Answer:
See explanation
Explanation:
Number of moles of Cl2 = 0.71g/71g/mol = 0.01 moles
Number of moles = 1.0 g/38g/mol = 0.02 moles
Total = 0.01 + 0.02 = 0.03 moles
From the ideal gas equation;
PV=nRT
P=?
V= 258 ml
n= 0.03 moles
T= 296 K
P= nRT/ V
P= 0.03 × 0.082 × 296/258
P= 0.003 atm
Partial pressure Cl2 = 0.01/0.03 × 0.003 atm = 0.001 atm
Partial pressure = F2 = 0.02/0.03 × 0.003atm = 0.002 atm
If you have access to stock solutions of 1.00 M H3PO4, 1.00 M of HCl, and 1.00 M NaOH solution, (and distilled water of course), what volumes of each would you mix before diluting to a final volume of 2.00 L to prepare 2.00 L of pH 7.40 buffer with a final total concentration of 50 mM of phosphorous contains species (e.g. so that [H3PO4] [H2PO4 - ] [HPO4 2- ] [PO4 3- ]
Answer:
0.10L of 1.00M of H₃PO₄ and 0.1613L of 1.00M NaOH
Explanation:
The pKa's of phosphoric acid are:
H₃PO₄/H₂PO₄⁻ = 2.1
H₂PO₄⁻/HPO₄²⁻ = 7.2
HPO₄²⁻/PO₄³⁻ = 12.0
To make a buffer with pH 9.40 we need to convert all H₃PO₄ to H₂PO₄⁻ and an amount of H₂PO₄⁻ to HPO₄²⁻
To have a 50mM solution of phosphoures we need:
2L * (0.050mol / L) = 0.10 moles of H₃PO₄
0.10 mol * (1L / mol) = 0.10L of 1.00M of H3PO4
To convert the H₃PO₄ to H₂PO₄⁻ and to HPO₄²⁻ must be added NaOH, thus:
H₃PO₄ + NaOH → H₂PO₄⁻ + H₂O + Na⁺
H₂PO₄⁻ + NaOH → HPO₄²⁻ + H₂O + Na⁺
Using H-H equation we can find the amount of NaOH added:
pH = pKa + log [A⁻] / [HA] (1)
Where [A-] is conjugate base, HPO₄²⁻ and [HA] is weak acid, H₂PO₄⁻
pH = 7.40
pKa = 7.20
[A-] + [HA] = 0.10moles (2)
Replacing (2) in (1):
7.40 = 7.20 + log 0.10mol - [HA] / [HA]
0.2 = log 0.10mol - [HA] / [HA]
1.5849 = 0.10mol - [HA] / [HA]
1.5849 [HA] = 0.10mol - [HA]
2.5849[HA] = 0.10mol
[HA] = 0.0387 moles = H₂PO₄⁻ moles
That means moles of HPO₄²⁻ are 0.10mol - 0.0387moles = 0.0613 moles
The moles of NaOH needed to convert all H₃PO₄ in H₂PO₄⁻ are 0.10 moles
And moles needed to obtain 0.0613 moles of HPO₄²⁻ are 0.0613 moles
Total moles of NaOH are 0.1613moles * (1L / 1mol) = 0.1613L of 1.00M NaOH
Then, you need to dilute both solutions to 2.00L with distilled water.
What is the charge of an element with 15 protons, 19 neutrons and 18 electrons?
Answer:
negative
Explanation:
18 negative
19 neutral
10 positive
there are are more negative
Britney found an irregularly shaped metal object on the beach that has a mass of 232.5 grams. To determine the volume, she partially filled a cylindrical water bottle and dropped the object in. The water level in the bottle rose by 1.2 cm. The bottle has a diameter of 5 cm. Calculate the density of the metal to determine what type of metal Britney found. Densities, measured in grams per cubic centimeters, g cm3 , for some common metals are listed.
The question is incomplete, the complete question is;
Britney found an irregularly shaped metal object on the beach that
has a mass of 232.5 grams. To determine the volume, she partially
filled a cylindrical water bottle and dropped the object in. The
water level in the bottle rose by 1.2 cm. The bottle has a diameter
of 5 cm. Calculate the density of the metal to determine what type
of metal Britney found. Densities, measured in grams per cubic
centimeter, g
cm3
, for some common metals are listed.
• Copper: 8.86 g
cm3
• Bronze: 9.87 g
cm3
• Silver: 10.5 g
cm3
• Gold: 19.3 g
cm3
Select the word that correctly completes the sentence.
Based on the density of the metal, it is most likely that the metal Britney
found is _______________.
\ copper
\ bronze
\ silver
\ gold
Answer:
Bronze: 9.87 g
bronze
Explanation:
We know that the volume of the liquid = the volume of the object
This is because the object will cause the liquid to occupy its own volume of the container.
Now; area of the container = πr^2 = 3.142 * (5/2)^2 = 19.635 cm^2
Volume of the liquid = volume of the sold = 19.635 cm^2 * 1.2 cm= 23.562cm^3
Now given that;
Density = mass/volume = 232.5 g/23.562cm^3 = 9.87 g/cm^3
A scientist wants to make a solution of tribasic sodium phosphate, Na3PO4, for a laboratory experiment. How many grams of Na3PO4 will be needed to produce 725 mL of a solution that has a concentration of Na ions of 1.50 M
Answer:
178.35g
Explanation:
Molarity of a solution can be calculated using the formula:
Molarity = number of moles ÷ volume
Based on the information provided in this question, molarity (M) of the solution = 1.50 M, volume = 725 mL = 725/1000 = 0.725L, n = ?
1.50 = n / 0.725
n = 1.50 × 0.725
n = 1.0875mol
Molar mass of Na3PO4
23(3) + 31 + 16(4)
= 69 + 31 + 64
= 164g/mol
Mole = mass ÷ molar mass
1.0875 = mass/164
mass = 178.35g
what is the correct meaning of the word catapult?
example :
mounting tension between england and the colonies helped catapult washingtons rank in the continental army.
a. hamper
b. improve
c. propel
d. define
Answer:
A. hamper
Explanation:
i did this question before.
Answer:
Improve
Explanation:
They improved Washington's rank so that he could rise to the top.
In a polar reaction mechanism, the atom that gives away electrons in a neutral nucleophile will end up as a(n):
The question is incomplete, the complete question is shown in the image attached.
Answer:
Cation
Explanation:
In a polar reaction mechanism, a specie must give out electrons and another specie must accept those electrons.
The specie that gives out electrons becomes electron deficient and positively charged so we refer to such a specie as a cation.
Hence, the specie that looses electrons becomes a cation.
ATOMS
define and describe?
classify it , draw it and label it
how does it relate to your life?
if it didn't exist how would life be different?
an oxygen tank used for scuba diving has. avolume of 12.0 L .If the pressure of the tank is known to be 204.047 atm and the temperature is 22.0 C(295 K), how many moles of oxygen are contained in the tank
Answer: 101 moles of oxygen are contained in the tank
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 204.047 atm
V = Volume of gas = 12.0 L
n = number of moles = ?
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]22.0^0C=(22.0+273)K=295K[/tex]
[tex]n=\frac{PV}{RT}[/tex]
[tex]n=\frac{204.047atm\times 12.0L}{0.0821 L atm/K mol\times 295K}=101moles[/tex]
Thus 101 moles of oxygen are contained in the tank
Classify each solvent as protic or aprotic. a. (CH3)2CHOH c. CH2Cl2 e. N(CH3)3 b. CH3NO2 d. NH3 f. HCONH2
Answer:
The protic solvents are (CH3)2CHOH, NH3, and HCONH2
The aprotic solvent are CH3NO2, CH2Cl2, and N(CH3)3
Explanation:
A protic solvent is a solvent that has a hydrogen atom bound to an oxygen (O), a nitrogen (N), or fluoride (F). Generally, any solvent that contains a labile H⁺ is called a protic solvent.
a. (CH3)2CHOH
(CH3)2CHOH is a protic solvent because one of the hydrogens is bound to oxygen (O)
b. CH3NO2
CH3NO2 is an aprotic (i.e not a protic solvent) solvent because all the hydrogens are bound to carbon.
c. CH2Cl2
CH2Cl2 is an aprotic solvent because all the hydrogens are bound to carbon.
d. NH3 is a protic solvent because all the hydrogens are bound to Nitrogen (N)
e. N(CH3)3 is an aprotic solvent because all the hydrogens are bound to carbon
f. HCONH2 is a protic solvent because two of the hydrogens are bound to Nitrogen (N)
PLZ HELP ME!!!!!! BEING TIMED!!!!!
Answer:
3 one
Explanation:
Which feature do all adult echinoderms have?
O moveable spine
O muscular foot
O mantle
O endoskeleton
Answer:
endoskeleton i think
Explanation:
What is the mass of 1.33 moles of Ba3(PO4)2?
Choices:
108 g
801 g
659 g
801 mol
Please help :(
Answer:
801 g
Explanation:
From the question given above, the following data were obtained:
Number of mole of Ba₃(PO₄)₂ = 1.33 moles
Mass of Ba₃(PO₄)₂ =?
Next, we shall determine the molar mass of Ba₃(PO₄)₂. This can be obtained as follow:
Molar mass of Ba₃(PO₄)₂ = (137.3×3) + 2[31 + (4×16)]
= 411.9 + 2[31 + 64]
= 411.9 + 2[95]
= 411.9 + 190
Molar mass of Ba₃(PO₄)₂ = 601.9 g/mol
Finally, we shall determine the mass of Ba₃(PO₄)₂. This can be obtained as follow:
Number of mole of Ba₃(PO₄)₂ = 1.33 moles
Molar mass of Ba₃(PO₄)₂ = 601.9 g/mol
Mass of Ba₃(PO₄)₂ =?
Mole = mass /Molar mass
1.33 = Mass of Ba₃(PO₄)₂ / 601.9
Cross multiply
Mass of Ba₃(PO₄)₂ = 1.33 × 601.9
Mass of Ba₃(PO₄)₂ = 801 g
What is the density of methane, CH4 in a vessel where the pressure is 910 torr and the temperature is 255 K
Answer: Density of methane is 0.92 g/L
Explanation:
The relation between density and molar mass is :
[tex]d=\frac{PM}{RT}[/tex]
where , d = density
P = pressure = 910 torr = 1.20 atm (760 torr=1atm)
M = molar mass = 16 g/mol ( for methane)
R = gas constant = [tex]0.0821Latm/Kmol[/tex]
T = temperature = 255 K
Putting the values :
[tex]d=\frac{1.20atm\times 16g/mol}{0.0821Latm/Kmol\times 255K}=0.92g/L[/tex]
Thus density of methane is 0.92 g/L
methods for maximizing crystal growth , explain how?
Answer:
meth
Explanation:
YOu get chemicals and mix them together yes you do
The formation of chemical bonds from separated atoms 1. is never spontaneous. 2. increases entropy. 3. is always endothermic. 4. is always exothermic. 5. may be either endothermic or exothermic.
Answer:
is always exothermic
Explanation:
You see, whether a process is endothermic or exothermic depends on the result of the operation; ΔHreaction= ΔHproducts - ΔHreactants.
If the enthalpy of reactants exceeds that of the products, then the process is exothermic.
We should remember that the energy of isolated atoms is always higher than the energy of the compound formed when the atoms bond together. Hence bond making is an exothermic process.
Energy is used to form bonds and released when they are broken, bond-breaking is considered to be endothermic. Additionally, the creation of bonds is typically an exothermic process. The formation of chemical bonds from separated atoms is exothermic. The correct option is 4.
When bonds are created in the products of exothermic processes, more energy is produced than is required to break the bonds between the reactants. The temperature of the reaction mixture rises as a result of exothermic reactions. Endothermic chemical processes are those that generally absorb (or use) energy.
An attraction between atoms or ions is referred to as a chemical bond. Atoms trade or exchange valence electrons to create bonds.
Thus the correct option is 4.
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The process by which cells divide is called
A
O replication
B.
mitosis
C.
respiration
D.
photosynthesis
the answer is mitosis
Is sound matter?? Please help me..
Answer:
No sound Is not matter Sound and light are not considered matter and was never matter
Explanation:
Hope this hope helps
what problems occurs if the firework mixture is not pure(they are dirty or contaminated?
Firework mixture is made up with potassium nitrate and other toxic chemicals. They produce harmful wastes to the atmosphere. If they are contaminated, they make release very dangerous explosives by unwanted reactions.
What are explosives?Explosives are chemicals releasing lot of heat energy to the surrounding upon decomposition. Nitrogen compounds, hydrogen etc are explosive and they will explode in air or water.
Chemicals have to handled carefully and stored as per the conditions based on their chemical and physical properties. Some of them may easily corrode. Some may rapidly reacts with water or air and some may explode in air.
Explosive chemicals causes atmospheric pollution as well as health risk by releasing hazardous chemicals. If they are contaminated then there may occur some unwanted reaction and it will make the risk intense by producing toxic gases.
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Based on your observations from the glowing splint test with oxygen gas, briefly explain why liquid oxygen is a very hazardous substance
Answer:
liquid oxygen is highly flammable
Explanation:
near any source of heat. liquid oxygen can explode to flames thus being hazardous
what term is best described as the logarithmic measure of the concentration of hydronium ions in a solution
Answer:
pH
Explanation:
We define the pH of a solution as the negative logarithm of hydronium ions concentration in solution.
Thus when we want to define pH mathematically, we write;
pH = - log {H3O^+]
Where;
{H3O^+] means the concentration of hydronium ions in solution.
1. Which of the following would be an example of spontaneous
generation?
Answer:
This is the idea of spontaneous generation, an obsolete theory that states that living organisms can originate from inanimate objects. Other common examples of spontaneous generation were that dust creates fleas, maggots arise from rotting meat, and bread or wheat left in a dark corner produces mice
Explanation:
hope you like my answer
Which of the following subatomic particles gives the nucleus of an atom its mass?
O both protons and neutrons
O electrons only
O neutrons only
O protons only
In an atom, the number of protons equals the number of
nuclei
electrons
neutrons
isotopes
Answer:
Electrons
Explanation:
The reactants are
A
the substances present when the reactions begins.
B
the substances present when the reaction is complete.
C
the properties that change after the reaction.
D
the energy that is released or stored during the reaction.
A is the answer! A chemical reaction always starts with the reactants and ends with a product!
Hope this helps x :)
Explanation:
The reactants are simply the substances present when a reaction begins.
Reactants are as opposed to products. The latter are substances that are present when a reaction is complete.
Reactants generally undergo chemical changes before they can form products. The chemical changes involve the breakage of old and the formation of new bonds among atoms of different elements that make up the reactants.
Reactants also need to summon an energy barrier before products can be formed. the energy barrier is known as activation energy.
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Which cause of wildfires is least likely to lead to catastrophic results
O arson
Olightning strike
O controlled burn
O unattended campfire
The controlled burn cause of wildfires is least likely to lead to catastrophic results. Therefore, option (C) is correct.
What is controlled burning?A controlled burn is a fire set intentionally for purposes of forest management, prairie restoration, farming, or greenhouse gas. A controlled burn refers to the intentional burning of slash, fuels through burn piles.
Controlled burning can be done during the cooler months to reduce fuel buildup and reduce the likelihood of serious hotter fires. Controlled burning enhances the germination of desirable forest trees, and exposes soil mineral layers which expand seedling vitality.
Controlled burning is also useful in agriculture as it is often referred to as slash and burns. It is one component of shifting cultivation, as a section of field preparation for planting called field burning. This technique is utilized to clear the land of any existing crop residue and kill weeds and weed seeds.
Field burning is less expensive but because it forms smoke and air pollutants, its use is not common in agricultural areas.
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Evaluate (754 mm)/(41 s) to three significant figures and express answer in SI units using an appropriate prefix.
1.14m x MG is the answer
How does the number of molecules in 1 mol of oxigen compare with the number of molecules in 1 mol of nitrogen?
Answer:
They are the same.
Explanation:
Hello!
In this case, according to the Avogadro's number, we take into account that for molecules such as gaseous oxygen (O₂) and nitrogen (N₂), we realize that 1 mole of these contain 6.022x10²³ moles of molecules; as we are given 1 mol each, we notice they both have 6.022x10²³ molecules, therefore, they number of molecules is the same because they have the same number of moles.
Best regards!
On a mission to a newly discovered planet, an astronaut finds gallium abundances of 60.11 % for 69Ga and 39.89 % for 71Ga. What is the atomic mass of gallium for this location
Answer:
69.79
Explanation:
According to this question, Gallium element (Ga) has two isotopes namely: 69Ga and 71Ga respectively.
- Isotope 69Ga contains a percent abundance of 60.11 %, the decimal abundance= 0.6011
- Isotope 71Ga contains a percent abundance of 39.89 %, the decimal abundance = 0.3989
Atomic mass of Ga = (mass of isotope 1 × decimal abundance) + (mass of isotope 2 × decimal abundance)
Atomic mass of Ga = (0.6011 × 69) + (0.3989 × 71)
Atomic mass of Ga = 41.4759 + 28.3219
Atomic mass of Ga = 69.797
Atomic mass of Gallium = 69.79
Which of these statements is true?
A.The neutrons have a neutral charge and help stabilize an atom
B.The electrons have a negative charge and are in the nucleus
C.The protons have a negative charge and are in the nucleus
D.The electrons have a positive charge and orbit the nucleus in the electron cloud
Answer:
Among these statements B is the correct answer.
I really need help with these someone please help me.
3 x 10^4
8 x 10