[/tex]
How to calculate the maximum safe operating temperature.First of all, we would determine the volume of the stainless-steel cylinder by using this formula:
[tex]V=\pi r^2 h\\\\V = 3.142 \times 11^2 \times 26.4\\\\[/tex]
Volume, V = 10,036.81 [tex]cm^3[/tex].
In liters, we have:
Volume, V = 10.04 Liters.
Next, we would determine the number of moles of dinitrogen monoxide ([tex]N_2F_2[/tex]) gas:
[tex]Number \;of \;moles = \frac {mass}{molar\;mass}\\\\Number \;of \;moles = \frac {537}{66}[/tex]
Number of moles = 8.136 moles.
Now, we can solve for the maximum safe operating temperature by applying the ideal gas equation:
[tex]PV=nRT\\\\T=\frac{PV}{nR} \\\\T=\frac{6.30 \times 10^3 \times 10.04}{8.136 \times 8.314}\\\\T=\frac{60541.2}{67.6427}[/tex]
T = 895.02 ≈ 895°C.
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what is the volume of
NH4 NO3(s) — N2O(g) + 2H2O(g)
Answer:
Explanation:
NH4NO3(s) N2O(g) + 2H2O(g) What is the total volume of gases produced at 546 K and 1.00 atm pressure when 240 g of ammonium nitrate undergoes the above decomposition reaction? A) 9 × 22.4 L B) 3 × 22.4 L C) 12 × 22.4 L D) 18 × 22.4 L E) 6 × 22.4 L
how can the ph of antiacid table de determine in laboratory
Answer:
Antacids are bases that react stoichiometrically with acid. The number of moles of acid that can be neutralized by a single tablet of a commercial antacid will be determined by back titration.
Correct me if i'm wrong, Hope This helps
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